Tab alignment in legend of Matplotlib Plot - matplotlib

I would like to create a plot with a legend aligning the text of the different curves. Here is a minimal working example:
import matplotlib.pyplot as plt
import numpy as np
x=np.linspace(0,10,100)
plt.plot(x,np.sin(x),'-',label=r'1st, second, third, a$_b$')
plt.plot(x,np.cos(x),'--',label=r'fourth, 5th, 5$_{fo}$, sixth')
plt.legend()
plt.show()
I want the labels to align in the legend, so get something like:
1st second third a$_b$
fourth 5th 5$_{fo}$ sixth
Is there a way of doing this?

An easy option would be to use a monospace font and fill the required space with blanks.
import matplotlib.pyplot as plt
import numpy as np
x=np.linspace(0,10,100)
plt.plot(x,np.sin(x),'-', label='1st second third a$_b$')
plt.plot(x,np.cos(x),'--',label='fourth 5th 5$_{fo}$ sixth')
plt.legend(prop={'family': 'DejaVu Sans Mono'})
plt.show()

Related

Is there a way to draw shapes on a python pandas plot

I am creating shot plots for NHL games and I have succeeded in making the plot, but I would like to draw the lines that you see on a hockey rink on it. I basically just want to draw two circles and two lines on the plot like this.
Let me know if this is possible/how I could do it
Pandas plot is in fact matplotlib plot, you can assign it to variable and modify it according to your needs ( add horizontal and vertical lines or shapes, text, etc)
# plot your data, but instead diplaying it assing Figure and Axis to variables
fig, ax = df.plot()
ax.vlines(x, ymin, ymax, colors='k', linestyles='solid') # adjust to your needs
plt.show()
working code sample
import pandas as pd
import matplotlib.pyplot as plt
import seaborn
from matplotlib.patches import Circle
from matplotlib.collections import PatchCollection
df = seaborn.load_dataset('tips')
ax = df.plot.scatter(x='total_bill', y='tip')
ax.vlines(x=40, ymin=0, ymax=20, colors='red')
patches = [Circle((50,10), radius=3)]
collection = PatchCollection(patches, alpha=0.4)
ax.add_collection(collection)
plt.show()

Can´t make violin chart appear in subplot

#Hi guys, I don´t know why the third plot below (violin) is not appearing in the third subplot space (it´s empty), could you pls assist?
#Code
import matplotlib.pyplot as plt
import seaborn as sns
fig, ax = plt.subplots(1,3)
fig.suptitle("Age Distribution", fontsize=15)
sns.distplot(insurance_ds["age"], ax=ax[0])
insurance_ds.boxplot(column=["age"], ax=ax[1])
sns.catplot(data=insurance_ds, kind="violin", y="age", ax=ax[2]) #->>>Not showing in third plot space
subplots
catplot() creates a new figure, and cannot be used to plot on a subplot.
You want to use sns.violinplot() directly.

Matplotlib: Get Rid of White Border

I want to get rid of the white border when I save my image to a png in python.
I tried plt.box(on=None), plt.axis('off'). I tried setting the figure's 'frameon' parameter to false.
import matplotlib.pyplot as plt
from matplotlib.pyplot import figure
figure(num=None, figsize=(7.965,7.965), dpi=80,facecolor='none',clear=True)
plt.box(on=None)
plt.axis('off')
plt.imshow(Data, cmap='Greys_r', norm=Norm,origin='lower',aspect='auto',interpolation='nearest')
plt.savefig(locationFITSfolder+fitsFile[:-5],transparent=False,bbox=False)
I want there to be no white border to my image. Transparent.
If you change the parameters to the savefig function, you will get the desired output.
Specifically, you must use transparent=True. Note that bbox=False and frameon=False are optional, and only change the width of transparent space around your image.
Adapting from your sample code:
import matplotlib.pyplot as plt
from matplotlib.pyplot import figure
#create sample data
import numpy as np
Data = np.random.random([4,4])
figure(num=None, figsize=(7.965,7.965), dpi=80,facecolor='none',clear=True)
plt.box(on=None)
plt.axis('off')
plt.imshow(Data, cmap='Greys_r',origin='lower',aspect='auto',interpolation='nearest')
plt.savefig(locationFITSfolder+fitsFile[:-5],transparent=True)
(sidenote -- you may wish to use os.path.join, .split, and .splitext for file I/O, instead of slicing string names)
This yields the expected image output: (note that the image has transparent borders when you open it in a new tab or download it).

python pandas plot line chart in pandas.plot hbar

I have a horizontal bar chart created with
df.plot(kind='barh', ax=ax)
and now I would like to plot a horizontal line chart in the same axis. How can I do that. There seems to be no equivalent lineh
I tried to just flip axes when plotting a regular line
df=pd.DataFrame(dict(k=['A','B','C','D'], v=[1,3,2,3]))
df.plot(x='v', y='k')
but then pandas complains that there is no numerical data to plot
If you want to use matplotlib, you can do like the following. Here the command xticks() is to set x-tick labels only at integer values.
import pandas as pd
import matplotlib.pyplot as plt
df=pd.DataFrame(dict(k=['A','B','C','D'], v=[1,3,2,3]))
plt.plot(df.v, df.k)
plt.xticks(range(1, max(df.v)+1))
plt.show()

customize the color of bar chart while reading from two different data frame in seaborn

I have plotted a bar chart using the code below:
dffinal['CI-noCI']='Cognitive Impairement'
nocidffinal['CI-noCI']='Non Cognitive Impairement'
res=pd.concat([dffinal,nocidffinal])
sns.barplot(x='6month',y='final-formula',data=res,hue='CI-noCI')
plt.xticks(fontsize=8, rotation=45)
plt.show()
the result is as below:
I want to change the color of them to red and green.
How can I do?
just as information, this plot is reading two different data frame.
the links I have gone through were with the case the dataframe was only one data frame so did not apply to my case.
Thanks :)
You can use matplotlib to overwrite Seaborn's default color cycling to ensure the hues it uses are red and green.
import matplotlib.pyplot as plt
plt.rcParams['axes.prop_cycle'] = ("cycler('color', 'rg')")
Example:
import seaborn as sns
import matplotlib.pyplot as plt
import pandas as pd
df = pd.DataFrame({'date': [1,2,3,4,4,5],
'value': [10,15,35,14,18,4],
'hue_v': [1,1,2,1,2,2]})
# The normal seaborn coloring is blue and orange
sns.barplot(x='date', y='value', data=df, hue='hue_v')
# Now change the color cycling and re-make the same plot:
plt.rcParams['axes.prop_cycle'] = ("cycler('color', 'rg')")
sns.barplot(x='date', y='value', data=df, hue='hue_v')
This will now impact all of the other figures you make, so if you want to restore the seaborn defaults for all other plots you need to then do:
sns.reset_orig()