Surfer 7 FAQ

Version 7 History

This document covers frequently asked questions about Surfer Version 7. 

• For version 9, see Surfer FAQ for Version 9.

• For version 8, see Surfer FAQ for Version 8.

• For versions 5 and 6, running under Windows 95, 98, NT 4, 2000, Me, and XP see Surfer FAQ for Versions 5 and 6.

• For questions about older DOS versions of Surfer or running Surfer under older versions of Windows, contact surfersupport@goldensoftware.com.

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Q1.How can I get the latest version of Surfer?

Q2. How do I convert from UTM coordinates to latitude/longitude?

Q3. Does Surfer work with Windows 98?

Q4. How do I change the start directory for the Surfer 7 Scripter program? It always starts in the "My Documents" folder under Windows 98.

Q5. Does Surfer work with Windows 2000?

Q6. Does Surfer work with Microsoft Windows XP?

Q7. I am using a 16-bit version of Windows (95, 98) and I want to plot my map on large paper, but Surfer only accepts paper sizes less than 32.76 inches (83.21 cm). How can I bypass this limitation?

Q8. I want to use a BLN blanking file to blank the area outside a polygon, but when I load the BLN file as a base map, I can only fill inside the polygon.

Q9. I want to blank the grid nodes outside several polygons on a map, but the entire map gets blanked, resulting in a horizontal planar grid.

Q10. How can I reshape individual contour lines, without affecting the surrounding data?

Q11. I have created a map with a custom scale and map limits. When I overlay a new map with the existing map, Surfer changes the scale and map limits back to the defaults. Is there a way to overlay a new map onto an existing map without changing the scale and limits that I have already set?

Q12. I have a DXF file containing 3D polylines. When I import this file into Surfer, it only displays the two dimensional information. How can I get the 3D data into Surfer?

Q13. How can I create a file containing the X, Y and Z coordinates of my contour lines?

Q14. Can I control Surfer from another programming environment?

Q15. How do I handle latitude/longitude data in Surfer?

Q16. I have gridded my data set and created a contour map; however, no contour lines are displayed.  What is wrong?

Q17. How can I change the Surfer grid file blanking value to 0 or another value?

Q18. How can I print a subset area of a map?

Q19. How do I specify a scale of 1:24,000 in Surfer?

Q20. When I overlay two maps of the same type and select one, how do I tell which map is selected?

Q21. When overlaying base maps in a script how do you assign a label to each map?

Q22. I've created a map with grid lines parallel to the axes, but the grid lines stop before reaching the opposite axis.

Q23. I used the drawing tools to add lines, rectangles and text to my map, but these objects don't move when I rescale the map with the Map | Scale menu.

Q24. I downloaded DEM files from the USGS web site or the GIS Data Depot, but Surfer fails to recognize the DEM file as valid. How can I load these files into Surfer?

Q25. How are the default scale and other parameters calculated for the variogram model listed in the Grid | Data Scattered Data Interpolation | Options dialog?

Q26. I have created a post map, but the points are close together and some of the labels overlap. Is there a way to manually move them around?

Q27. How do I change the map coordinates in a DXF file within Surfer?

Q28. Is there a way to calculate the Z value in the grid [.GRD] file at particular XY locations?

Q29. How are the residuals calculated when the desired location does not fall on a grid node?

Q30. How can I make the Surfer window visible when running a script?

Q31. How can I load Surfer in a script using a different SET file?

Q32. How can I load a new SET file in a script once Surfer is running?

Q33. What gridding method should I use to grid my data file?

Q34. What's the best method for gridding a data set consisting of digitized contours?

Q35. What are the meanings of the parameters in a LVL file?

Q36. Using the Surfer Scripter, how do I set the width and height of an exported bitmap (TIF, BMP, PCX, JPG) with FileExport( )?

Q37. How can I create custom symbols for use in Surfer, Grapher, and MapViewer?

Q38. I have invested in Adobe typefaces. How do I use these type faces with Golden Software products?

Q39. How can I calculate the area between contours?

Q40. When I grid my data file using kriging, it produces a grid file with negative Z values, or with values that go beyond the Z limits in my data file. How do I change this?

Q41. How do I create a vector plot using Surfer?

Q42. In My Computer or Explorer, I double-click on a filename with the SRF extension and Surfer cannot find the file.

Q43. How is the default R-squared parameter calculated for the Radial Basis gridding method?

Q44. Does Surfer 7 support OLE linking and embedding?

Q45. How can I make the symbols in the classed post legend the same size as on the map?

Q46. The Y-axis tick labels are not printing on the HP LaserJet 4, LaserJet 5, or LaserJet 4000 under Windows 95 and Windows 98.   How can I resolve this problem?

Q47. How do I uninstall Surfer 6?  I can't find the uninstall program or a listing for uninstalling Surfer 6 in the Control Panel | Add Remove Programs menu.

Q48. I would like to make separate layers for the lakes, rivers, and rapids in the hydrography DLG for a particular quadrangle.   How do I import SDTS DLG files by attribute? 

Q49. How do I import an SDTS DLG file in lat/long coordinates?  Surfer imports it in UTM meters.

Q50. When I try to open Surfer 7 under Windows 98, I get the following error messages:

1. The OPENGL32.dll file is linked to missing export GDI32.dll:GdiSwapBuffers.
2. C:\Program Files\Golden Software\Surfer\Surfer.exe a device attached to the system is not functioning.

Q51. The command Axis.SetScale(Minimum:=0, Maximum:=8) doesn't change the axis in Surfer 7.00.

Q52. The command Axis.SetScale(335691.154, 336906.697) yields the error:  "(&H80020009) Axis exceeds coordinate space."

Q53. The Color drop-down menu in the Line Properties dialog box does not display when I click on the Color button.

Q54. The color drop-down menu in the Line Properties dialog box closes as soon as I move the mouse.

Q55. When trying to produce a post map with Proportional Scaling for symbols, I get an error message "Minimum data value cannot equal maximum". The scaling data are in the range of 0 to 10e-18.

Q56. Gridding a data set with duplicate points using the Modified Shepard's method causes the grid to extrapolate unrealistic Z values (-268,420 to 227,897) compared to the Z range in the data file (3400 to 6600).

Q57. How do I grid directional data, such as wind speed and direction?  

Q58. When I open certain Surfer 6 SRF files in Surfer 7.00, it displays the error: "Exception 10H in module Surfer.exe at 0157:004b40b".

Q59. When I attempt to grid a file, Surfer displays "Surfer Error - Failed to Create Empty Document".

Q60. Surfer messages are displaying in German, but I prefer them in English.

Q61. When I try to type in a file name with leading or trailing spaces, Surfer can not find the file.

Q62. When I try to grid a particular data file with the Kriging gridding method, I get the error message:  "Surfer Error - The system of kriging equations is singular."

Q63. The automation command Plot.PrintOut(srfFitToPage) does not fit the map to the printed page in Surfer 7.00.

Q64. Surfer 7 automation produces a different looking contour map than Surfer 6.

Q65. How can I enter a "null value" (a value that is ignored when gridding or performing mathematical calculations) into the Surfer worksheet?

Q66. How do I display the scale bar in miles or kilometers when the XY coordinates are in degrees of latitude and longitude?

Q67. How do I run a Surfer 6 script in Surfer 7?

Q68.  When I change the map limits on a post map, data point labels disappear for points that are on the edges of the map but inside the limits.  How can I display these labels?

Q69. After installation, I get an error when I try to run Surfer:
"The ordinal 6880 could not be located in the dynamic link library MFC42.DLL"

Q70. How do I specify Kriging Anisotropy in a script?  The example in the help file doesn't work.

Q71. How do I merge two or more GRD or DEM files to create a contour map?

Q72. I can't create a Surfer 7 Binary GRD using the Tag Id0x41544244listed in the users guide in Appendix C, page 566 and in the Surfer 7.00 help file.

Q73. I am having a problem printing ("Out of global memory" error, only a portion of the map prints, etc.).

Q74. My data is in curvilinear (cylindrical or spherical) coordinates. How can I get it into a format that Surfer can use?

Q75. Are there any additional scripts available for download?

Q76. Do you have more information about using variograms in Surfer?

Q77. How can I round data values in the worksheet?

Q78. Where do I find my serial number?

Q79. Is technical support free?

Q1. How can I get the latest version of Surfer?
A.  Minor updates (e.g. version 7.00 to 7.02) may be downloaded for free if your serial number is registered.  To register, enter the requested information on the Register Software page including your e-mail address, and add a note in the Comments field to Attn:  Surfer Support indicating that you would like to download the latest version.  If you have already registered, send a message to surfersupport@goldensoftware.com with your serial number.  Once your serial number is verified, we will send you download instructions.  Information about the latest version is listed on the Version History page.

Q2. How do I convert from UTM coordinates to latitude/longitude?
A. Didger 2 from Golden Software converts data and boundary files between 21 different projections, including Unprojected Latitude/Longitude and UTM.

Q3. Does Surfer work with Windows 98?
A. Yes. There have been no problems reported.

Q4. How do I change the start directory for the Surfer 7 Scripter program? It always starts in the "My Documents" folder under Windows 98.
A. Create a Shortcut in Windows for the Scripter.exe program, installed by default to:

"c:\program files\golden software\surfer\scripter\"

After creating the shortcut, right-click on the shortcut icon, chooseProperties, and specify theStart Indirectory under theShortcuttab. On some systems, theStart Inpath must be on the C: drive.

Q5. Does Surfer work with Windows 2000?
A. Yes.   Users logged in with "User" privileges may receive the following error message when trying to launch Surfer:

    "Failed to update the registry. Please try using Regedit."

To avoid the error message, the user must be logged in with "Power User" or "Administrator" privileges.

Also, a minor problem prevents the display of formatting in the gridding and variogram modeling reports, though the data remains intact.  To work around the problem, save the report to an RTF file and open it in Word or WordPad.

Q6. Does Surfer work with Microsoft Windows XP?
A. Yes, Surfer does work with the Microsoft Windows XP Operating System. There are no outstanding compatibility issues that we are aware of.

Q7. I am using a 16-bit version of Windows (95, 98) and I want to plot my map on large paper, but Surfer only accepts paper sizes less than 32.76 inches (83.21 cm). How can I bypass this limitation?
A. The 16-bit versions of Windows use a coordinate system that limits the maximum paper size. The 32-bit versions of Windows (NT) do not have this limitation. There are several ways to work around the problem:

• Design your map at half scale, and print at 200% scale.

To print a map on 24"x 40" paper at a scale of 1.0 in. = 1.5 Map units, designate the paper size in Surfer as 12"x 20", and design the map at half scale (1.0 in. = 3.0 Map units). When printing the map, specify 200% scale in the Print dialog box. The map is printed at a scale of 1.0 in. = 1.5 Map units on 24"x 40" paper.

• Use a text editor to add a new line to the Surfer INI file* that reads:

LogPerInch=500

Add the line to the [Settings] section of the surfer.ini file.

Save the changes, and restart Surfer. This method doubles the maximum paper size to 64 inches, but it also doubles the size of all SRF files created without the LogPerInch=500 setting.

Surfer 8 eliminates this restriction.

Q8. I want to use a BLN blanking file to blank the area outside a polygon, but when I load the BLN file as a base map, I can only fill inside the polygon.
A. The Map | Base Map menu does not have the ability to fill outside a polygon, but there are other methods to consider:

Modified file in BLN format

11
0.0 0.0		"(x1,y1)"
9.0 0.0
9.0 7.0
0.0 7.0
0.0 0.0		"Repeat (x1,y1) to close outer polygon."
1.0 1.0		"Start internal polygon.
2.0 1.0
2.0 2.0
1.0 2.0
1.0 1.0		"Close internal polygon.
0.0 0.0		"Repeat (x1,y1) to close outer polygon."

The BLN format draws the connecting line from the internal polygon to the repeated (x1,y1) point at (0,0). Set the line style to Invisible for this base map, or use the BNA format, which does not draw the connecting line:

Modified file in BNA format

"","",11
0.0 0.0
9.0 0.0
9.0 7.0
0.0 7.0
0.0 0.0
1.0 1.0
2.0 1.0
2.0 2.0
1.0 2.0
1.0 1.0
0.0 0.0

Q9. I want to blank the grid nodes outside several polygons on a map, but the entire map gets blanked, resulting in a horizontal planar grid.

A. It may be that the area outside polygon A is inside polygon B, and vice versa, causing the entire map to be blanked. Combine the two polygons into a single polygon, and repeat the first vertex of the first polygon at the end of the second polygon to create a single combined polygon. Change the header of the combined polygon to reflect the total number of vertices in both simple polygons, plus the repeated first vertex. If you load the combined polygon as a base map, a line is drawn back to the first vertex, so you may need to keep both versions of the BLN available, the separate polygons to use as a base map, and the combined polygon to use for blanking purposes.			Blanking the area outside multiple polygons blanks the entire grid.
.
two separate polygons 5 0 'Polygon A 1.0 1.0 1.0 2.0 2.0 2.0 2.0 1.0 1.0 1.0 5 0 'Polygon B 3.0 3.0 3.0 4.0 4.0 4.0 4.0 3.0 3.0 3.0	one combined polygon 11 0 'Polygon A 1.0 1.0 'x1 y1 1.0 2.0 2.0 2.0 2.0 1.0 1.0 1.0 3.0 3.0 'Polygon B 3.0 4.0 4.0 4.0 4.0 3.0 3.0 3.0 1.0 1.0 'repeat x1 y1		Editing the blanking file to combine the polygons resolves the problem.

Q10. How can I reshape individual contour lines, without affecting the surrounding data?
A. Use one of the following methods:

• Choose the Grid | Grid Node Editor menu, and specify the grid file name to display a contour map of the grid file. By default, a small cross is displayed at the grid nodes. Click on a grid node you wish to modify, and Surfer displays the X, Y, and Z coordinates of the selected grid node at the top of the grid editor window. Alter the Z value of a grid node by typing in a new value into the Z box at the top of the window. This will not affect the Z values of the surrounding grid nodes. Save the modified grid file when you are finished, and create a new map with the new grid file, or substitute the new grid file in an existing map.
• If you don't need the map coordinates in the resulting file, copy the contour map to the clipboard, choose the Edit | Paste Special menu to paste as aPicture, enable theBreak Apart Metafilesoption, click onPaste, and click the mouse at the desired paste location. Choose the Arrange | Break Apart menu to break apart the Composite, click on the line to be reshaped, and choose the Edit | Reshape menu to display the vertices in the contour line. Click on a vertex and drag it to a new location to reshape the polyline.

Q11. I have created a map with a custom scale and map limits. When I overlay a new map with the existing map, Surfer changes the scale and map limits back to the defaults. Is there a way to overlay a new map onto an existing map without changing the scale and limits that I have already set?
A. Changing the Surfer SET file can modify the default behavior of the program. Open the SET file in a text editor to view the structure of the file and make changes, or change the defaults in the File | Preferences | Default Settings menu. Before creating or opening the map containing the desired scale and limits, choose the File | Preferences | Default Settings menu and scroll to the Map Scale and Map Limits section near the bottom of the SET file:

Click on the plus sign + to the left ofMap Scale, selectxDatPerPUand change theSetting PersistencetoCurrent Session Only. Repeat for each parameter underMap ScaleandMap Limits. Save the changes to the Surfer.set file.

Create or open an existing map. Make changes to the limits and scale to write the settings to the SET file. Overlay a new map and the scale and limits from the first map is maintained. To reset the settings for a map covering a new area, close and restart Surfer.

Q12. I have a DXF file containing 3D polylines. When I import this file into Surfer, it only displays the two dimensional information. How can I get the 3D data into Surfer?
A. Surfer does not read the Z information in 3D DXF files directly. The script dxf2xyz.bas extracts the X,Y and Z information from 3D DXF polylines containing Z information at each vertex and creates an XYZ DAT file. Grid the data file and create a wireframe map to display the data in 3D in Surfer. This script does not work with DXF files that contain 3D information only in the polyline header, or in XYZ points.

Q13. How can I create a file containing the X, Y and Z coordinates of my contour lines?
A. To export contours to a 3D DXF file, create a contour map, select it, then choose the Map | Contour Map | Export Contours menu.

Q14. Can I control Surfer 7 from another programming environment?
A. Yes. Surfer can be completely controlled by any Automation-capable programming language, including Visual Basic, Visual Basic for Applications (that ships with the Microsoft Office suite), or the Scripter programming language included with Surfer.  Scripter is very similar to VBA.   Most modern compilers include some facility for calling Automation-capable applications, including Visual C++.  Check your language documentation for Automation or Active-X Automation support.  See the following files included with Surfer 7:

The directory for these files is the \Samples\ directory under the main Surfer directory, which defaults to "c:\Program Files\Golden Software\Surfer\Samples\".

Q15. How do I handle latitude/longitude data in Surfer?
A. Post your data in unprojected latitude/longitude using decimal degrees, with west and south directions shown as negative values. Latitude is the Y and longitude is the X. For example, 105 degrees 30 minutes west would be represented as -105.5 degrees. To convert from degree-minute-seconds (dms) units to decimal degrees (d.dd), use the formula:

d.dd = d + (m / 60) + (s / 3600)

Q16. I have gridded my data set and created a contour map; however, no contour lines are displayed.  What is wrong?
A. This condition has several possible causes:

• Check theLevelsin the Contour Map dialog box to see that at least one of the contour levels is within the range of your gridded data. For example, a contour map appears blank if there are contours at 0 and 100 while the gridded data ranges from 20 to 80.
• Select the map and choose the Map | Limits menu. If the check box forUse Data Limitsis not checked, check this box and click OK to reset the map XY limits to include all the data in the map.

Q17. How can I change the Surfer grid file blanking value to 0 or another value?
A. Convert the grid file from binary to ASCII, and use a text editor to search for the blanking value and replace it with the desired value.

Step by Step Instructions:

1. Choose the Grid | Convert menu to display the Open Grid dialog box.
2. Specify the name of the grid file to be converted and clickOpen.
3. Enter a new grid file name in the Save Grid As dialog box, and change theSave as Type, and click onOK.
4. Open the ASCII GRD file in a text editor or word processor.
5. Search for the blanking value 1.70141E+038 and replace it with the desired value.

Save the file in an ASCII TXT format with the GRD extension.
The new GRD file is ready to be used in a map or grid calculation.

Q18. How can I print a subset area of a map?
A. Choose the Map | Limits menu and specify the x and y minimum and maximum coordinates of the area of interest. Choose the Map | Scale menu to specify the size of the map, then File | Print.

Q19. How do I specify a scale of 1:24,000 in Surfer?
A. Surfer defines the scale in terms of the units of the XY coordinates in the data file. For example, if the units in the data file are feet, then a scale of 1:24,000 is calculated as follows:

1:24,000
1 inch = 24,000 inches
1 inch = 2,000 feet

Q20. When I overlay two maps of the same type and select one, how do I tell which map is selected?
A. This example uses base maps to illustrate the procedure, but it works with all 2D map types:

1. If the Object Manager is not visible, enable it with the Edit | Object Manager menu or Object Manager tool .
2. Select the first base map in the Object Manager tree and change one of the object properties, such as line color, to identify the map in the window.
3. Choose the Edit | Undo menu to undo the change, right click on the first "Base" in the Object Manager tree, and enter a new name for the base map.
4. Repeat for all other maps you wish to name.

or

1. Select a base map with Ctrl+Click (hold the Ctrl key down when clicking the left mouse button). In the lower left corner of the window, the status bar should display "Map: Base".
2. Choose the Edit | Object ID menu to specify a name.
3. Repeat for all other maps you wish to name.

Q21. When overlaying base maps in a script how do you assign a label to each map?
A. There are two steps to naming your maps:

1. Name the "frame" or "container" that holds the map and axes
2. Name the "contents" or "overlays", i.e. the actual maps.

When you click on a map interactively in Surfer, the status bar in the lower left corner of the window reports the map frame to the left of the colon and the overlay to the right of the colon, as in "Map: Base". To name the parameters in the Scripter, first name the map

frame (left side of colon).
...MapFrame1.Name = "Frame1"

The next step is to name the overlay map (right side of colon)
...ContourMap.Name = "Base97"

If you stop the script here, the ID displayed in the status bar is:
..."Frame1: Base97"

For an example script that demonstrates how to name components of a map, use the Scripter script Naming.BAS.

Q22. I've created a map with grid lines parallel to the axes, but the grid lines stop before reaching the opposite axis.
A. Under theScalingtab or button in the Axis Properties dialog box, change the tick minimum and maximum values to match the axis minimum and maximum.

Q23. I used the drawing tools to add lines, rectangles and text to my map, but these objects don't move when I rescale the map with the Map | Scale menu.
A. Convert the objects to "map" objects with map coordinates and overlay on the existing map.

• Points: Digitize points to a DAT file using the Map | Digitize menu, then save with the .DAT extension. Display these points with a post map. Select both maps and use the Map | Overlay Maps menu to combine the maps.
• Text: Save text in a DAT file after digitizing the location of the text using Map | Digitize. Click on the map to record the desired location of the text, type a comma after the XY coordinate in the DIGIT.DAT window, and type the text surrounded by double quotes. When finished digitizing the text locations and adding text, save the file as a DAT file. Load the DAT file as a post map specifying column C as the Label column, and overlay with the existing maps.
• Lines and Polylines: Convert lines to a BLN file format using the Map | Digitize menu to digitize the points. Surfer 7 adds the headers automatically when saved to the BLN format if you insert a blank row between polylines. Surfer 6 requires adding the adding the BLN header manually in the DIGIT.DAT window and saving to a BLN extension. Load the BLN file as a base map and overlay with existing maps.
• Objects with Known Coordinates: Export the drawing as a DXF file with map coordinates. The Export DXF dialog box lets you specify page coordinates under the Page Rectangle heading and corresponding map coordinates under the DXF Rectangle heading. Load the DXF file as a base map and overlay it with existing maps.

Q24. I downloaded DEM files from the USGS web site or from the GIS Data Depot, but Surfer fails to recognize the DEM file as valid. How can I load these files into Surfer?

A. Surfer 7 recognizes ASCII DEM (1° x 1° - 1:250,000 scale with 3 arc-sec grid spacing, 7.5 minute - 1:24,000 scale with 30m grid spacing), GTOPO30 DEM (40° x 50° - 1:1,000,000 scale with 30 arc-second spacing), and SDTS DEM (size and scale vary) formats. These files are often compressed and archived in a .tar.gz format (both tar'd and gzip'd). Files must be extracted prior to use within Surfer. The WinZip program is a good choice for extracting the files, but disable the option to use "TAR file smart CR/LF conversion" in the Options | Configuration | Miscellaneous menu prior to extracting the files. Other possible pitfalls include:

• Some browsers change the file extension from .tar.gz to _tar.gz.  Use the .tar.gz extension for easier WinZip extraction
• The GTOPO30 format requires the DEM, HDR, and STX files or Surfer issues a message that the file is not a valid DEM file.
• GTOPO30 DEM files are typically 6000 x 4800, requiring at least 210 MB of RAM to display. The Grid | Extract menu extracts a subset of the DEM covering either a smaller area or sampling every nth grid node.
• The SDTS format requires all the DDF files contained within the .tar.gz archive. Select any one of the DDF files to extract the information from all the DDF files extracted from the archive.
• Some SDTS DDF files are DEM files and others are DLG boundaries. These two files are not interchangeable in Surfer; DEM files can be used any place GRD files are used, and DLG boundaries are imported using the Map | Base Map menu. The type of archive can be determined by the presence of key files. The SDTS DEM archive contains a file with a name in the form xxxxCEL0.DDF. The SDTS DLG archive contains a file in the form xxxxLE##.DDF.
• Support for the "new SDTS DEM format available on the GIS Data Depot was added to Surfer 7.05.  This new version also supports DEM files with 10m grid spacing.  How can I get the latest version of Surfer?

Q25. How are the default scale and other parameters calculated for the variogram model listed in the Grid | Data Scattered Data Interpolation | Options dialog?
A. The default parameters are set to 1. Use the Grid | Variogram | New Variogram menu to model your data and get values for your data set, and click theGet Variogrambutton in the Kriging Options dialog box to transfer the calculated parameters from the variogram to the kriging algorithm.

Q26. I have created a post map, but the points are close together and some of the labels overlap. Is there a way to manually move them around?
A. Isolate the labels that overlap others and move them to a separate column in the worksheet. Create the first Post map with the label position set at your choice. Create a second post map with labels taken from the new column and the label position set to a different location than the first post map. Overlay the two maps using the Map | Overlay Maps command. You may have to adjust the label position, possibly using the User Defined function for label position, before you are satisfied with the results. Changing the label position setting affects all the points in a post map.

Q27. How do I change the map coordinates in a DXF file within Surfer?
A. Use the page coordinates of two calibration points with known map coordinates on your map to create a new DXF with the changed coordinates. Choose the File | Import menu to load the DXF file and display it without axes. Zoom In on the first known point and write down the XY page coordinates from the status bar at the bottom of the Plot window. Zoom Out, scroll to the next point and write down the page coordinates. Choose the File | Export menu, and specify a new file name with the .DXF extension to display the AutoCAD DXF Export dialog box. Type in the page coordinates under the "Page Rectangle" area and the corresponding map coordinates under the "DXF Rectangle" area. Although the dialogue box prompts for theLower LeftandUpper Rightpoints, you may enter any two map points. Set theScaling SourcetoApplication,FormattoASCII, and uncheck all the check boxes in the lower left corner. ClickOKto create the new DXF file. To load the file into Surfer with map coordinates, use the Map | Base Map menu.

Q28. Is there a way to calculate the Z value in the grid [.GRD] file at particular XY locations?
A. Use the Grid | Residuals command to calculate the Z value. Create a data file with the XY locations, and add a column of 0's. Grid | Residuals subtracts zData - zGrid, so using a column of 0's for zData returns the negative of the Z value in the grid.

Q29. How are the residuals calculated when the desired location does not fall on a grid node?
A. Surfer uses bilinear interpolation between grid nodes.

Q30. How can I make the Surfer window visible when running a script?
A. To make the Surfer window visible, set the Application object’s "Visible" property to True:

Set srf = CreateObject("Surfer.Application")
srf.Visible = True

Use the Task Manager to end the execution of any invisible copies of Surfer.

Q31. How can I load Surfer in a script using a different SET file?
A. Use the shell( ) command to specify the SET file on the command line, then use the GetObject( ) command to use the existing instance of Surfer.

ExeFile = "d:\program files\golden software\surfer\" + "surfer.exe"
SetFile = "d:\program files\golden software\surfer\" + "new.set"
Shell(ExeFile+" /Set "+Chr(34)+SetFile+Chr(34),1)
Wait 5
Set Srf = GetObject(,"Surfer.Application")

Q32. How can I load a new SET file in a script once Surfer is running?
A. Exit Surfer then use the shell( ) and GetObject( ) commands below.

Shell("c:\apps\surfer7\surfer.exe /set c:\apps\surfer7\dan.set",1)
Wait 4 'Wait a few seconds to allow Surfer to start
Dim Surf As Object
Set Surf = GetObject(,"Surfer.Application") 'Connect to the running instance of Surfer

Q33. What gridding method should I use to grid my data file?
A. The default gridding method, kriging with a linear variogram, was selected as a good method for the majority of data sets.

Q34. What's the best method for gridding a data set consisting of digitized contours?
A. No one method is the "best", but you can improve the results of gridding a digitized contour data set by making sure sufficient data points are distributed throughout the map area. If there is a "C"-shaped contour without other contours inside the "C", the entire C is gridded as a flat area. The same thing happens with a closed contour. Use the Map | Digitize menu to digitize additional points within the "C"-shaped contours and closed contours and add them to your data file.

Q35. What are the meanings of the parameters in a LVL file?
A. The parameters are defined as follows:

Level = Z or contour value.
Flags = 0 1 2 3 for none, labeled, hachured, both.
LColor = Line color by name "Red" or RGB "R255 G0 B0".
LStyle = Line style, e.g. "Solid", "Invisible".
LWidth = Line width in inches x 1000 so 0.01" = 10.
FFGColor = Fill Foreground Color by name or RGB.
FBGColor = Fill Background Color by name or RGB.
FPattern = Fill Pattern by name, e.g."12.5% Black" "Vertical".
FMode = 1 transparent, 2 opaque.

Q36. Using the Surfer Scripter, how do I set the width and height of an exported bitmap (TIF, BMP, PCX, JPG) with FileExport( )?
A. Use the PlotDocument.Export() command with the following options:

Since the Export Options dialog isn't displayed when the program is driven from an automation script, an options string can be specified in the script. The string consists of comma-separated parameters, which specify the behavior of the various export options. A typical example would be:

"Defaults=1,Width=640,Height=480,ColorDepth=4"

This would set all export options to their default values, then set the bitmap width to 640 pixels, the bitmap height to 480 pixels and the color depth to 4 (i.e., 256 colors).

All the available options are listed here for Bitmap export. These can also be located in the Online Help.

Option	Action	Default
Defaults=1	Set all options to their default values	No
ForgetOptions=1	Don't remember options for later use	No
Width=N	Set N pixels as the output bitmap width	Screen Resolution
Height=N	Set N pixels as the output bitmap height	Screen Resolution
HDPI=N	Set N pixels per inch as the horizontal output resolution. May not be used if Width is specified.	None (uses default Width)
VDPI=N	Set N pixels per inch as the vertical output resolution. May not be used if Height is specified.	None (uses default Height)
ColorDepth=N	Set color depth (WIN32 only). Valid Values: 1: Monochrome 4: 16 Colors 8: 256 Colors 24: True Colors	Color Depth of the Video Display
Automatic=1	Automatic compression (for JPEG)	Yes
Quality=N	Set compression quality 0 - 100 (for JPEG)	100 (highest quality)

Q37. How can I create custom symbols for use in Surfer, Grapher, and MapViewer?
A. Our software can use TrueType fonts for symbols, a TrueType font editor will let you create your own symbols including:

• Softy (shareware)
• TypeTool from Pyrus (commercial)

Surfer, Grapher, and MapViewer also use the symbol sets and Altersym editor from the DOS versions of Surfer and Grapher at the Golden Software FTP site.

Q38. I have invested in Adobe typefaces. How do I use these type faces with Golden Software products?
A. Golden Software's applications only support TrueType scalable typeface technology. If you have a significant investment in Adobe Type 1 faces (i.e., you are using ATM under Windows), we recommend converting them to TrueType format so they may be used with Golden Software products and other Windows programs. We recommend the TypeTool program from Pyrus for this purpose.

Q39. How can I calculate the area between contours?
A. Choose the Grid | Volume menu to generate a volume and area report using the GRD file as the "Upper Surface" and the Z level of the first contour as the constant "Lower Surface". Record the "Positive Planar Area" value from the report. Next, generate a second report with the same GRD file as the Upper Surface and the Z level of the second contour as the Lower Surface. Record the Positive Planar Area value from the second report, and subtract from the first value to get the area between the two contours. The contarea.bas script calculates the area between evenly spaced levels automatically.

Q40. When I grid my data file using kriging, it produces a grid file with negative Z values, or with values that go beyond the Z limits in my data file. How do I change this?
A. The kriging gridding method was designed to analyze data trends and extrapolate in areas of no data. There are several methods to eliminate this effect.

• Use the Grid | Math menu to eliminate negative values. First select your existing grid file (A), specify a new name for the output grid file (C), and the formula C = max(A,0). This formula converts all negative Z values to 0 in the new grid file. Use this method for all values including 0.
• Choose a different gridding algorithm that does not extrapolate beyond the Z limits in the data file. Inverse Distance to a Power and Triangulation with Linear Interpolation are two such methods.
• If your data range over several orders of magnitude, it may be beneficial to transform your Z values in the worksheet to logarithmic values. Open the data file in the worksheet and choose the Compute | Transform menu. If your data are in column C, and column D is blank, use the formula D = log10(C) to calculate the log base 10 of the Z values. Save the worksheet, and create a grid using column D as the source of Z values. This method may create negative log10 values, but these values represent small positive Z values. e.g. log10(Z) = -2, then Z = 0.01.

Q41. How do I create a vector plot using Surfer?
A. Surfer 7 creates vector plots from a grid file, or from two grid files individually containing direction and magnitude information by using the Map | Vector Map | New 1-Grid Vector Map or the Map | Vector Map | New 2-grid Vector Map commands.

Q42. In My Computer or Explorer, I double-click on a filename with the SRF extension and Surfer cannot find the file.
A. This feature has been added to Surfer 7.02.  To qualify for a free download of this update, refer to the Updating Surfer question listed in this FAQ.   The Surfer History web page has a list of new features and fixes in each version.

Q43. How is the default R-squared parameter calculated for the Radial Basis gridding method?
A. The default value is calculated as follows:

(Length of Diagonal of the data extent) ^ 2 / (25 * number of data points)

This value was chosen for robustness (to work with most data sets).

Q44. Does Surfer 7 support OLE linking and embedding?
A. Surfer 7 does not support OLE linking and embedding.  Our testing found stability problems related to the way different applications implement the OLE specification.  For now, we have decided to forego linking and embedding until a more robust mechanism is available.

Q46. The Y-axis tick labels are not printing on the HP LaserJet 4, LaserJet 5, or LaserJet 4000 under Windows 95 and Windows 98. How can I resolve this problem?
A. Surfer 7.01 incorporates a fix for this problem.  To work around the problem in Surfer 7.00, close Surfer, open the Surfer.ini file in Notepad, and remove the semi-colon from the beginning of the following line:

                                       ;Windows Picture:Printer:Text=0x8000

Save the changes, restart Surfer and print the map.

Q47. How do I uninstall Surfer 6?  I can't find the uninstall program or a listing for uninstalling Surfer 6 in the Control Panel | Add Remove Programs menu.
A. Surfer 6 did not come with an uninstall program.  You can delete the files in the Surfer 6 directory using the Windows Explorer or My Computer.

Q48. I would like to make separate layers for the lakes, rivers, and rapids in the hydrography DLG for a particular quadrangle.   How do I import SDTS DLG files by attribute? 
A. Use the Map | Base Map menu command, specify one of the DDF files in the hydrography DLG, and click Open to display the SDTS-TVP Import Options dialog box.  In the Selection Criteria group, change the By Attribute Name from (ALL) to ENTITY_LABEL, and enter the attribute code (major plus minor code) in the Value edit box.  Lakes are 0500421, rivers are 0500412, and rapids are 0500400.  For a complete list of USGS DLG attribute codes, refer to Appendix B of the Data User Guide.

Q49. How do I import an SDTS DLG file in lat/long coordinates?  Surfer imports it in UTM meters.
A.  In the SDTS-TVP Import Options dialog box, click on the check box for Unproject Coordinates, then click OK.

Q50. When I try to open Surfer 7 under Windows 98, I get the following error messages:

1. The OPENGL32.dll file is linked to missing export GDI32.dll:GdiSwapBuffers.
2. C:\Program Files\Golden Software\Surfer\Surfer.exe a device attached to the system is not functioning.

A. Another program on your system may have changed the version of your OPENGL32.DLL file, causing it not to work with Surfer 7.   In the Windows\System directory, rename the OpenGL32.dll to OpenGL32.old. Re-install Surfer 7 and copy the new OpenGL32.dll from the Windows\System directory to the Surfer 7 directory.

Q51. The command Axis.SetScale(Minimum:=0, Maximum:=8) doesn't change the axis in Surfer 7.00.
A. Surfer 7.00 has trouble with named parameters that have the same name as object properties and methods.  Surfer 7.01 resolves the problem.  To work around the problem in Surfer 7.00, use positional parameters instead of named parameters:  Axis.SetScale(0, 8)

Q52. The command Axis.SetScale(335691.154, 336906.697) yields the error:  "(&H80020009) Axis exceeds coordinate space."
A.  A problem in the code that validates the parameters was fixed in Surfer 7.01.

Q53. The Color drop-down menu in the Line Properties dialog box does not display when I click on the Color button.
A. There may be a conflict with another program.  Close all programs, including virus checkers and jukebox programs that may appear on the desktop and in the system tray on the task bar, and restart Surfer.  A known conflict exists with the Exceed X Windows emulation program.

Q54. The color drop-down menu in the Line Properties dialog box closes as soon as I move the mouse.
A. Turn off the option Activation Follows Mouse option in the TweakUI program.

Q55. When trying to produce a post map with Proportional Scaling for symbols, I get an error message "Minimum data value cannot equal maximum". The scaling data are in the range of 0 to 10e-18.
A. Surfer requires the difference between the zMax and zMin to be at least 1e-5 (0.00001).

Q56. Gridding a data set with duplicate points using the Modified Shepard's method causes the grid to extrapolate unrealistic Z values (-268,420 to 227,897) compared to the Z range in the data file (3400 to 6600).
A. Change the duplicate setting from "All" to "Average" or "Delete First".

Q57. How do I grid directional data, such as wind speed and direction? 
A. Calculate the X and Y components of the speed/direction data in the Surfer worksheet, grid these components separately, and display as a 2-Grid Vector map.  The formulas for calculating the X and Y components are:

    X = r * sin(d2r(a)),  Y = r * cos(d2r(a))

where
    X = X component
    Y = Y component
    r = wind speed
    a = wind direction (0° = north, 90° = east)
    d2r converts degrees to radians for the worksheet sin and cos functions.

Q58. When I open certain Surfer 6 SRF files in Surfer 7.00, it displays the error: "Exception 10H in module Surfer.exe at 0157:004b40b".
A. Surfer 7.01  fixes this problem.

Q59. When I attempt to grid a file, Surfer displays "Surfer Error - Failed to Create Empty Document".
A. This error is caused by another program changing the Windows system file riched32.dll.  Copy this file from the Surfer\Scripter directory to the Surfer directory so the program will use the unchanged version.

Q60. Surfer messages are displaying in German, but I prefer them in English.
A. Some programs install the system file mfc42loc.dll in the Windows system directory to control the language of the output messages.  Rename this file to a new name, such as mfc42loc.old, to prevent Windows from using this file.  This action may have an effect on the program that installed this file.

Q61. When I try to type in a file name with leading or trailing spaces, Surfer can not find the file.
A. The Windows File Open dialog boxes trim the leading and trailing spaces.  Add quotes around the file name to overcome the problem.

Q62. When I try to grid a particular data file with the Kriging gridding method, I get the error message:  "Surfer Error - The system of kriging equations is singular."
A. This message may indicate that the system of equations is unsolvable due to extreme differences between closely spaced data pairs or by the position of the data points, such as a co-linear arrangement.  Using faults and breaklines also makes the algorithm more likely to fail.  Change the gridding method or settings to work around the problem.  In addition, Surfer 7.01 has added code that may reduce the occurrence of this error message.

Q63. The automation command Plot.PrintOut(srfFitToPage) does not fit the map to the printed page in Surfer 7.00.
A. Surfer 7.01 has a fix for this problem.   To work around the problem in Surfer 7.00, subtract 1 from the enumeration constant:

        Plot.PrintOut(srfFitToPage - 1)

Q64. Surfer 7 automation produces a different looking contour map than Surfer 6.
A. Surfer 7 calculates default Kriging Scale and Length differently than Surfer 6.  Specify the the values when gridding to duplicate the results from Surfer 6.

Q65. How can I enter a "null value" (a value that is ignored when gridding or performing mathematical calculations) into the Surfer worksheet?
A. Surfer ignores any text strings (non-numeric values) when gridding and when performing Data | Transform in the worksheet.  Any of the following can be used:

            "-9999", N/A, "no data", x99

In a text editor, program, or script, add quotes around a number to designate it as a text string.  In the worksheet, insert a single quote (apostrophe) at the beginning of the number to convert it to text.  Quotes around a text string with spaces insure that the entire string is read as a single item.  A mix of numbers and text without spaces is read as a text string.

Q66. How do I display the scale bar in miles or kilometers when the XY coordinates are in degrees of latitude and longitude?

A. First convert the map X Scale and Y Scale to Cartesian coordinates (i.e. miles, feet, kilometers, meters), because one degree of latitude does not cover the same number of miles as one degree of longitude. For an approximate conversion from latitude and longitude degrees to miles or kilometers, use the following formulas for a spherical projection:   1 degree latitude  = 110.6 km                      = 68.703 mi   1 degree longitude = 111.3km * cos(latitude)                      = 69.172mi * cos(latitude) To set the scale bar of a map, use the formulas to convert latitude and longitude to the desired coordinates. For the map of Nevada USA included with Surfer (nv.gsb) the center of the map is approximately (-117, 39). Using the formulas:   1 degree latitude  = 68.703 miles   1 degree longitude = 69.172 * cos(39)                       = 53.757 miles To set the X and Y to the same scale in miles, select the map and choose the Map | Scale menu. Disable the Proportional XY Scaling checkbox in the lower left corner of the Scale dialog box. If the X scale is set to 1.0 in = 1 Map units (degrees longitude), calculate the ratio of X to Y as 53.757mi / 68.703mi = 0.78245. Specify the Y scale as 1.0 in = 0.78245 Map Units. The default scale bar is created in degrees with a Cycle Spacing = 1 and Label Increment = 1. To change the scale bar to 50 mile increments, change the Cycle Spacing to 50mi / 53.757mi per degree or 0.93 (degrees) and the Label Increment to 50 (miles).

• Surfer 7 Scripter treats a variable with a suffix as the same variable without the suffix, and Surfer 6 treats them as different variables.

Surfer 7 Scripter
    DIM a As String
    a = "Text1"
    a$ = "Text2"
    Debug.Print a$;" ";a 
   'Prints "Text2 Text2", a$ = a

Surfer 6 Scripter
    DIM a As String
    DIM a$ As String
    a = "Text1"
    a$ = "Text2" 
    print a;" ";a$ 
   'Prints "Text1 Text2", a$ <> a

Q68. When I change the map limits on a post map, data point labels disappear for points that are on the edges of the map but inside the limits.   How can I display these labels?
A. Increase the map limits to include the area where the labels plot.