<P> An isoflor is an isopleth contour connecting areas of comparable biological diversity . Usually, the variable is the number of species of a given genus or family that occurs in a region . Isoflor maps are thus used to show distribution patterns and trends such as centres of diversity . </P> <P> In economics, contour lines can be used to describe features which vary quantitatively over space . An isochrone shows lines of equivalent drive time or travel time to a given location and is used in the generation of isochrone maps . An isotim shows equivalent transport costs from the source of a raw material, and an isodapane shows equivalent cost of travel time . </P> <P> Contour lines are also used to display non-geographic information in economics . Indifference curves (as shown at left) are used to show bundles of goods to which a person would assign equal utility . An isoquant (in the image at right) is a curve of equal production quantity for alternative combinations of input usages, and an isocost curve (also in the image at right) shows alternative usages having equal production costs . </P> <P> In political science an analogous method is used in understanding coalitions (for example the diagram in Laver and Shepsle's work). </P>

Isolines are used to represent equal barometric pressure on the earth's surface