InteractGraph: functions to visualize interactions as a graph
In coRNAi: Analysis of co-knock-down RNAi data

visualizes significant interactions as a graph

1	InteractGraph(toptable,thresh,sizecutoff=0,by,key=FALSE,file="interactions",colors = list(neg="blue",pos="yellow",key="brown",node="grey"))

`toptable`	`toptable` table from function topTable
`thresh`	`thresh` numeric, threshold for significance
`sizecutoff`	`sizecutoff` a minimal absolute size of a interaction for it to be included in the graph as an edge.
`by`	`by` column in topTable that thresh should be applied to
`key`	`key` optional, data frame with groupings of the genes in the toptable
`file`	`file` name of the file the results will be outputed to.
`colors`	`colors` list with colors to be used for pos interactions, neg interactions, key (nodes in key) and normal nodes.