EdgeR: Heatmaps

[polsum]

Hi, I know DESeq can make some really nice heat maps along with clustering of the differentially expressed genes. How can I make such maps with edger? Can I import edgeR data to Deseq to make those graphs?

Thanks in advance.

[chadn737]

The commands used to make heatmaps in the DESeq vignette are not part of the DESeq package. You can make them easily enough in R using any data. You will just have to modify them to recognize the appropriate fields in EdgeR.

[Simon Anders]

However, what is part of DESeq is the function 'getVarianceStabilizedData' that transforms the data to a scale suitable as input to clustering or heatmap functions.

[gringer]

However, what is part of DESeq is the function 'getVarianceStabilizedData' that transforms the data to a scale suitable as input to clustering or heatmap functions.

would it be reasonable to filter out transcripts / genes that have low read counts prior to doing this clustering (e.g. fewer than 5 reads in all samples, or fewer than 50 reads in any sample)? Alternaltively, will clustering with the variance-stabilized data work better if you use only the most expressed transcripts (e.g. top 1000, based on rowSums)?

[Simon Anders]

That depends a lot on what you hope to achieve with the clustering. A classical application is to see similarity of samples; and in that case you would not want to restrict yourself to only the most strongly expressed genes. However, as clustering with all genes is often computationally to expensive, it may help to kick out low-variance genes, which have the same value in all samples and so help little to distinguish them.

[polsum]

However, what is part of DESeq is the function 'getVarianceStabilizedData' that transforms the data to a scale suitable as input to clustering or heatmap functions.

Simon, this precisely is my question. The function 'getVarianceStabilizedData' uses 'cds' as the argument which doesnt have same structure as argument 'd' generated by EdgeR. My question is how to give 'd' as the argument to this function?

Sorry, I am very naive to 'R' language.

Thanks