GGU-GEO-GRAPH: "Gradients" button

Using this button you can generate a gradient field. The gradients are computed from the three values, one at each corner, for each triangle respectively. The length of the gradients can be controlled in the dialog box.

Further gradient presentation format and labelling preferences can be specified in the dialog box that opens when you press the "Presentation format" button. The "Frame triangle mesh", "Show triangle mesh", "Show points" and "Show values" switches correspond to the settings for contour lines described in Section "Presentation format".

• "Label gradients"
  The gradients are labelled with the gradient value.

• "Rotate text by 90 degrees"
  Depending on the orientation of the gradient arrows, the labelling may be above the arrows. It may be useful for a clear presentation to rotate the labelling by 90°.

• "Fill arrowheads"
  The gradient arrowheads are colour-filled with the colour given for gradients in the "Graphics preferences/Pen colour and width" menu item. If a different colour is required it must be altered here.

• "Gradient format"
  Further settings for gradient visualisation can be made in the following input fields. Negative numbers in the "No. of decimal places" field generate exponential labelling, whereby the negative number represents the number of decimal places. Positive numbers generate normal labelling with x decimal places. A "0" generates labelling in integer format. The text entered in "Heading" is used as the heading in the general legend and need not be re-entered in the dialog box described in Section “"General legend" menu item“. The "Heading" input box there remains empty.