Theme interface for ggpairs subplots #569
Description
Hi, I'm enjoying the ggpairs() function, however one bothersome point is that if I want to change the theme for one set of subplots (vs all subplots) I have recreate the whole plot and append the theme. To change the whole plot, you can of course simply do ggpairs() + theme_bw() or whatever. But for example, with the correlation plots this doesn't make sense as it adds grid lines. To get around this, I've been doing things like:
diag = list(continuous = \(data,mapping,...) ggplot(data,mapping)+geom_density(...)+theme_classic() )
But of course it's a bit of a bother trying to recreate all the subplots, especially the more complex ones. I would have to guess that adjusting the theme is the most common modification people want to make to the subplots, so a simplified interface would be very convenient. So as a suggestion/feature request, could you add a theme interface for the upper/lower/diag plots? Perhaps within the upper/lower/diag lists you could accept a 'theme' argument that updates the plot theme? Then the above syntax could be simplified to:
diag = list(theme = 'classic')
That would be really nice. Thanks!