R - change size of axis labels for corrplot

Question

I am using the following with corrplot:

require("corrplot") ## needs the corrplot package
corrplot(cor(lpp_axis1, lpp_axis2), method=c("number"), bg = "grey10",
         addgrid.col = "gray50", tl.offset = 2, tl.cex=2,
         tl.col = "black", 
         col = colorRampPalette(c("yellow","green","navyblue"))(100))

This is created with a csv file available here.

The graph is fine and I can adjust the cl labels all I want. I've tried adjusting the labels on x and y axis with no impact. I looked at changing mar - yet I haven't found a way to. I was unsuccessful with trying to use cex.label to change size.

The question - how can I make the text appearing for corrplot (not the cl, and not in the grid) larger?

The two axes are the following data frames:

lpp_axis1 <- data.frame("Compile Source Code" = Q3A.1, "View Source Code" = Q3A.2, "Change Source Code" = Q3A.3, "Write Documentation" = Q3A.8, "File Bug Reports"= Q3B.3, "Ask Questions" = Q3B.5, "Provide Answers" = Q3B.6, "Overall Participation" = Q3a3bConsolidated)

lpp_axis2 <- data.frame("Identification" = Q1,"Overall Learning" = Q6Consolidated,  "Learning Programming" = Q6.1,  "Learning about Computers" = Q6.2, "Learning Teamwork" =  Q6.3)

The output from

str(lpp_axis1)

is

> str(lpp_axis1)
'data.frame':   4603 obs. of  8 variables:
 $ Compile.Source.Code  : int  4 2 3 2 2 2 3 2 2 0 ...
 $ View.Source.Code     : int  4 2 1 1 2 2 3 1 1 0 ...
 $ Change.Source.Code   : int  4 1 0 1 2 1 2 1 1 0 ...
 $ Write.Documentation  : int  4 1 2 2 3 0 3 0 1 0 ...
 $ File.Bug.Reports     : int  4 4 1 2 2 0 2 0 0 0 ...
 $ Ask.Questions        : int  4 4 2 4 2 1 2 1 3 0 ...
 $ Provide.Answers      : int  2 4 1 4 4 0 3 1 3 0 ...
 $ Overall.Participation: int  49 26 14 32 31 8 27 10 15 0 ...

The output from

packageDescription("corrplot")

indicates:

Package: corrplot
Type: Package
Title: visualization of a correlation matrix
Version: 0.30
Date: 2010-05-30
Author: Taiyun Wei
Suggests: seriation, cairoDevice, Cairo,
Maintainer: Taiyun Wei <[email protected]>
Description: The corrplot package is a graphical display of a
        correlation matrix, confidence interval. It also contains some
        algorithms to do matrix reordering.
License: GPL-2 | GPL-3
LazyLoad: yes
URL: http://corrplot.r-forge.r-project.org
Repository: CRAN
Repository/R-Forge/Project: corrplot
Repository/R-Forge/Revision: 45
Date/Publication: 2010-05-31 07:44:14
Packaged: 2010-05-30 20:39:16 UTC; rforge
Built: R 2.11.1; ; 2011-03-19 00:22:49 UTC; unix

-- File: /home/user/R/x86_64-pc-linux-gnu-library/2.11/corrplot/Meta/package.rds 
> 

The corrplot maintainer wrote back with an alternate corrplot.r available here

Using the this corrplot and the example code below, the text size is acceptable. However, attempts to increase it also produce the same effects.

source("http://misterdavis.org/R_info/corrplot.r")
corrplot(cor(lpp_axis1, lpp_axis2), addn=T,
         addgrid.col = "gray50", tl.cex=2, assign.col="min2max",
         tl.col = "black", cl.ratio=0.4, addcolor="no",
         col = colorRampPalette(c("yellow","green","blue"))(100))

Using an earlier version of the correlation circles available here, it is possible to adjust the text to one's heart desire. (Though the graph lacks some of the functionality of the later, more refined corrplot package.) cex can be used for cex. I may try to tweak the two to come up with a happy medium as time permits.

Using the older correlation circles script, the following code produces sufficiently large X and Y axis labels:

circle.corr(cor(lpp_axis1, lpp_axis2), bg = "gray50",   col = colorRampPalette(c("navyblue","white", "red"))(100), cex=1.5)

Answer 1

You could try changing the point size of text with par. I think the default size is 12.
Adding a line like par( ps=14) before corrplot should make the text larger.