Resolve "Insufficient data (collinear)" gridding error in Surfer

The error message "Insufficient data (collinear)" during gridding indicates that all of the points in the selected dataset lie along a perfectly straight line. Three solution options for this error message are outlined below.

1. Use a different gridding method

The default Kriging algorithm does not support gridding collinear data but there are four gridding methods in Surfer that do. If your data does lie along a line, select one of the four gridding methods listed below to create your grid file:

• Inverse Distance
• Nearest Neighbor
• Moving Average
• Data Metrics

Note: This solution will not work in Surfer 14 and older versions

2. Adjust the position of one point

This error message is triggered only when all points lie along a perfectly straight line.  Therefore, even a very slight position adjustment may resolve it. If the accuracy of your map allows it, you may change the X or Y coordinate for one point by a small amount (e.g. 0.001) in your input file, save the change, and re-grid the data using your preferred gridding method.

3. Double check the column assignments

If you are receiving this error message and your data is not collinear, Surfer may be using the wrong data columns during gridding.  By default, Surfer will using Column A as the X variable, Column B as the Y variable, and Column C as the Z variable.  If these are not the correct columns, try gridding the data again and double check that the correct columns are assigned.  

If you are unsure which columns to use, click the View Data button to preview the file.

Once the correct columns are assigned you can also double check the data distribution on the Grid Data - Options page.  Click Next until a preview of your data is displayed to ensure the point distribution aligns with your expectations.

If the solutions above do not meet your needs or you are continuing to see the error message even after making these changes, please email support@goldensoftware.com to let us know and include your data for investigation if possible.