R pairs function - How to change the diagonal values font size?

Question

I have a pairs function in R which is plotting a graphic but the font size is bigger than I would like. Is there any way to reduce it?

Update:

My pairs function:

pairs(~erro_O3_s+erro_NO2_s+O3_ref+NO2_ref, data=person.data,
      upper.panel=panel.regression, lower.panel=panel.cor, 
      pch=20)

I can change the font size with cex but not the diagonals font size.

Answer 1

cex.labels changes the diagonal font size.

Using the functions from your previous question: try pairs(mtcars[1:3], upper.panel=panel.regression, lower.panel=panel.cor, cex.labels=1)

and pairs(mtcars[1:3], upper.panel=panel.regression, lower.panel=panel.cor, cex.labels=10)