support xflip and yflip for heatmaps

[fredcallaway]

In particular, yflip would be really nice because this is the orientation in which matrices are printed.

[t-bltg]

Are you looking for the array keyword ?

help?> heatmap
[...]
    •  array : use array display convention (origin at the North-West
       corner of the plot, hence flipping y versus regular plots).

[fredcallaway]

I guess I was—although I still adding yflip as a synonym would make sense for consistency with the rest of the package (and Plots.jl)

[t-bltg]

Yeah, I don't remember why array was added, especially since xflip and yflip seem to be supported natively by heatmap and the underlying canvas.

[t-bltg]

Can I close this issue since yflip is working as expected here, e.g. heatmap(reshape(1:6^2, 6, 6), yflip=true) ?

[fredcallaway]

I'm so sorry—I have no idea how I managed to convince myself that yflip wasn't supported.