Matplotlib barh capstyle 'round' not working? - python

I created a barh plot including xerr. For the caps of the errorbars I would like round edges. I tried to set the capstyle in the error_kw, which didn't work out.
bars = ax.barh(range(3), [1,2,3],
xerr=[0.5,0.4,0.3],
align='center', color='silver', height=0.5,
capsize=12, error_kw={'elinewidth':1, 'solid_capstyle':'round'})
I also tried to access the Line2D objects afterwards to change the capstyle, which also didn't work out.
bars.errorbar.lines[1][0].set_solid_capstyle('round')
Can someone please give me a hint what I'm doing wrong here?

I found the problem now, I had to access the private attribute of the cap. Instead of the method
cap.set_solid_capstyle('round')
I had to access the private attribute:
cap._marker._capstyle = "round"
Thanks for your comment anyway #tmdavison

Related

How to set gridlines behind boxplots in seaborn/matplotlib? [duplicate]

In Matplotlib, I make dashed grid lines as follows:
fig = pylab.figure()
ax = fig.add_subplot(1,1,1)
ax.yaxis.grid(color='gray', linestyle='dashed')
however, I can't find out how (or even if it is possible) to make the grid lines be drawn behind other graph elements, such as bars. Changing the order of adding the grid versus adding other elements makes no difference.
Is it possible to make it so that the grid lines appear behind everything else?
According to this - http://matplotlib.1069221.n5.nabble.com/axis-elements-and-zorder-td5346.html - you can use Axis.set_axisbelow(True)
(I am currently installing matplotlib for the first time, so have no idea if that's correct - I just found it by googling "matplotlib z order grid" - "z order" is typically used to describe this kind of thing (z being the axis "out of the page"))
To me, it was unclear how to apply andrew cooke's answer, so this is a complete solution based on that:
ax.set_axisbelow(True)
ax.yaxis.grid(color='gray', linestyle='dashed')
If you want to validate the setting for all figures, you may set
plt.rc('axes', axisbelow=True)
or
plt.rcParams['axes.axisbelow'] = True
It works for Matplotlib>=2.0.
I had the same problem and the following worked:
[line.set_zorder(3) for line in ax.lines]
fig.show() # to update
Increase 3to a higher value if it does not work.
You can also set the zorder kwarg in matplotlib.pyplot.grid
plt.grid(which='major', axis='y', zorder=-1.0)
You can try to use one of Seaborn's styles. For instance:
import seaborn as sns
sns.set_style("whitegrid")
Not only the gridlines will get behind but the looks are nicer.
For some (like me) it might be interesting to draw the grid behind only "some" of the other elements. For granular control of the draw order, you can use matplotlib.artist.Artist.set_zorder on the axes directly:
ax.yaxis.grid(color='gray', linestyle='dashed')
ax.set_zorder(3)
This is mentioned in the notes on matplotlib.axes.Axes.grid.

Adding multiple Pull Plots with matplot lib

I was working in a plot that had a pull plot, which I defined as :
fig, (ax1, ax2) = aplt.ratio_plot(name= canvasArray[kl], figsize=(800, 800), hspace=0.05)
and it was working fine, but now I have the need to add another pull plot in the image, so i tried:
fig, (ax1, ax2,ax3) = aplt.subplots(3,1,name="fig1", figsize=(850, 950))
and i got the resulting plot:
I tried some options like .set_aspect() but i keep getting the error AttributeError: 'Axes' object has no attribute 'set_aspect'. I would like that the main plot ocupy 2/4 of the full plot, and the pull plots 1/2 each, but i am having dificulties with that.
I am working in a object oriented enviroment, so i dont know if that changes things. I am using the Atlasplots package which uses matplotlib syntax. https://atlas-plots.readthedocs.io/en/latest/
I had an idea. Matplotlib.pyplot has a collection of parameters, and one of them controls the size of the plots. It is called: rcParams. This attribute internally is a dictionary that contains a lot of configurations. Take a look:
>>> from matplotlib import pyplot as plt
>>> plt.rcParams
If you run the above lines of code you get the following. Yeah, those are a lot of things, but we have one specific key that may solve our problem. It is "figure.figsize", if you select this parameter like this:
>>> plt.rcParams["figure.figsize"] = [6.0, 4.0]
You can customize the plot sizes. So I think you would be able to use this at certain locations in your code and reset it to the default values when needed.
To see what are the default values, just run this to get the output based on the key "figure.figsize":
>>> plt.rcParams["figure.figsize"]
[out]: ["your default", "values here"]
Update: October 1, 2021
I've just remembered that you can also unpack subplots (matplotlib.pyplot.subplots) and select directly the parameters, like this:
>>> fig, ax = plt.subplots(figsize=("the size", "you want"))
I've also noticed something very interesting. If you use rcParams["figure.figsize"] to control plot size, it will be persistent throughout the code, but if you use the option shown in the update, the configuration will apply only to that plot area. That is a behavior that I've observed here.

Show text annotations on selection in Bokeh

I have a little Bokeh plot with data points and associated text labels. What I want is for the text labels to only appear when the user selects points with the box select tool. This gets me close:
from bokeh.plotting import ColumnDataSource,figure,show
source = ColumnDataSource(
data=dict(
x=test[:,0],
y=test[:,1],
label=[unquote_plus(vocab_idx[i]) for i in range(len(test))]))
TOOLS="box_zoom,pan,reset,box_select"
p = figure(plot_width=400, plot_height=400,tools=TOOLS)
p.circle(x='x',y='y', size=10, color="red", alpha=0.25,source=source)
renderer = p.text(x='x',y='y',text='label',source=source)
renderer.nonselection_glyph.text_alpha=0.
show(p)
This is close, in that if I draw a box around some points, those text labels are shown and the rest are hidden, but the problem is that it renders all the text labels to start (which is not what I want). The initial plot should have all labels hidden, and they should only appear upon a box_select.
I thought I could start by rendering everything with alpha=0.0, and then setting a selection_glyph parameter, like this:
...
renderer = p.text(x='x',y='y',text='label',source=source,alpha=0.)
renderer.nonselection_glyph.text_alpha=0.
renderer.selection_glyph.text_alpha=1.
...
But this throws an error:
AttributeError: 'NoneType' object has no attribute 'text_alpha'
When trying to access the text_alpha attribute of selection_glyph.
I know I could use a hover effect here or similar, but need the labels to default to not being visible. An alternative, but not ideal, solution would be to have a toggle button that switches the labels on and off, but I'm not sure how to do that either.
What am I doing wrong here?
As of version 0.11.1, the value of selection_glyph is None by default. This is interpreted by BokehJS as "don't do anything different, just draw the glyph as normal". So you need to actually create a selection_glyph. There are two ways to do this, both demonstrated here:
http://docs.bokeh.org/en/latest/docs/user_guide/styling.html#selected-and-unselected-glyphs
Basically, they are
by hand
Create an actual Circle Bokeh model, something like:
selected_circle = Circle(fill_alpha=1, fill_color="firebrick", line_color=None)
renderer.selection_glyph = selected_circle
OR
using glyph method parameters
Alternatively, as a convenience Figure.circle accepts paramters like selection_fill_alpha or selection_color (basically any line or fill or text property, prefixed with selection_) :
p.circle(..., selection_color="firebrick")
Then a Circle will be created automatically and used for renderer.selection_glyph
I hope this is useful information. If so, it highlights that there are two possible ways that the project could be improved:
updating the docs to be explicit and highlight that renderer.selection_glyph is None by default
changing code so that renderer.selection_glyph is just a copy of renderer.glyph by default (then your original code would work)
Either would be small in scope and ideal for a new contributor. If you would be interested in working up a Pull Request to do either of these tasks, we (and other users) would certainly be grateful for the contribution. In which case, please just make an issue first at
https://github.com/bokeh/bokeh/issues
that references this discussion, and we can provide more details or answer any questions.

Using matplotlib, how do I whiten the background of the axis label?

Is there a way to whiten out the background of the axis label so that when it crosses the axis line itself, the latter does not run through it?
For example, this script (the best I managed so far)
#!/usr/bin/python
import matplotlib.pyplot as plt
xx=[1,2,3]
yy=[2,3,4]
dy=[0.1,0.2,0.05]
fig=plt.figure()
ax=fig.add_subplot(111)
ax.errorbar(xx,yy,dy,fmt='ro-',ms=6,elinewidth=4)
ax.set_xlim([0.,3.4])
ax.set_ylim([0.,4.4])
ax.set_xlabel(r'$T/t$',fontsize=16)
ax.set_ylabel(r'$S(\mathbf{Q})L^{1+\eta}$',fontsize=16)
# position the axis labels
ax.xaxis.set_label_coords(1,0)
ax.yaxis.set_label_coords(0.1,0.93)
ax.yaxis.get_label().set_rotation('horizontal')
ax.yaxis.get_label().set_backgroundcolor('w')
#ax.yaxis.get_label().set_zorder(222) #doesn't do the trick
plt.show()
produces almost what I'm looking for, but still the y-axis runs over the label: .
By default, the left spine has a zorder of 2.5. For some reason this seems to cause problems; maybe there's something in the code which only works if they're integral? Anyway, if you add
ax.spines['left'].set_zorder(2)
or more generally
ax.spines['left'].set_zorder(ax.yaxis.get_label().get_zorder()-1)
before the show, it should work. Also, set_ylabel returns the ylab object itself, so if you use "ylab = ax.set_ylabel(stuff)" you can avoid all the ax.yaxis.get_label() calls later.
Does this link help you?
http://matplotlib.sourceforge.net/faq/howto_faq.html#automatically-make-room-for-tick-labels
You can simply shift the y-axis to the right to allows some space for the $S(\mathbf{Q})L^{1+\eta}$ mark be fully placed before the axis line.

Matplotlib: draw grid lines behind other graph elements

In Matplotlib, I make dashed grid lines as follows:
fig = pylab.figure()
ax = fig.add_subplot(1,1,1)
ax.yaxis.grid(color='gray', linestyle='dashed')
however, I can't find out how (or even if it is possible) to make the grid lines be drawn behind other graph elements, such as bars. Changing the order of adding the grid versus adding other elements makes no difference.
Is it possible to make it so that the grid lines appear behind everything else?
According to this - http://matplotlib.1069221.n5.nabble.com/axis-elements-and-zorder-td5346.html - you can use Axis.set_axisbelow(True)
(I am currently installing matplotlib for the first time, so have no idea if that's correct - I just found it by googling "matplotlib z order grid" - "z order" is typically used to describe this kind of thing (z being the axis "out of the page"))
To me, it was unclear how to apply andrew cooke's answer, so this is a complete solution based on that:
ax.set_axisbelow(True)
ax.yaxis.grid(color='gray', linestyle='dashed')
If you want to validate the setting for all figures, you may set
plt.rc('axes', axisbelow=True)
or
plt.rcParams['axes.axisbelow'] = True
It works for Matplotlib>=2.0.
I had the same problem and the following worked:
[line.set_zorder(3) for line in ax.lines]
fig.show() # to update
Increase 3to a higher value if it does not work.
You can also set the zorder kwarg in matplotlib.pyplot.grid
plt.grid(which='major', axis='y', zorder=-1.0)
You can try to use one of Seaborn's styles. For instance:
import seaborn as sns
sns.set_style("whitegrid")
Not only the gridlines will get behind but the looks are nicer.
For some (like me) it might be interesting to draw the grid behind only "some" of the other elements. For granular control of the draw order, you can use matplotlib.artist.Artist.set_zorder on the axes directly:
ax.yaxis.grid(color='gray', linestyle='dashed')
ax.set_zorder(3)
This is mentioned in the notes on matplotlib.axes.Axes.grid.

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