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plot(1:5, xlim = c(0, 6), ylim = c(0,6), 
     xaxt = 'n', yaxt = 'n',
     xlab = 'xlab cex = 1.2', ylab = 'ylab cex = 1.2',
     cex.lab = 1.2,
     main = 'Main title cex = 2', cex.main = 2,
     sub = 'subtitle cex = 0.5', cex.sub = 0.5)
axis(side=1, at=1:5, labels = rep('cex=0.5', 5), cex.axis = 0.5)
axis(side=2, at=1:5, labels = rep('cex=0.5', 5), cex.axis = 0.5)
labels = paste0('cex=', (1:5)/10)
text(x=1:5, y=1:5 + 0.5, labels = labels, 
     cex = (1:5)/10, family = "serif")