Two different plots from same loop in matplotlib? - python

I would specifically like to create two different plots using one single loop. One plot should have four straight lines from x-y, and another plot should have four angled lines from x-y2. My code only shows everything in a single plot. I don't quite understand how plt works, how can I create two distinct plt objects?
import matplotlib.pyplot as plt
import matplotlib.pyplot as plt2
x=[[1,2,3,4],[1,2,3,4],[1,2,3,4],[1,2,3,4]]
y=[[1,2,3,4],[2,3,4,5],[3,4,5,6],[7,8,9,10]]
y2=[[11,12,13,24],[42,33,34,65],[23,54,65,86],[77,90,39,54]]
colours=['r','g','b','k']
for i in range(len(x)):
plt.plot(x[i],y2[i],colours[i])
plt2.plot(x[i],y[i],colours[i])
plt.show()
plt2.show()

Is that what you want to do?
import matplotlib.pyplot as plt
x=[[1,2,3,4],[1,2,3,4],[1,2,3,4],[1,2,3,4]]
y=[[1,2,3,4],[2,3,4,5],[3,4,5,6],[7,8,9,10]]
y2=[[11,12,13,24],[42,33,34,65],[23,54,65,86],[77,90,39,54]]
colours=['r','g','b','k']
fig1, ax1 = plt.subplots()
fig2, ax2 = plt.subplots()
for i in range(len(x)):
ax1.plot(x[i],y2[i],colours[i])
ax2.plot(x[i],y[i],colours[i])
fig1.show()
fig2.show()

Related

Generate more plots separate in figure in one script in python

First of all, I apologies if this question was already asked and answered, I haven't found anything really specific about this so if you did, please share and I will delete this post.
What I would like to do is simply generate more separate plots after one another in separate figure in python, because I have an exercise sheet and the a) is to plot a poisson distribution and the b) is to plot a binomial distribution and so ever with c) and d), and I would like that the plots are gathered together in the same script but in separate figure.
I tried as simple as create a sin(x) and a cos(x) plot after one another but it didn't work, the sin and cos were displaying in the same plot.. My code was:
import numpy as np
import matplotlib
import matplotlib.pyplot as plt
fig = plt.figure()
ax1 = plt.plot(np.sin(x))
ax2 = plt.plot(np.cos(x))
ax1.set_xlabel('Time (s)')
ax1.set_title('sin')
ax1.legend()
ax2.set_xlabel('Time (s)')
ax2.set_title('cos')
ax2.legend()
plt.show()
Could anyone help me ?
How about this?
import numpy as np
import matplotlib.pyplot as plt
x = np.linspace(0, 10, 100)
fig = plt.figure()
ax1 = fig.add_subplot(211)
ax2 = fig.add_subplot(212, sharex=ax1)
ax1.plot(np.sin(x))
ax2.plot(np.cos(x))
plt.show()
I suggest you should read a simple tutorial about subplots.
EDIT:
To create separate figures:
import numpy as np
import matplotlib.pyplot as plt
x = np.linspace(0, 10, 100)
plt.figure()
plt.plot(np.sin(x))
plt.figure()
plt.plot(np.cos(x))
plt.show()

Matplotlib graph with typical linestyle not showing

I want a very simple plot:
import matplotlib.pyplot as plt
import numpy as np
for t in np.linspace(0,2*np.pi,100):
plt.plot(np.cos(t), np.sin(t), color='blue', linestyle='-', linewidth=7)
plt.show()
But nothing is appearing. I just get an empty plot. Where is my error?
Just plot the whole arrays:
import matplotlib.pyplot as plt
import numpy as np
t = np.linspace(0,2*np.pi,100):
plt.plot(np.cos(t), np.sin(t), color='blue', linestyle='-',linewidth=7)
plt.show()
Each call to plt.plot within the for loop is plotting a separate 'line' that consists on only a single point.
if you want the code to work you should plot points instead of lines.
for t in np.linspace(0,2*np.pi,100): plt.plot(np.cos(t), np.sin(t), 'k.')

Histogram at specific coordinates inside axes

What I want to achieve with Python 3.6 is something like this :
Obviously made in paint and missing some ticks on the xAxis. Is something like this possible? Essentially, can I control exactly where to plot a histogram (and with what orientation)?
I specifically want them to be on the same axes just like the figure above and not on separate axes or subplots.
fig = plt.figure()
ax2Handler = fig.gca()
ax2Handler.scatter(np.array(np.arange(0,len(xData),1)), xData)
ax2Handler.hist(xData,bins=60,orientation='horizontal',normed=True)
This and other approaches (of inverting the axes) gave me no results. xData is loaded from a panda dataframe.
# This also doesn't work as intended
fig = plt.figure()
axHistHandler = fig.gca()
axScatterHandler = fig.gca()
axHistHandler.invert_xaxis()
axHistHandler.hist(xData,orientation='horizontal')
axScatterHandler.scatter(np.array(np.arange(0,len(xData),1)), xData)
A. using two axes
There is simply no reason not to use two different axes. The plot from the question can easily be reproduced with two different axes:
import numpy as np
import matplotlib.pyplot as plt
plt.style.use("ggplot")
xData = np.random.rand(1000)
fig,(ax,ax2)= plt.subplots(ncols=2, sharey=True)
fig.subplots_adjust(wspace=0)
ax2.scatter(np.linspace(0,1,len(xData)), xData, s=9)
ax.hist(xData,bins=60,orientation='horizontal',normed=True)
ax.invert_xaxis()
ax.spines['right'].set_visible(False)
ax2.spines['left'].set_visible(False)
ax2.tick_params(axis="y", left=0)
plt.show()
B. using a single axes
Just for the sake of answering the question: In order to plot both in the same axes, one can shift the bars by their length towards the left, effectively giving a mirrored histogram.
import numpy as np
import matplotlib.pyplot as plt
plt.style.use("ggplot")
xData = np.random.rand(1000)
fig,ax= plt.subplots(ncols=1)
fig.subplots_adjust(wspace=0)
ax.scatter(np.linspace(0,1,len(xData)), xData, s=9)
xlim1 = ax.get_xlim()
_,__,bars = ax.hist(xData,bins=60,orientation='horizontal',normed=True)
for bar in bars:
bar.set_x(-bar.get_width())
xlim2 = ax.get_xlim()
ax.set_xlim(-xlim2[1],xlim1[1])
plt.show()
You might be interested in seaborn jointplots:
# Import and fake data
import seaborn as sns
import numpy as np
import matplotlib.pyplot as plt
data = np.random.randn(2,1000)
# actual plot
jg = sns.jointplot(data[0], data[1], marginal_kws={"bins":100})
jg.ax_marg_x.set_visible(False) # remove the top axis
plt.subplots_adjust(top=1.15) # fill the empty space
produces this:
See more examples of bivariate distribution representations, available in Seaborn.

Matplotlib copy/duplicate a 3D figure?

I've tried to find a way to copy a 3D figure in matplotlib but I didn't find a solution which is appropriate in my case.
From these posts
How do I reuse plots in matplotlib?
and
How to combine several matplotlib figures into one figure?
Using fig2._axstack.add(fig2._make_key(ax),ax) as in the code below gives quite the good result but figure 2 is not interactive I can't rotate the figure etc :
import matplotlib.pyplot as plt
from mpl_toolkits.mplot3d import Axes3D
fig = plt.figure(1)
ax = fig.gca(projection = '3d')
ax.plot([0,1],[0,1],[0,1])
fig2 = plt.figure(2)
fig2._axstack.add(fig2._make_key(ax),ax)
plt.show()
An alternative would be to copy objects from ax to ax2 using a copy method proposed in this post How do I reuse plots in matplotlib? but executing the code below returns RuntimeError: Can not put single artist in more than one figure :
import matplotlib.pyplot as plt
from mpl_toolkits.mplot3d import Axes3D
import numpy as np, copy
fig = plt.figure(1)
ax = fig.gca(projection = '3d')
ax.plot([0,1],[0,1],[0,1])
fig2 = plt.figure(2)
ax2 = fig2.gca(projection = '3d')
for n in range(len(ax.lines)) :
ax2.add_line(copy.copy(ax.lines[n]))
plt.show()
Those codes are pretty simple but I don't want to copy/paste part of my code for drawing similar figures
Thanks in advance for your reply !

Drawing lines between two plots in Matplotlib

I am drawing two subplots with Matplotlib, essentially following :
subplot(211); imshow(a); scatter(..., ...)
subplot(212); imshow(b); scatter(..., ...)
Can I draw lines between those two subplots? How would I do that?
The solution from the other answers are suboptimal in many cases (as they would only work if no changes are made to the plot after calculating the points).
A better solution would use the specially designed ConnectionPatch:
import matplotlib.pyplot as plt
from matplotlib.patches import ConnectionPatch
import numpy as np
fig = plt.figure(figsize=(10,5))
ax1 = fig.add_subplot(121)
ax2 = fig.add_subplot(122)
x,y = np.random.rand(100),np.random.rand(100)
ax1.plot(x,y,'ko')
ax2.plot(x,y,'ko')
i = 10
xy = (x[i],y[i])
con = ConnectionPatch(xyA=xy, xyB=xy, coordsA="data", coordsB="data",
axesA=ax2, axesB=ax1, color="red")
ax2.add_artist(con)
ax1.plot(x[i],y[i],'ro',markersize=10)
ax2.plot(x[i],y[i],'ro',markersize=10)
plt.show()
You could use fig.line. It adds any line to your figure. Figure lines are higher level than axis lines, so you don't need any axis to draw it.
This example marks the same point on the two axes. It's necessary to be careful with the coordinate system, but the transform does all the hard work for you.
import matplotlib.pyplot as plt
import matplotlib
import numpy as np
fig = plt.figure(figsize=(10,5))
ax1 = fig.add_subplot(121)
ax2 = fig.add_subplot(122)
x,y = np.random.rand(100),np.random.rand(100)
ax1.plot(x,y,'ko')
ax2.plot(x,y,'ko')
i = 10
transFigure = fig.transFigure.inverted()
coord1 = transFigure.transform(ax1.transData.transform([x[i],y[i]]))
coord2 = transFigure.transform(ax2.transData.transform([x[i],y[i]]))
line = matplotlib.lines.Line2D((coord1[0],coord2[0]),(coord1[1],coord2[1]),
transform=fig.transFigure)
fig.lines = line,
ax1.plot(x[i],y[i],'ro',markersize=20)
ax2.plot(x[i],y[i],'ro',markersize=20)
plt.show()
I'm not sure if this is exactly what you are looking for, but a simple trick to plot across subplots.
import matplotlib.pyplot as plt
import numpy as np
ax1=plt.figure(1).add_subplot(211)
ax2=plt.figure(1).add_subplot(212)
x_data=np.linspace(0,10,20)
ax1.plot(x_data, x_data**2,'o')
ax2.plot(x_data, x_data**3, 'o')
ax3 = plt.figure(1).add_subplot(111)
ax3.plot([5,5],[0,1],'--')
ax3.set_xlim([0,10])
ax3.axis("off")
plt.show()

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