textcords='axes fraction' does not work for some axes ranges

[tacaswell]

For some axes ranges, annotations will not be drawn

ax = gca()
ax.set_ylim([0,.3])
ax.annotate('.5',(.1,.5),textcoords='axes fraction' ,weight='bold',fontsize=14 )
ax.annotate('.1',(.1,.1),textcoords='axes fraction' ,weight='bold',fontsize=14 )
draw() # only .1 will show up
ax.set_ylxm([0,3])
draw() # both will show up

May be related to issues #1310 and #403

In [17]: matplotlib.version
Out[17]: '1.2.0rc2'

QT4Agg with PyQT4

edited to add links

[WeatherGod]

Confirmed... that is really weird.

at ax.set_ylim([0, .4993630573]), is the highest value at which the annotation does not appear (at least, at that many decimal places). I did not bother doing more.

[mdf-github]

I have a similar issue with the 'axes fraction' and 'figure fraction' when using annotate() in log-log plots. The annotations disappear when the log scales are introduced, but they're fine when using regular scales.

Here's a sample of my code.

plt.clf()
samplevalues = [100,1000,5000,10^4]
ax = plt.subplot(111)
ax.plot(samplevalues,samplevalues,'o',color='black')
ax.annotate('hi',(0.5,0.5), textcoords='axes fraction')
ax.set_xscale('log')
ax.set_yscale('log')
plt.show()

I'm using matplotlib 0.99.3. Commenting out the set_xcale('log') parts will make the annotation appear. Thanks @tacaswell for alerting me to this bug!

[cimarronm]

I don't think the original issue is a bug. The problem with the example code is that the xy cooridantes (not text coordinates) are given but textcoords are specified as axes fraction instead of xycoords. If you specify it as xycoords='axes fraction' then it works as expected and I would argue is the proper functionality.

ax = gca()
ax.set_ylim([0,.3])
ax.annotate('.5',(.1,.5),xycoords='axes fraction' ,weight='bold',fontsize=14 )
ax.annotate('.1',(.1,.1),xycoords='axes fraction' ,weight='bold',fontsize=14 )
draw() # both show up

[cimarronm]

As for the second example, the same holds true, and is not a bug. If you replace with xycoords it shows the intended behavior.

plt.clf()
samplevalues = [100,1000,5000,10^4]
ax = plt.subplot(111)
ax.plot(samplevalues,samplevalues,'o',color='black')
ax.annotate('hi',(0.5,0.5), xycoords='axes fraction')
ax.set_xscale('log')
ax.set_yscale('log')
plt.show()

The main misunderstanding here is that there are two xy points in an annotation: 1) a data point being annotated (xy which xycoords specifies the units) and 2) an optional text coordinates (xytext which textcoords specifies the units).

[tacaswell]

Well, that is embarrassing....

Looking at this again, what is going on in my OP is that the annotation is the equivalent of ax.annotate('.5',xy=(.1,.5), xytext=(1, .5), textcoords='axes fraction' , xycoords='data') which decides that the annotation does not need to get drawn if the point being marked falls outside of the viewing window, which seems like the correct behavior.

There probably should be a warning if the user sets textcoords but not xytext.