Common X and Y axis lable for all subplots in the case of sns.lineplot and axhline? [duplicate] - python-3.x

I have the following plot:
import matplotlib.pyplot as plt
fig2 = plt.figure()
ax3 = fig2.add_subplot(2,1,1)
ax4 = fig2.add_subplot(2,1,2)
ax4.loglog(x1, y1)
ax3.loglog(x2, y2)
ax3.set_ylabel('hello')
I want to be able to create axes labels and titles not just for each of the two subplots, but also common labels that span both subplots. For example, since both plots have identical axes, I only need one set of x and y- axes labels. I do want different titles for each subplot though.
I tried a few things but none of them worked right

You can create a big subplot that covers the two subplots and then set the common labels.
import random
import matplotlib.pyplot as plt
x = range(1, 101)
y1 = [random.randint(1, 100) for _ in range(len(x))]
y2 = [random.randint(1, 100) for _ in range(len(x))]
fig = plt.figure()
ax = fig.add_subplot(111) # The big subplot
ax1 = fig.add_subplot(211)
ax2 = fig.add_subplot(212)
# Turn off axis lines and ticks of the big subplot
ax.spines['top'].set_color('none')
ax.spines['bottom'].set_color('none')
ax.spines['left'].set_color('none')
ax.spines['right'].set_color('none')
ax.tick_params(labelcolor='w', top=False, bottom=False, left=False, right=False)
ax1.loglog(x, y1)
ax2.loglog(x, y2)
# Set common labels
ax.set_xlabel('common xlabel')
ax.set_ylabel('common ylabel')
ax1.set_title('ax1 title')
ax2.set_title('ax2 title')
plt.savefig('common_labels.png', dpi=300)
Another way is using fig.text() to set the locations of the common labels directly.
import random
import matplotlib.pyplot as plt
x = range(1, 101)
y1 = [random.randint(1, 100) for _ in range(len(x))]
y2 = [random.randint(1, 100) for _ in range(len(x))]
fig = plt.figure()
ax1 = fig.add_subplot(211)
ax2 = fig.add_subplot(212)
ax1.loglog(x, y1)
ax2.loglog(x, y2)
# Set common labels
fig.text(0.5, 0.04, 'common xlabel', ha='center', va='center')
fig.text(0.06, 0.5, 'common ylabel', ha='center', va='center', rotation='vertical')
ax1.set_title('ax1 title')
ax2.set_title('ax2 title')
plt.savefig('common_labels_text.png', dpi=300)

One simple way using subplots:
import matplotlib.pyplot as plt
fig, axes = plt.subplots(3, 4, sharex=True, sharey=True)
# add a big axes, hide frame
fig.add_subplot(111, frameon=False)
# hide tick and tick label of the big axes
plt.tick_params(labelcolor='none', top=False, bottom=False, left=False, right=False)
plt.grid(False)
plt.xlabel("common X")
plt.ylabel("common Y")

New in matplotlib 3.4.0
There are now built-in methods to set common axis labels:
supxlabel
fig.supxlabel('common x label')
supylabel
fig.supylabel('common y label')
To reproduce OP's loglog plots (common labels but separate titles):
x = np.arange(0.01, 10.01, 0.01)
y = 2 ** x
fig, (ax1, ax2) = plt.subplots(2, 1, constrained_layout=True)
ax1.loglog(y, x)
ax2.loglog(x, y)
# separate subplot titles
ax1.set_title('ax1.title')
ax2.set_title('ax2.title')
# common axis labels
fig.supxlabel('fig.supxlabel')
fig.supylabel('fig.supylabel')

plt.setp() will do the job:
# plot something
fig, axs = plt.subplots(3,3, figsize=(15, 8), sharex=True, sharey=True)
for i, ax in enumerate(axs.flat):
ax.scatter(*np.random.normal(size=(2,200)))
ax.set_title(f'Title {i}')
# set labels
plt.setp(axs[-1, :], xlabel='x axis label')
plt.setp(axs[:, 0], ylabel='y axis label')

Wen-wei Liao's answer is good if you are not trying to export vector graphics or that you have set up your matplotlib backends to ignore colorless axes; otherwise the hidden axes would show up in the exported graphic.
My answer suplabel here is similar to the fig.suptitle which uses the fig.text function. Therefore there is no axes artist being created and made colorless.
However, if you try to call it multiple times you will get text added on top of each other (as fig.suptitle does too). Wen-wei Liao's answer doesn't, because fig.add_subplot(111) will return the same Axes object if it is already created.
My function can also be called after the plots have been created.
def suplabel(axis,label,label_prop=None,
labelpad=5,
ha='center',va='center'):
''' Add super ylabel or xlabel to the figure
Similar to matplotlib.suptitle
axis - string: "x" or "y"
label - string
label_prop - keyword dictionary for Text
labelpad - padding from the axis (default: 5)
ha - horizontal alignment (default: "center")
va - vertical alignment (default: "center")
'''
fig = pylab.gcf()
xmin = []
ymin = []
for ax in fig.axes:
xmin.append(ax.get_position().xmin)
ymin.append(ax.get_position().ymin)
xmin,ymin = min(xmin),min(ymin)
dpi = fig.dpi
if axis.lower() == "y":
rotation=90.
x = xmin-float(labelpad)/dpi
y = 0.5
elif axis.lower() == 'x':
rotation = 0.
x = 0.5
y = ymin - float(labelpad)/dpi
else:
raise Exception("Unexpected axis: x or y")
if label_prop is None:
label_prop = dict()
pylab.text(x,y,label,rotation=rotation,
transform=fig.transFigure,
ha=ha,va=va,
**label_prop)

Here is a solution where you set the ylabel of one of the plots and adjust the position of it so it is centered vertically. This way you avoid problems mentioned by KYC.
import numpy as np
import matplotlib.pyplot as plt
def set_shared_ylabel(a, ylabel, labelpad = 0.01):
"""Set a y label shared by multiple axes
Parameters
----------
a: list of axes
ylabel: string
labelpad: float
Sets the padding between ticklabels and axis label"""
f = a[0].get_figure()
f.canvas.draw() #sets f.canvas.renderer needed below
# get the center position for all plots
top = a[0].get_position().y1
bottom = a[-1].get_position().y0
# get the coordinates of the left side of the tick labels
x0 = 1
for at in a:
at.set_ylabel('') # just to make sure we don't and up with multiple labels
bboxes, _ = at.yaxis.get_ticklabel_extents(f.canvas.renderer)
bboxes = bboxes.inverse_transformed(f.transFigure)
xt = bboxes.x0
if xt < x0:
x0 = xt
tick_label_left = x0
# set position of label
a[-1].set_ylabel(ylabel)
a[-1].yaxis.set_label_coords(tick_label_left - labelpad,(bottom + top)/2, transform=f.transFigure)
length = 100
x = np.linspace(0,100, length)
y1 = np.random.random(length) * 1000
y2 = np.random.random(length)
f,a = plt.subplots(2, sharex=True, gridspec_kw={'hspace':0})
a[0].plot(x, y1)
a[1].plot(x, y2)
set_shared_ylabel(a, 'shared y label (a. u.)')

# list loss and acc are your data
fig = plt.figure()
ax1 = fig.add_subplot(121)
ax2 = fig.add_subplot(122)
ax1.plot(iteration1, loss)
ax2.plot(iteration2, acc)
ax1.set_title('Training Loss')
ax2.set_title('Training Accuracy')
ax1.set_xlabel('Iteration')
ax1.set_ylabel('Loss')
ax2.set_xlabel('Iteration')
ax2.set_ylabel('Accuracy')

The methods in the other answers will not work properly when the yticks are large. The ylabel will either overlap with ticks, be clipped on the left or completely invisible/outside of the figure.
I've modified Hagne's answer so it works with more than 1 column of subplots, for both xlabel and ylabel, and it shifts the plot to keep the ylabel visible in the figure.
def set_shared_ylabel(a, xlabel, ylabel, labelpad = 0.01, figleftpad=0.05):
"""Set a y label shared by multiple axes
Parameters
----------
a: list of axes
ylabel: string
labelpad: float
Sets the padding between ticklabels and axis label"""
f = a[0,0].get_figure()
f.canvas.draw() #sets f.canvas.renderer needed below
# get the center position for all plots
top = a[0,0].get_position().y1
bottom = a[-1,-1].get_position().y0
# get the coordinates of the left side of the tick labels
x0 = 1
x1 = 1
for at_row in a:
at = at_row[0]
at.set_ylabel('') # just to make sure we don't and up with multiple labels
bboxes, _ = at.yaxis.get_ticklabel_extents(f.canvas.renderer)
bboxes = bboxes.inverse_transformed(f.transFigure)
xt = bboxes.x0
if xt < x0:
x0 = xt
x1 = bboxes.x1
tick_label_left = x0
# shrink plot on left to prevent ylabel clipping
# (x1 - tick_label_left) is the x coordinate of right end of tick label,
# basically how much padding is needed to fit tick labels in the figure
# figleftpad is additional padding to fit the ylabel
plt.subplots_adjust(left=(x1 - tick_label_left) + figleftpad)
# set position of label,
# note that (figleftpad-labelpad) refers to the middle of the ylabel
a[-1,-1].set_ylabel(ylabel)
a[-1,-1].yaxis.set_label_coords(figleftpad-labelpad,(bottom + top)/2, transform=f.transFigure)
# set xlabel
y0 = 1
for at in axes[-1]:
at.set_xlabel('') # just to make sure we don't and up with multiple labels
bboxes, _ = at.xaxis.get_ticklabel_extents(fig.canvas.renderer)
bboxes = bboxes.inverse_transformed(fig.transFigure)
yt = bboxes.y0
if yt < y0:
y0 = yt
tick_label_bottom = y0
axes[-1, -1].set_xlabel(xlabel)
axes[-1, -1].xaxis.set_label_coords((left + right) / 2, tick_label_bottom - labelpad, transform=fig.transFigure)
It works for the following example, while Hagne's answer won't draw ylabel (since it's outside of the canvas) and KYC's ylabel overlaps with the tick labels:
import matplotlib.pyplot as plt
import itertools
fig, axes = plt.subplots(3, 4, sharey='row', sharex=True, squeeze=False)
fig.subplots_adjust(hspace=.5)
for i, a in enumerate(itertools.chain(*axes)):
a.plot([0,4**i], [0,4**i])
a.set_title(i)
set_shared_ylabel(axes, 'common X', 'common Y')
plt.show()
Alternatively, if you are fine with colorless axis, I've modified Julian Chen's solution so ylabel won't overlap with tick labels.
Basically, we just have to set ylims of the colorless so it matches the largest ylims of the subplots so the colorless tick labels sets the correct location for the ylabel.
Again, we have to shrink the plot to prevent clipping. Here I've hard coded the amount to shrink, but you can play around to find a number that works for you or calculate it like in the method above.
import matplotlib.pyplot as plt
import itertools
fig, axes = plt.subplots(3, 4, sharey='row', sharex=True, squeeze=False)
fig.subplots_adjust(hspace=.5)
miny = maxy = 0
for i, a in enumerate(itertools.chain(*axes)):
a.plot([0,4**i], [0,4**i])
a.set_title(i)
miny = min(miny, a.get_ylim()[0])
maxy = max(maxy, a.get_ylim()[1])
# add a big axes, hide frame
# set ylim to match the largest range of any subplot
ax_invis = fig.add_subplot(111, frameon=False)
ax_invis.set_ylim([miny, maxy])
# hide tick and tick label of the big axis
plt.tick_params(labelcolor='none', top=False, bottom=False, left=False, right=False)
plt.xlabel("common X")
plt.ylabel("common Y")
# shrink plot to prevent clipping
plt.subplots_adjust(left=0.15)
plt.show()

You could use "set" in axes as follows:
axes[0].set(xlabel="KartalOl", ylabel="Labeled")

Related

How to get the plot of 3D geometry with equal axes in python using matplotlib?

I am facing a problem to plot the geometry in the python using matplotlib. I would like to have a plot which can have the equal lenth in all three axes (X, Y, Z). I have written below code but it does not show any equal axes in the obtained geometry.
How can I get the plot with equal axes?
def plotting(x, y, z, figname):
fig = plt.figure(figsize = (50,50))
ax = plt.axes(projection='3d')
ax.grid()
ax.scatter(x, y, z, c = 'r', s = 50)
ax.set_title(figname)
ax.set_xlabel('x', labelpad=20)
ax.set_ylabel('y', labelpad=20)
ax.set_zlabel('z', labelpad=20)
Matplotlib makes this very difficult. One way you could "achieve" that is by setting the same limits to xlim, ylim, zlim:
import numpy as np
import matplotlib.pyplot as plt
n = 1000
t = np.random.uniform(0, 2*np.pi, n)
p = np.random.uniform(0, 2*np.pi, n)
x = (4 + np.cos(t)) * np.cos(p)
y = (1.5 + np.cos(t)) * np.sin(p)
z = np.sin(t)
fig = plt.figure()
ax = fig.add_subplot(projection="3d")
ax.scatter(x, y, z)
ax.set_xlim(-4, 4)
ax.set_ylim(-4, 4)
ax.set_zlim(-4, 4)
plt.show()
Otherwise, your best bet is to use a different plotting library for 3D plots. Plotly allows to easily set equal aspect ratio. K3D-Jupyter and Mayavi uses equal aspect ratio by default.

Top and right axes labels in matplotlib pyplot

I have a matplotlib/pyplot plot that appears as I want, in that the axes show the required range of values from -1 to +1 on both the x and y axes. I have labelled the x and y axes. However I also wish to label the right-hand vertical axis with the text "Thinking" and the top axis with the text "Extraversion".
I have looked at the matplotlib documentation but can't get my code to execute using set_xlabel and set_ylabel. I have commented these lines out in my code so my code runs for now - but hopefully the comments will make it clear enough what I am trying to do.
import matplotlib.pyplot as plt
w = 6
h = 6
d = 70
plt.figure(figsize=(w, h), dpi=d)
x = [-0.34,-0.155,0.845,0.66,-0.34]
y = [0.76,0.24,-0.265,0.735,0.76,]
plt.plot(x, y)
plt.xlim(-1,1)
plt.ylim(-1,1)
plt.xlabel("Intraverted")
plt.ylabel("Feeling")
#secax = plt.secondary_xaxis('top')
#secax.set_xlabel('Extraverted')
#secay = plt.secondary_xaxis('right')
#secay.set_ylabel('Thinking')
#plt.show()
plt.savefig("out.png")
As #Mr. T pointed out, there is no plt.secondary_xaxis method so you need the axes object
import matplotlib.pyplot as plt
plt.figure(figsize=(6, 6), constrained_layout=True, dpi=70)
x = [-0.34,-0.155,0.845,0.66,-0.34]
y = [0.76,0.24,-0.265,0.735,0.76,]
plt.plot(x, y)
plt.xlim(-1,1)
plt.ylim(-1,1)
plt.xlabel("Intraverted")
plt.ylabel("Feeling")
secax = plt.gca().secondary_xaxis('top')
secax.set_xlabel('Extraverted')
secay = plt.gca().secondary_yaxis('right')
secay.set_ylabel('Thinking')
#plt.show()
plt.savefig("out.png")
Better, would be just to create the axes object from the start:
fig, ax = plt.subplots(figsize=(w, h), constrained_layout=True, dpi=d)
...
ax.plot(x, y)
ax.set_xlim(-1, 1)
...
secax = ax.secondary_xaxis('top')
...
fig.savefig("out.png")
Further note the use of constrained_layout=True to make the secondary yaxis label fit on the figure.
i solved it with plt.subplots()
import matplotlib.pyplot as plt
w = 6
h = 6
d = 70
plt.figure(figsize=(w, h), dpi=d)
x = [-0.34,-0.155,0.845,0.66,-0.34]
y = [0.76,0.24,-0.265,0.735,0.76,]
fig , ax1 = plt.subplots()
ax1.plot(x, y)
plt.xlim(-1,1)
plt.ylim(-1,1)
plt.xlabel("Intraverted")
plt.ylabel("Feeling")
ax2 = ax1.twinx()
plt.ylabel('right corner')

How to draw vertical average lines for overlapping histograms in a loop

I'm trying to draw with matplotlib two average vertical line for every overlapping histograms using a loop. I have managed to draw the first one, but I don't know how to draw the second one. I'm using two variables from a dataset to draw the histograms. One variable (feat) is categorical (0 - 1), and the other one (objective) is numerical. The code is the following:
for chas in df[feat].unique():
plt.hist(df.loc[df[feat] == chas, objective], bins = 15, alpha = 0.5, density = True, label = chas)
plt.axvline(df[objective].mean(), linestyle = 'dashed', linewidth = 2)
plt.title(objective)
plt.legend(loc = 'upper right')
I also have to add to the legend the mean and standard deviation values for each histogram.
How can I do it? Thank you in advance.
I recommend you using axes to plot your figure. Pls see code below and the artist tutorial here.
import numpy as np
import matplotlib.pyplot as plt
# Fixing random state for reproducibility
np.random.seed(19680801)
mu1, sigma1 = 100, 8
mu2, sigma2 = 150, 15
x1 = mu1 + sigma1 * np.random.randn(10000)
x2 = mu2 + sigma2 * np.random.randn(10000)
fig, ax = plt.subplots(1, 1, figsize=(7.2, 7.2))
# the histogram of the data
lbs = ['a', 'b']
colors = ['r', 'g']
for i, x in enumerate([x1, x2]):
n, bins, patches = ax.hist(x, 50, density=True, facecolor=colors[i], alpha=0.75, label=lbs[i])
ax.axvline(bins.mean())
ax.legend()

How to iterate a list of list for a scatter plot and create a legend of unique elements

Background:
I have a list_of_x_and_y_list that contains x and y values which looks like:
[[(44800, 14888), (132000, 12500), (40554, 12900)], [(None, 193788), (101653, 78880), (3866, 160000)]]
I have another data_name_list ["data_a","data_b"] so that
"data_a" = [(44800, 14888), (132000, 12500), (40554, 12900)]
"data_b" = [(None, 193788), (101653, 78880), (3866, 160000)]
The len of list_of_x_and_y_list / or len of data_name_list is > 20.
Question:
How can I create a scatter plot for each item (being the same colour) in the data_name_list?
What I have tried:
fig = plt.figure()
ax = fig.add_subplot(1, 1, 1)
ax = plt.axes(facecolor='#FFFFFF')
prop_cycle = plt.rcParams['axes.prop_cycle']
colors = prop_cycle.by_key()['color']
print(list_of_x_and_y_list)
for x_and_y_list, data_name, color in zip(list_of_x_and_y_list, data_name_list, colors):
for x_and_y in x_and_y_list,:
print(x_and_y)
x, y = x_and_y
ax.scatter(x, y, label=data_name, color=color) # "label=data_name" creates
# a huge list as a legend!
# :(
plt.title('Matplot scatter plot')
plt.legend(loc=2)
file_name = "3kstc.png"
fig.savefig(file_name, dpi=fig.dpi)
print("Generated: {}".format(file_name))
The Problem:
The legend appears to be a very long list, which I don't know how to rectify:
Relevant Research:
Matplotlib scatterplot
Scatter Plot
Scatter plot in Python using matplotlib
The reason you get a long repeated list as a legend is because you are providing each point as a separate series, as matplotlib does not automatically group your data based on the labels.
A quick fix is to iterate over the list and zip together the x-values and the y-values of each series as two tuples, so that the x tuple contains all the x-values and the y tuple the y-values.
Then you can feed these tuples to the plt.plot method together with the labels.
I felt that the names list_of_x_and_y_list were uneccessary long and complicated, so in my code I've used shorter names.
import matplotlib.pyplot as plt
data_series = [[(44800, 14888), (132000, 12500), (40554, 12900)],
[(None, 193788), (101653, 78880), (3866, 160000)]]
data_names = ["data_a","data_b"]
fig = plt.figure()
ax = fig.add_subplot(1, 1, 1)
ax = plt.axes(facecolor='#FFFFFF')
prop_cycle = plt.rcParams['axes.prop_cycle']
colors = prop_cycle.by_key()['color']
for data, data_name, color in zip(data_series, data_names, colors):
x,y = zip(*data)
ax.scatter(x, y, label=data_name, color=color)
plt.title('Matplot scatter plot')
plt.legend(loc=1)
To only get one entry per data_name, you should add data_name only once as a label. The rest of the calls should go with label=None.
The simplest you can achieve this using the current code, is to set data_name to None at the end of the loop:
from matplotlib import pyplot as plt
from random import randint
fig = plt.figure()
ax = fig.add_subplot(1, 1, 1)
ax.set_facecolor('#FFFFFF')
# create some random data, suppose the sublists have different lengths
list_of_x_and_y_list = [[(randint(1000, 4000), randint(2000, 5000)) for col in range(randint(2, 10))]
for row in range(10)]
data_name_list = list('abcdefghij')
colors = plt.rcParams['axes.prop_cycle'].by_key()['color']
for x_and_y_list, data_name, color in zip(list_of_x_and_y_list, data_name_list, colors):
for x_and_y in x_and_y_list :
x, y = x_and_y
ax.scatter(x, y, label=data_name, color=color)
data_name = None
plt.legend(loc=2)
plt.show()
Some things can be simplified, making the code 'more pythonic', for example:
for x_and_y in x_and_y_list :
x, y = x_and_y
can be written as:
for x, y in x_and_y_list:
Another issue, is that with a lot of data calling scatter for every point could be rather slow. All the x and y belonging to the same list can be plotted together. For example using list comprehension:
for x_and_y_list, data_name, color in zip(list_of_x_and_y_list, data_name_list, colors):
xs = [x for x, y in x_and_y_list]
ys = [y for x, y in x_and_y_list]
ax.scatter(xs, ys, label=data_name, color=color)
scatter could even get a list of colors per point, but plotting all the points in one go, wouldn't allow for labels per data_name.
Very often, numpy is used to store numerical data. This has some advantages, such as vectorization for quick calculations. With numpy the code would look like:
import numpy as np
for x_and_y_list, data_name, color in zip(list_of_x_and_y_list, data_name_list, colors):
xys = np.array(x_and_y_list)
ax.scatter(xys[:,0], xys[:,1], label=data_name, color=color)

Matplotlib square major/minor grid for axes with different limits

I have a plot with a background grid. I need grid cells to be square (both major grid and minor grid cells) even though the limits of X and Y axes are different.
My current code is as follows:
import matplotlib.pyplot as plt
import matplotlib.ticker as plticker
import numpy as np
data = [0.014, 0.84, 0.95, -0.42, -0.79, 0.84, 0.98, 1.10, 0.56, -0.49]
fig, ax = plt.subplots(figsize=(20, 5))
ax.minorticks_on()
# Set major and minor grid lines on X
ax.set_xticks(np.arange(0, 10, 0.2))
ax.xaxis.set_minor_locator(plticker.MultipleLocator(base=0.2 / 5.))
for xmaj in ax.xaxis.get_majorticklocs():
ax.axvline(x=xmaj, ls='-', color='red', linewidth=0.8)
for xmin in ax.xaxis.get_minorticklocs():
ax.axvline(x=xmin, ls=':', color='red', linewidth=0.6)
# Set major and minor grid lines on Y
ylim = int(np.ceil(max(abs(min(data)), max(data))))
yticks = np.arange(-ylim, ylim + 0.5, 0.5)
ax.set_yticks(yticks)
ax.yaxis.set_minor_locator(plticker.MultipleLocator(base=0.5 / 5.))
for ymaj in ax.yaxis.get_majorticklocs():
ax.axhline(y=ymaj, ls='-', color='red', linewidth=0.8)
for ymin in ax.yaxis.get_minorticklocs():
ax.axhline(y=ymin, ls=':', color='red', linewidth=0.6)
ax.axis([0, 10, -ylim, ylim])
fig.tight_layout()
# Plot
ax.plot(data)
# Set equal aspect ratio NOT WORKING
plt.gca().set_aspect('equal', adjustable='box')
plt.show()
Which generates the following plot:
Large grid cells contain 5 smaller cells each. However, the aspect ratio of large grid is not 1.
Question: How can I make sure that large grid is square?
EDIT
Current approach is to set same tick locations as suggested by #ImportanceOfBeingErnest, but change Y labels:
ylim = int(np.ceil(max(abs(min(data)), max(data))))
yticks = np.arange(-ylim, ylim + 0.2, 0.2)
ax.set_yticks(yticks)
labels = ['{:.1f}'.format(v if abs(v) < 1e-3 else (1 if v > 0 else -1)*((0.5 - abs(v)%0.5) + abs(v)))
if i%2==0 else "" for i, v in enumerate(np.arange(-ylim, ylim, 0.2))]
ax.set_yticklabels(labels)
Result: seems too hacky.
When using equal aspect ratio and aiming for a square grid you would need to use the same tickspacing for both axes. This can be achieved with a MultipleLocator where the interval needs to be the same for x and y axis.
In general, grids can be created with the grid command.
import matplotlib.pyplot as plt
import matplotlib.ticker as mticker
import numpy as np
data = [0.014, 0.84, 0.95, -0.42, -0.79, 0.84, 0.98, 1.10, 0.56, -0.49]
fig, ax = plt.subplots(figsize=(20, 5))
ax.minorticks_on()
# Set major and minor grid lines on X
ax.xaxis.set_major_locator(mticker.MultipleLocator(base=.5))
ax.xaxis.set_minor_locator(mticker.MultipleLocator(base=0.5 / 5.))
ax.yaxis.set_major_locator(mticker.MultipleLocator(base=.5))
ax.yaxis.set_minor_locator(mticker.MultipleLocator(base=0.5 / 5.))
ax.grid(ls='-', color='red', linewidth=0.8)
ax.grid(which="minor", ls=':', color='red', linewidth=0.6)
## Set limits
ylim = int(np.ceil(max(abs(min(data)), max(data))))
ax.axis([0, 10, -ylim, ylim])
plt.gca().set_aspect('equal', adjustable='box')
fig.tight_layout()
# Plot
ax.plot(data)
plt.show()
If you instead want to have different tick spacings with square major cells in the grid, you would need to give up the equal aspect ratio and instead set it to the quotient of the tick spacings.
import matplotlib.pyplot as plt
import matplotlib.ticker as mticker
import numpy as np
data = [0.014, 0.84, 0.95, -0.42, -0.79, 0.84, 0.98, 1.10, 0.56, -0.49]
fig, ax = plt.subplots(figsize=(20, 5))
ax.minorticks_on()
xm = 0.2
ym = 0.25
# Set major and minor grid lines on X
ax.xaxis.set_major_locator(mticker.MultipleLocator(base=xm))
ax.xaxis.set_minor_locator(mticker.MultipleLocator(base=xm / 5.))
ax.yaxis.set_major_locator(mticker.MultipleLocator(base=ym))
ax.yaxis.set_minor_locator(mticker.MultipleLocator(base=ym / 5.))
ax.grid(ls='-', color='red', linewidth=0.8)
ax.grid(which="minor", ls=':', color='red', linewidth=0.6)
## Set limits
ylim = int(np.ceil(max(abs(min(data)), max(data))))
ax.axis([0, 10, -ylim, ylim])
plt.gca().set_aspect(xm/ym, adjustable='box')
fig.tight_layout()
# Plot
ax.plot(data)
plt.show()
To then get rid of every second ticklabel, an option is
fmt = lambda x,p: "%.2f" % x if not x%(2*ym) else ""
ax.yaxis.set_major_formatter(mticker.FuncFormatter(fmt))
You should be able to achieve this by using the same locator for the both axis. However matplotlib has a limitation currently, so here's a workaround:
# matplotlib doesnt (currently) allow two axis to share the same locator
# so make two wrapper locators and combine their view intervals
def share_locator(locator):
class _SharedLocator(matplotlib.ticker.Locator):
def tick_values(self, vmin, vmax):
return locator.tick_values(vmin, vmax)
def __call__(self):
min0, max0 = shared_locators[0].axis.get_view_interval()
min1, max1 = shared_locators[1].axis.get_view_interval()
return self.tick_values(min(min0, min1), max(max0, max1))
shared_locators = (_SharedLocator(), _SharedLocator())
return shared_locators
Use like:
lx, ly = share_locator(matplotlib.ticker.AutoLocator()) # or any other locator
ax.xaxis.set_major_locator(lx)
ax.yaxis.set_major_locator(ly)

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