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code from blog post to make a volcano plot
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| # Download the data from github (click the "raw" button, save as a text file called "results.txt"). | |
| # https://gist.github.com/stephenturner/806e31fce55a8b7175af | |
| res <- read.table("results.txt", header=TRUE) | |
| head(res) | |
| # Make a basic volcano plot | |
| with(res, plot(log2FoldChange, -log10(pvalue), pch=20, main="Volcano plot", xlim=c(-2.5,2))) | |
| # Add colored points: red if padj<0.05, orange of log2FC>1, green if both) | |
| with(subset(res, padj<.05 ), points(log2FoldChange, -log10(pvalue), pch=20, col="red")) | |
| with(subset(res, abs(log2FoldChange)>1), points(log2FoldChange, -log10(pvalue), pch=20, col="orange")) | |
| with(subset(res, padj<.05 & abs(log2FoldChange)>1), points(log2FoldChange, -log10(pvalue), pch=20, col="green")) | |
| # Label points with the textxy function from the calibrate plot | |
| library(calibrate) | |
| with(subset(res, padj<.05 & abs(log2FoldChange)>1), textxy(log2FoldChange, -log10(pvalue), labs=Gene, cex=.8)) |
Thanks
When labeling points, is there a way to keep the labels from overlapping?
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Hello! I have a problem in highlighting the significant genes. When I am using your data set, everything goes fine. But when I am trying with my data set I color the whole volcano plot red/orange. I have named everything exactly as here but still doesn't work. I checked my data set and it does contain genes with p.adj.values<.05. Do you have any idea why is this happening?
Btw we have tried with both csv and txt files, with two different computers, two different people but always the same annoying result!