# [R] for each element in matrix...

From: Andrej Kastrin <andrej.kastrin_at_siol.net>
Date: Mon 06 Feb 2006 - 07:21:20 EST

I wrote function, which plot dotchart from given matrix, compute mean from diagonal elements and plot it with abline. In addition, if particular element of matrix is greater then mean value (i.e. mead.diagonal), it should be plot in red, otherwise in green color.

graph <- function(a) {

```    rownames(a) <- 1:nrow(a)
colnames(a) <- 1:ncol(a)
mean.diagonal <- mean(a[row(a) == col(a)])
```
par(bg = "gray95")
dotchart(a, cex = 0.9, main = "MeSH Plot", xlab = "frequency",
```        bg = ifelse((a) > mean.diagonal,"red", "green2"),  # !!!
pch = 21,labels = rownames(a))
```
abline(v = mean.diagonal, col = "red", lty = 4) }

And now the main problem: I suppose that there is some mismatch in ifelse statement while I produce two totally different plots: first input matrix: A <-matrix(rep(c(1,3,4),3),3,3) # seem that works second input matrix B <-matrix(rnorm(9),3,3) # total confusion between green and red points