# Set Functions

Allows you to do set functions on gene sets(union, intersection, and symmetric difference). Choose groups and use the pulldown Analysis menu to select which function you would like.

## Union

The `Union`

operation allows you to combine two or more gene
sets into a new set consisting of all of the genes in those sets. The
union operation does not add the same gene more than once to the new
set; as a result, the sum of the number of genes in the original sets
may be greater than the number of genes in the union.

## Intersect

Figure 1: Intersect
The `Interesect`

operation gives you those genes
shared by all selected sets. Only those genes shared by the selected
sets will appear in the new set. Figure 1 shows a Venn diagram
illustrating the component that appears in the Intersect.

## Symmetric Difference

Figure 2:
Symmetric Difference
The symmetric difference is the union of the sets minus the intersect.
It represents those genes that only appear in one of the
selected sets, and do not appear in any other. An example
Venn diagram is shown in Figure 2.