Labels do not show

[aarondodell]

Labels are not showing on for igraph for some reason. I've included code below, which is almost line for line from the Tutorial.

import igraph as ig

g = ig.Graph([(0,1), (0,2), (2,3), (3,4), (4,2), (2,5), (5,0), (6,3), (5,6)])

g.vs["name"] = ["Alice", "Bob", "Claire", "Dennis", "Esther", "Frank", "George"]
g.vs["age"] = [25, 31, 18, 47, 22, 23, 50]
g.vs["gender"] = ["f", "m", "f", "m", "f", "m", "m"]
g.es["is_formal"] = [False, False, True, True, True, False, True, False, False]

layout = g.layout_kamada_kawai()

g.vs["label"] = g.vs["name"]
color_dict = {"m": "blue", "f": "pink"}
g.vs["color"] = [color_dict[gender] for gender in g.vs["gender"]]

ig.plot(g, layout = layout, bbox = (300, 300), margin = 20)

This code produces the following graph for me, which has everything except for the labels.

All of my igraph and Cairo should be up to date as well.

cairo.version
Out[3]: '1.17.1'

ig.__version__
Out[4]: '0.7.1+5.3b99dbf6'

I've also tried using keyword arguments to set the label, but that doesn't work either.

visual_style = {}
visual_style["vertex_size"] = 20
visual_style["vertex_color"] = [color_dict[gender] for gender in g.vs["gender"]]
visual_style["vertex_label"] = g.vs["name"]
visual_style["edge_width"] = [1 + 2 * int(is_formal) for is_formal in g.es["is_formal"]]
visual_style["layout"] = layout
visual_style["bbox"] = (300, 300)
visual_style["margin"] = 20
ig.plot(g, **visual_style)

I hope I've given you enough information to help, I cannot find anyone else with a Missing Labels issue.

[aarondodell]

My apologies, it looks like the Labels were not showing because I was graphing inline on iPython 6.4.0

Once I saved the file as an SVG, I was able to see the Labels.

I'll leave it up to your discretion on what to do with this issue since I'm sure other people have had this issue before, or if it even merits a fix.

[ntamas]

Hmmm, could it be an issue with missing fonts somehow?

When you use the write_svg() method, igraph constructs an SVG file "manually". For all other plotting methods (including inline plots in IPython), igraph uses the Cairo library installed on your machine to take care of producing the plot -- igraph simply instructs Cairo to use the default sans-serif font on your system and leaves it up to Cairo to work out the details. So, all in all, this could be a Cairo-specific issue that has nothing to do with igraph itself. It would be helpful to know which platform you are using and what version of IPython (although I can't promise that I'll have time to set up an environment identical to yours to reproduce the problem in the near future).

[roblem]

Also having this issue on Fedora 28 (in Anaconda python 3.6 Environment). Even using the write_svg() method results in no labels. Had to apply patch here to get inline images to show labels. Saved svg's still don't have them.

[ntamas]

Even using the write_svg() method results in no labels.

This is interesting; write_svg() does not use Cairo and constructs an SVG file manually (it is used as a fallback in environments where the user wants to plot but does not have Cairo). If the issue still persists, can you post an example SVG file created with write_svg() that shows no labels for you?

[aarondodell]

closing issue as no longer needed