search for: microlitres

I have a small problem with R graphics output. When I use the lattice package and CairoPDF to generate publication quality graphs I often use the expression to create an axis title that has microlitres or micrometers as a unit. I use something like the following 'expression(paste("Length (", mu,"m )"))' as an argument to the xlabel function. The command works but the mu and 'm' have a space between them. It looks like 'u m' rather than 'um'. It...