There are four gridding methods in Surfer that support gridding collinear data. If you are encountering the error "Insufficient data (collinear)" in the Grid Data dialog, select one of the four gridding methods listed below instead of the current selected gridding method:

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

Surfer 14 and older versions cannot grid data if all of the points are collinear (all in a straight line). 

To work around this in older versions, either add more data points not in the line, or change one of the values by a small amount (e.g. 0.001), save the changes, and grid the data.

Updated October 2021