rotating plot layout

Usage
1

I figured out that I can rotate a Plot by accessing an undocumented API:

import igraph as ig

g = ig.Graph.Bipartite([0, 0, 0, 0, 0, 0, 1, 1, 1, 1], 
                       [(0, 6), (1, 6), (2, 7), (3, 8), (4, 9), (5, 6)])
plot = ig.plot(g, layout=g.layout_bipartite(), vertex_label=list('ABCDEFwxyz'))
# -> plot is vertical

# access Layout object and call its rotate method
plot._objects[0][-1]["layout"].rotate(90)
# -> plot is now horizontal!

Any chance we can expose this ability to manipulate the layout through a stable API? And maybe we can even make horizontal orientation the default for the bipartite layout?

2

I figured out that the following works:

lo = g.layout_bipartite()
lo.rotate(90)
plot = ig.plot(g, layout=lo, vertex_label=list('ABCDEFwxyz'))

The important thing is that the rotation has to happen in a separate step, because the .rotate method returns None.

3

Yes, indeed, the rotation happens “in place”, so to speak. You would find it more intuitive if you could concatenate the steps like g.layout_bipartite().rotate(90).mirror() for example?

Do note that the functionality is documented here.

1 Like
4

You would find it more intuitive if you could concatenate the steps like g.layout_bipartite().rotate(90).mirror() for example?

That’s what I tried initially, so yes, I suppose it would be more intuitive to be able to chain methods like that. Though I am familiar with the convention of returning None for such in-place mutations of objects in Python.

Do note that the functionality is documented

Thanks, I found that eventually. It’s not linked to from the API reference for Plot which is why I missed it at first.

5

thanks for the awesome information.

6

thanks my issue has been fixed.