gvSIG-Desktop 1.1. Manual de usuario.

Classification field: A pull-down menu appears in which you can select the layer’s table of attributes’ field, which contains the data to be sorted. The field must be numerical because this is a gradual classification (by ranges of values).

Number of Intervals: This must indicate the number of ranges or intervals that define its classification.

Start colour and End colour: Select the colours to be graduated. The start colour is for the lowest values and the end colour is for the highest values.

Computing intervals: When you have defined the previous options, click on the “Compute intervals” button to see the legend’s end result. The symbols and the labels which appear by default can be modified by clicking on them, as in the previous cases.

Add: New ranges can be added to the computed intervals.

Remove all / Remove: This allows all (Remove all) or some (Remove) of the elements in the legend to be removed.

Type of intervals: From gvSIG version 0.4 onwards, you can specify the interval type you wish to divide the information into in order to represent it. You can choose between the following options:

• Equal intervals: The number of intervals are specified and the sample is divided into this number of equal intervals.
• Natural intervals: The number of intervals is specified and the sample is divided into this number of intervals according to the Jenk method of optimising the natural breaks for the intervals.
• Quantile intervals: The number of intervals is specified and the sample is divided into this number of intervals but the values are grouped together according to their order number.