To Create a Polygon Mask

1. Make sure a map is selected in your project.

2. On the ChemAnalyse menu, click Classify by region|Create polygon mask. The system displays the Create a polygon file dialog box.

3. Specify the polygon File Name and then select Inclusive or Exclusive?. Click the New file button. The system displays the Define polygon dialog box.

4. Click the OK button and then digitise the area of interest. Right click the mouse when finished and select Done from the popup menu.

5. Repeat steps 2 to 4 above, but click Append on the Create a polygon file dialog. This will include separate polygons in the same polygon file. Repeat until you have digitised the areas of interest.