Numeric value tags may be formatted with a simple picture format such as:

ch.Set 'vpic' '##0.00%'

To show the tags to 2 decimal places with a trailing % symbol. When contour lines are drawn on scatterplots, this format specification is used to create the labels on each line.

Piecharts
This format specification is also used for the numeric sector labels on piecharts if you set the ‘values’ style here. You can also use a simple format such as ‘XXXXXXX;’ to get text labels wrapped into a limited width, or ‘XXXXXX’ which will simply truncate them, suffixed with an ellipsis if necessary.

In addition, you may want to merge the sector labels with the sector values. You can do this with a format such as ‘The XL = ##0’ which will take each sector in turn and substitute the corresponding label into the value string at the XL marker.

See also ...
Picture formatting