EDIT: My question was closed because someone thought another question was responding to it (but it doesn't: Matplotlib different size subplots). To clarify what I want:
I would like to replicate something like what is done on this photo: having a 3rd dataset plotted on top of 2 subplots, with its y-axis displayed on the right.
I have 3 datasets spanning the same time interval (speed, position, precipitation). I would like to plot the speed and position in 2 horizontal subplots, and the precipitation spanning the 2 subplots.
For example in the code below, instead of having the twinx() only on the first subplot, I would like to have it overlap the two subplots (ie. on the right side have a y-axis with 0 at the bottom right of the 2nd subplot, and 20 at the top right of the 1st subplot).
I could I achieve that ?
import matplotlib.pyplot as plt
import numpy as np
fig, ax = plt.subplots(2,1,figsize=(20,15), dpi = 600)
#plot 1:
x = np.array([0, 1, 2, 3])
y = np.array([3, 8, 1, 10])
ax[0].plot(x,y, label = 'speed')
plt.legend()
#plot 2:
x = np.array([0, 1, 2, 3])
y = np.array([3, 8, 1, 10])
ax[1].plot(x,y, label = 'position')
plt.legend()
#plot 3:
x = np.array([0, 1, 2, 3])
y = np.array([10, 0, 4, 20])
ax2=ax[0].twinx()
ax2.plot(x,y, label = 'precipitation')
plt.legend(loc='upper right')
plt.show()
Best way I found is not very elegant but it works:
# Prepare 2 subplots
fig, ax = plt.subplots(2,1,figsize=(20,15), dpi = 600)
#plot 1:
# Dummy values for plotting
x = np.array([0, 1, 2, 3])
y = np.array([3, 8, 1, 10])
ax[0].plot(x,y, label = 'speed')
# Prints the legend
plt.legend()
#plot 2:
x = np.array([0, 1, 2, 3])
y = np.array([3, 8, 1, 10])
ax[1].plot(x,y, label = 'position')
plt.legend()
#plot 3:
x = np.array([0, 1, 2, 3])
y = np.array([10, 0, 4, 20])
# Add manually a 3rd subplot that stands on top of the 2 others
ax2 = fig.add_subplot(111, label="new subplot", facecolor="none")
# Move the y-axis to the right otherwise it will overlap with the ones on the left
ax2.yaxis.set_label_position("right")
# "Erase" every tick and label of this 3rd plot
ax2.tick_params(left=False, right=True, labelleft=False, labelright=True,
bottom=False, labelbottom=False)
# This line merges the x axes of the 1st and 3rd plot, and indicates
# that the y-axis of the 3rd plot will be drawn on the entirety of the
# figure instead of just 1 subplot (because fig.add_subplot(111) makes it spread on the entirety of the figure)
ax[0].get_shared_x_axes().join(ax[0],ax2)
ax2.plot(x,y, label = 'precipitation')
# Prints the legend in the upper right corner
plt.legend(loc='upper right')
plt.show()
Related
I need to draw 4 X vs Y plots, where X is constant but different Y Values. I used below code to get the plots but need to show the Y scale on either side of the Secondary Y axes (Y Axis 2 in the image), the way Primary Y Axis has (both inward and outward). Right now, it comes on same side of Secondary Y Axis. How to modify the below code to get this done.
import matplotlib.pyplot as plt
fig, ax = plt.subplots()
fig.subplots_adjust(left=0.1,right=0.9)
twin2 = ax.twinx()
twin3 = ax.twinx()
twin4 = ax.twinx()
twin3.spines['right'].set_position(("axes", 0.0))
twin4.spines['right'].set_position(('axes', 1.0))
p1, = ax.plot([0, 1, 2], [0, 1, 2], "b-", label="plot1")
p2, = twin2.plot([0, 1, 2], [0, 3, 2], "r-", label="plot2")
p3, = twin3.plot([0, 1, 2], [50, 30, 15], "g-", label="plot3")
p4, = twin4.plot([0, 1, 2], [5, 3, 1], "y-", label="plot4")
ax.set_xlim(0, 2)
ax.set_ylim(0, 2)
ax.set_xlabel("X Axis")
ax.set_ylabel("Y Axis")
twin2.set_ylabel("Y Axis 2")
plt.show()
On your 4th axes, set tick_left and move the left spine to the right-hand side:
twin4.yaxis.tick_left()
twin4.spines['left'].set_position(('axes', 1.0))
In Python matplotlib, how can you get the line in a line or step plot to display a gradient based on the y-value?
Example plot (made in Tableau):
Code for step plot with a line that changes gradient according to x-value, adapted from this answer:
fig, ax = plt.subplots(figsize=(10, 4))
x = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11]
y = [2, 3, 9, 10, 2, 9, 0, 1, 9, 1, -8]
T = np.linspace(0,1,np.size(x))**2
s = 1
for i in range(0, len(x)-s, s):
ax.step(x[i:i+s+1], y[i:i+s+1], marker='.', color=(0.0,0.5,T[i]))
ax.tick_params(axis='both', colors='lightgray', labelsize=8)
The following code is inspired by the multicolored-line example from the matplotlib docs. First the horizontal line segments are drawn and colored using their y-value. The vertical segments are subdivided in small chunks to colored individually.
vmin of the norm is set a bit lower to avoid the too-light range of the colormap.
import matplotlib.pyplot as plt
from matplotlib.collections import LineCollection
import numpy as np
x = np.arange(50)
y = np.random.randint(-3, 4, x.size).cumsum()
fig, ax = plt.subplots()
norm = plt.Normalize(y.min() - y.ptp() * .2, y.max())
cmap = 'inferno_r' # 'Reds'
horizontal_lines = np.array([x[:-1], y[:-1], x[1:], y[:-1]]).T.reshape(-1, 2, 2)
hor_lc = LineCollection(horizontal_lines, cmap=cmap, norm=norm)
hor_lc.set_array(y[:-1])
ax.add_collection(hor_lc)
factor = 10
long_y0 = np.linspace(y[:-1], y[1:], factor)[:-1, :].T.ravel()
long_y1 = np.linspace(y[:-1], y[1:], factor)[1:, :].T.ravel()
long_x = np.repeat(x[1:], factor - 1)
vertical_lines = np.array([long_x, long_y0, long_x, long_y1]).T.reshape(-1, 2, 2)
ver_lc = LineCollection(vertical_lines, cmap=cmap, norm=norm)
ver_lc.set_array((long_y0 + long_y1) / 2)
ax.add_collection(ver_lc)
ax.scatter(x, y, c=y, cmap=cmap, norm=norm)
plt.autoscale() # needed in case the scatter plot would be omited
plt.show()
Here is another example, with a black background. In this case the darkest part of the colormap is avoided. The changed code parts are:
y = np.random.randint(-9, 10, x.size)
ax.patch.set_color('black')
norm = plt.Normalize(y.min(), y.max() + y.ptp() * .2)
cmap = 'plasma_r'
Here is an example with a TwoSlopeNorm and the blue-white-red colormap:
from matplotlib.colors import TwoSlopeNorm
y = np.random.uniform(-1, 1, x.size * 10).cumsum()[::10]
y = (y - y.min()) / y.ptp() * 15 - 5
norm = TwoSlopeNorm(vmin=-5, vcenter=0, vmax=10)
cmap = 'bwr'
I have 6 points in the (x,y) plane: x=[x1,x2,x3,x4,x5,x6] and y=[y1,y2,y3,y4,y5,y6]
import matplotlib.pyplot as plt
x = [0, 2, 4, 0, 2, 4, 0, 2, 4]
y = [0, 0, 0, 3, 3, 3, 7, 7, 7]
plt.scatter(x, y)
plt.show()
I want to between the points, draw entirely parallel lines on each axis x,y(like photo). and how to hide x and y axis on diagram. I want to draw a 2D view of the beams and columns of 3 story building; does matplotlib bring me to my goal or should I go to other libraries?
Absolutely matplotlib can do this. Take a look at their Rectangle Patch:
Example usage (you'll have to modify this to your needs):
import matplotlib.pyplot as plt
import matplotlib.patches as patches
fig = plt.figure()
ax = fig.add_subplot()
rect = patches.Rectangle(
(0.1, 0.1),
0.5,
0.5,
fill=False
)
ax.add_patch(rect)
fig.show()
I have 2 lists, each has 128 elements
x = [1,2,3,...,128]
y = [y1,y2,...,y128]
How should I use matplotlib to plot (x,y) with x axis appearing as shown in this screenshot?
To replicate the graph, I have (1) created 2 additional lists from the original lists, and (2) used set_xticklabels:
f, ax1 = plt.subplots(1,1,figsize=(16,7))
x1 = [1, 2, 4, 8, 16, 32, 64, 128]
y1 = [y[0],y[1],y[3],y[7],y[15],y[31],y[63],y[127]]
line1 = ax1.plot(x1,y1,label="Performance",color='b',linestyle="-")
ax1.set_xticklabels([0,1,2,4,8,16,32,64,128])
ax1.set_xlabel('Time Period',fontsize=15)
ax1.set_ylabel("Value",color='b',fontsize=15)
The problem with this approach is that only 8 pairs of value are plotted, and 120 pairs are ommitted.
If my comments aren't clear enough, please, ask. :)
from matplotlib import pyplot as plt
# Instanciating my lists...
f = lambda x:x**2
x = [nb for nb in range(1, 129)]
y = [f(nb) for nb in x]
# New values you want to plot, with linear spacing.
indexes_to_keep = [1, 2, 4, 8, 16, 32, 64, 128]
y_to_use = [y[nb - 1] for nb in indexes_to_keep]
# First plot that shows the 128 points as a whole.
fig = plt.figure(figsize=(10, 5.4))
ax1 = fig.add_subplot(121)
ax1.plot(x, y)
ax1.set_title('Former values')
# Second plot that shows only the indexes you wish to keep.
ax2 = fig.add_subplot(122)
# my_ticks = [1, 2, 3, 4, 5, 6, 7]
# meaning : my_ticks will be linear values.
my_ticks = [i for i in range(len(indexes_to_keep))]
# We set the ticks we want to show, meaning : all our list
# instead of some linear spacing matplotlib will show by default
ax2.set_xticks(my_ticks)
# Then, we manually change the name of the X ticks.
ax2.set_xticklabels(indexes_to_keep)
# We will then, plot the LINEAR x axis,
# but with respect to the y-axis values pre-processed.
ax2.plot(my_ticks, y_to_use)
ax2.set_title('New selected values with linear spacing')
plt.show()
Showing...
What you are looking for is a logarithmic scale with base 2. matplotlib provides logarithmic scales and you can define any base you want:
from matplotlib import pyplot as plt
from matplotlib.ticker import ScalarFormatter
#sample data
x = list(range(1, 130))
y = list(range(3, 260, 2))
f, ax1 = plt.subplots(1,1,figsize=(16,7))
x1 = [ 1, 2, 4, 8, 16, 32, 64, 128]
y1 = [y[0],y[1],y[3],y[7],y[15],y[31],y[63],y[127]]
#just the points, where the ticks are
ax1.plot(x1, y1,"bo-", label = "Performance")
#all other points to contrast this
ax1.plot(x, [270 - i for i in y], "rx-", label = "anti-Performance")
#transform x axis into logarithmic scale with base 2
plt.xscale("log", basex = 2)
#modify x axis ticks from exponential representation to float
ax1.get_xaxis().set_major_formatter(ScalarFormatter())
ax1.set_xlabel('Time Period',fontsize=15)
ax1.set_ylabel("Value",color='b',fontsize=15)
plt.legend()
plt.show()
Output:
I am plotting to different datasets into one graph with pylab.plot(), which works great. But one dataset has values between 0% an 25% and the other has values between 75% and 100%. I want to skip 30% to 70% on the y-axis to save some space. Do you have any suggestions how this might be work with pyplot?
EDIT:
For clearness I added the following graphic. I want to skip 30% to 60% on the y axis, so that the red line and the green line come closer together.
The solution is based on Space_C0wb0ys post.
fig = pylab.figure()
ax = fig.add_subplot(111)
ax.plot( range(1,10), camean - 25, 'ro-' )
ax.plot( range(1,10), oemean , 'go-' )
ax.plot( range(1,10), hlmean , 'bo-' )
ax.set_yticks(range(5, 60, 5))
ax.set_yticklabels(["5","10","15","20","25","30","...","65","70","75"])
ax.legend(('ClassificationAccuracy','One-Error','HammingLoss'),loc='upper right')
pylab.show()
This code creates the following graphic.
You could subtract 40 from the x-values for your second functions to make the range of x-values continuous. This would give you a range from 0% to 70%. Then you can make set the tics and labes of the x-axis as follows:
x_ticks = range(71, 0, 10)
a.set_xticks(x_ticks)
a.set_xticklabels([str(x) for x in [0, 10, 20, 30, 70, 80, 90, 100]])
Where a is the current axes. So basically, you plot your functions in the range from 0% to 70%, but label the axis with a gap.
To illustrate - the following script:
from numpy import arange
import matplotlib.pyplot as plt
x1 = arange(0, 26) # first function
y1 = x1**2
x2 = arange(75, 100) # second function
y2 = x2*4 + 10
fig = plt.figure()
ax = fig.add_subplot(111)
ax.plot(x1, y1)
ax.plot(x2 - 40, y2) # shift second function 40 to left
ax.set_xticks(range(0, 61, 5)) # set custom x-ticks
# set labels for x-ticks - labels have the gap we want
ax.set_xticklabels([str(x) for x in range(0, 26, 5) + range(70, 101, 5)])
plt.show()
Produces the following plot (note the x-labels):
The matplotlib documentation actually has an example of how to do this.
The basic idea is to break up the plotting into two subplots, putting the same graph on each plot, then change the axes for each one to only show the specific part, then make it look nicer.
So, let's apply this. Imagine this is your starting code:
import matplotlib.pyplot as plt
import random, math
# Generates data
i = range(10)
x = [math.floor(random.random() * 5) + 67 for i in range(10)]
y = [math.floor(random.random() * 5) + 22 for i in range(10)]
z = [math.floor(random.random() * 5) + 13 for i in range(10)]
# Original plot
fig, ax = plt.subplots()
ax.plot(i, x, 'ro-')
ax.plot(i, y, 'go-')
ax.plot(i, z, 'bo-')
plt.show()
And we went to make it so that x is shown split off from the rest.
First, we want to plot the same graph twice, one on top of the other. To do this, the plotting function needs to be generic. Now it should look something like this:
# Plotting function
def plot(ax):
ax.plot(i, x, 'ro-')
ax.plot(i, y, 'go-')
ax.plot(i, z, 'bo-')
# Draw the graph on two subplots
fig, (ax1, ax2) = plt.subplots(2, 1)
plot(ax1)
plot(ax2)
Now this seems worse, but we can change the range for each axis to focus on what we want. For now I'm just choosing easy ranges that I know will capture all the data, but I'll focus on making the axes equal later.
# Changes graph axes
ax1.set_ylim(65, 75) # Top graph
ax2.set_ylim(5, 30) # Bottom graph
This is getting closer to what we're looking for. Now we need to just make it look a little nicer:
# Hides the spines between the axes
ax1.spines.bottom.set_visible(False)
ax2.spines.top.set_visible(False)
ax1.xaxis.tick_top()
ax1.tick_params(labeltop=False) # Don't put tick labels at the top
ax2.xaxis.tick_bottom()
# Adds slanted lines to axes
d = .5 # proportion of vertical to horizontal extent of the slanted line
kwargs = dict(
marker=[(-1, -d), (1, d)],
markersize=12,
linestyle='none',
color='k',
mec='k',
mew=1,
clip_on=False
)
ax1.plot([0, 1], [0, 0], transform=ax1.transAxes, **kwargs)
ax2.plot([0, 1], [1, 1], transform=ax2.transAxes, **kwargs)
Finally, let's fix the axes. Here you need to do a little math and decide more on the layout. For instance, maybe we want to make the top graph smaller, since the bottom graph has two lines. To do that, we need to change the height ratios for the subplots, like so:
# Draw the graph on two subplots
# Bottom graph is twice the size of the top one
fig, (ax1, ax2) = plt.subplots(2, 1, gridspec_kw={'height_ratios': [1, 2]})
Finally, It's a good idea to make the axes match. In this case, because the bottom image is twice the size of the top one, we need to change the axes of one to reflect that. I've chosen to modify the top one in this time. The bottom graph covers a range of 25, which means the top one should cover a range of 12.5.
# Changes graph axes
ax1.set_ylim(60.5, 73) # Top graph
ax2.set_ylim(5, 30) # Bottom graph
This looks good enough to me. You can play around more with the axes or tick labels if you don't want the ticks to overlap with the broken lines.
Final code:
import matplotlib.pyplot as plt
import random, math
# Generates data
i = range(10)
x = [math.floor(random.random() * 5) + 67 for i in range(10)]
y = [math.floor(random.random() * 5) + 22 for i in range(10)]
z = [math.floor(random.random() * 5) + 13 for i in range(10)]
# Plotting function
def plot(ax):
ax.plot(i, x, 'ro-')
ax.plot(i, y, 'go-')
ax.plot(i, z, 'bo-')
# Draw the graph on two subplots
# Bottom graph is twice the size of the top one
fig, (ax1, ax2) = plt.subplots(2, 1, gridspec_kw={'height_ratios': [1, 2]})
plot(ax1)
plot(ax2)
# Changes graph axes
ax1.set_ylim(60.5, 73) # Top graph
ax2.set_ylim(5, 30) # Bottom graph
# Hides the spines between the axes
ax1.spines.bottom.set_visible(False)
ax2.spines.top.set_visible(False)
ax1.xaxis.tick_top()
ax1.tick_params(labeltop=False) # Don't put tick labels at the top
ax2.xaxis.tick_bottom()
# Adds slanted lines to axes
d = .5 # proportion of vertical to horizontal extent of the slanted line
kwargs = dict(
marker=[(-1, -d), (1, d)],
markersize=12,
linestyle='none',
color='k',
mec='k',
mew=1,
clip_on=False
)
ax1.plot([0, 1], [0, 0], transform=ax1.transAxes, **kwargs)
ax2.plot([0, 1], [1, 1], transform=ax2.transAxes, **kwargs)
plt.show()