- Click Grids | Calculate | Point Sample.
- In the Input Grid section, either select your grid-based map from the dropdown list, or click the Browse button to navigate to and select your grid file.
- In the XY Data section, either select your post/classed post map from the dropdown list, or click the Browse button to navigate to and select the data file containing your x,y locations.
- In the Data Columns section, verify the X and Y are set to the appropriate columns from the data file.
- At the bottom of the dialog, choose what column of the data file to store the z values in.
- Click OK and a worksheet is opened containing this updated data file.
- Click File | Save or File | Save As to save the changes.
1. Grid | Residuals interactive method.
2. Grid.Interpolation in automation.
3. The Grid Node Editor.
4. Using the mouse.
Method 1: Grid Residuals
Use the Grid | Residuals command to calculate the Z value.
- The first step is to create a data file of XY points (if you don't already have one) and add a column of 0's to it.
- If you do not have a data file already, click File | New | Worksheet to open the Surfer worksheet and enter in the X and Y coordinates of the points you want to use to calculate the Z value. Add a third column of 0’s.
- If you do already have a data file of XY points, click File | Open, select the data file and click Open. It will open in the worksheet. Add a third column of 0's.
- Click File | Save and save the worksheet as a Golden Software Data (*.dat) file and click File | Close to close the worksheet.
- Click Grid | Residuals, select the grid file and click Open.
- Select the data file and click Open.
- In the Grid Residuals dialog box, select the columns containing the X and Y data, and choose the column of 0's for the Z value.
- Choose a column to contain the residuals values (i.e. column D) and click OK.
- The worksheet will open and the residuals will be displayed in the specified column. The residuals returns the negative of the Z value in the grid.
- Use the worksheet Data | Transform command with the equation D = -D to reverse the sign of the residuals in column D to get the actual grid values
Method 2: Grid.Interpolate
To automate the process, use the GridInterpolate.bas script available in the Surfer installation directory under \Samples\Scripts.
Method 3: Grid Node Editor
Click Grid | Grid Node Editor, select the grid file and click Open. The grid will be displayed in the Grid Node Editor. Select any node and the X, Y and Z coordinate values for that point will be displayed at the top of the window. You can click on a different grid node to select another node, or use the arrow keys on the keyboard to move the selection.
Method 4: Using the mouse
Surfer displays the XY and Z coordinates of the cursor location in the status bar. Move your mouse over the map and view the coordinates of that location in the status bar.
Updated October 24, 2018