Is it possible to read (say) 4 .jpeg graphs produced by matplotlib into matplotlib again so that they can be replotted as subplots? If so, how would I do it?
If you really want to do it by reading jpeg files of existing plots (noting the comments), one way might be to read in the graphs in with scipy.misc.imread. I've set the axis labels off assuming you saved the original graphs with labels and everything.
import matplotlib.pyplot as plt
from scipy.misc import imread
# Create a figure with 2x2 arranged subplots
fig, ax = plt.subplots(2,2)
# Plot images one by one here
# (Just using the same jpeg file in this example...)
im1 = imread("graph1.jpg")
ax[0,0].imshow(im1)
ax[0,0].axis('off')
ax[0,1].imshow(im1)
ax[0,1].axis('off')
ax[1,0].imshow(im1)
ax[1,0].axis('off')
ax[1,1].imshow(im1)
ax[1,1].axis('off')
fig.show()
Related
So here is the simple code that is producing a subplot with dark background:-
import matplotlib.pyplot as plt
fig, ax = plt.subplots(figsize=(6,6), facecolor='black')
ax.set_facecolor('black')
And I want this image which is in .svg format to be added to the subplot. While using PIL's Image.open() and plt.imread I am getting UnidentifiedImageError. What should I do to read in the .svg file and add it to the subplot.
I am plotting data from a .txt file using Matplotlib and although the plot looks as expected there is an odd horizontal line through the plot. This occurs across three different .txt data files I've tried. I plotted the data in Mathematica to ensure that it is not an artifact of the data. I am trying to remove the line from my data.
I've tried the accessing some of the Matplotlib methods like lines.remove() with no luck. Below is the code I'm executing and the resulting plot.
import numpy as np
import matplotlib.pyplot as plt
neon = np.loadtxt("data/neon.txt")
neon_plot = plt.plot(neon)
plt.grid()
This is an example of the horizontal line going through my plots
I am trying to generate the log-log plot of a vector, and save the generated plot to file.
This is what I have tried so far:
import matplotlib.pyplot as plt
...
plt.loglog(deg_distribution,'b-',marker='o')
plt.savefig('LogLog.png')
I am using Jupyter Notebook, in which I get the generated graph as output after statement 2 in the above code, but the saved file is blank.
Notice that pyplot has the concept of the current figure and the current axes. All plotting commands apply to the current axes. So, make sure you plot in the right axes. Here is a WME.
import matplotlib.pyplot as plt
fig, ax = plt.subplots()
ax.loglog(range(100), 'b-',marker='o')
plt.savefig('test.png') # apply to the axes `ax`
Update: The fonts issue was actaully solved by using rc("pdf", fonttype=42) but unfortunately it is combined with another - whenever is used any type of marker I tried CorelDraw comes with error "File is corrupted".
When I output my charts from Matplotlib into PDF I am not able to open it in Corel Draw. I highly suspect that the major issue might be with texts / fonts.
Simple code example which I need update to make PDF with text and markers import correctly in Corel Draw:
from matplotlib.backends.backend_pdf import PdfPages
import matplotlib.pyplot as plt
from matplotlib import rc
rc("pdf", fonttype=42)
with PdfPages("simple.pdf") as pdf:
points_y = points_x = [1,2,3]
plt.plot(points_x, points_y, marker="o")
pdf.savefig()
plt.close()
Example of Corel vs Matplotlib / PDF Reader when not used rc("pdf", fonttype=42) and marker. If marker used PDF doesn't open and CorelDraw says "File is corrupted".
It turned out there are two important issues which ruins import of Matplotlib generated PDF into CorelDraw.
Setting up the font type from the default rc("pdf", fonttype=3) to rc("pdf", fonttype=42)
Not using multiple markers. Only one marker per plot allowed! Possible to replace by text. (no pyplot.scatter, not in pyplot.plot etc.). When using any markers in number of 2 or more per plot CorelDraw finds the PDF corrupted and wont open it at all.
Code rewritten to plot only one marker per plot plus only one marker in the legend:
from matplotlib.backends.backend_pdf import PdfPages
import matplotlib.pyplot as plt
from matplotlib import rc
rc("pdf", fonttype=42)
with PdfPages("simple.pdf") as pdf:
points_y = points_x = [1,2,3]
plt.plot(points_x, points_y,color="r")
# plot points one be one otherwise "File is corrupted" in CorelDraw
# also plot first point out of loop to make appropriate legend
plt.plot(points_x[0], points_y[0],marker="o",color="r",markerfacecolor="b",label="Legend label")
for i in range(1,len(points_x)):
plt.plot(points_x[i], points_y[i],marker="o",markerfacecolor="b")
plt.legend(numpoints=1) #Only 1 point in legend because in CorelDraw "File is corrupted" if default two or more
pdf.savefig()
plt.close()
As a possible replacement for points (markers) pyplot.text can be used, for my example in question updated code looks like this:
from matplotlib.backends.backend_pdf import PdfPages
import matplotlib.pyplot as plt
from matplotlib import rc
rc("pdf", fonttype=42)
with PdfPages("simple.pdf") as pdf:
points_y = points_x = [1,2,3]
plt.plot(points_x, points_y)
# print points as + symbol
for i in range(len(points_x)):
plt.text(points_x[i], points_y[i],"+",ha="center", va="center")
pdf.savefig()
plt.close()
I would like to create a pdf file [by using plt.savefig("~~~.pdf")]
containing lots of (about 20) subplots
each of which is drawing timeseries data.
I am using a matplotlib library with python language.
Each subplot may be long, and I want to put the subplots
horizontally.
Therefore, the figure should be very long (horizontally), so the horizontal scroll bar should be needed!
Is there any way to do this?
some example code will be appreciated!
The following is my sample code.
I just wanted to draw 10 sine graphs arranged horizontally
and save it as pdf file.
(but I'm not pretty good at this. so the code may looks to be weird to you.. :( )
from matplotlib import pyplot as plt
import numpy as np
x=np.linspace(0,100,1000)
y=np.sin(x)
numplots=10
nr=1
nc=numplots
size_x=nc*50
size_y=size_x*3/4
fig=plt.figure(1,figsize=(size_x,size_y))
for i in range(nc):
ctr=i+1
ax=fig.add_subplot(nr,nc,ctr)
ax.plot(x,y)
plt.savefig("longplot.pdf")
plt.clf()
Thank you!
You should do that using the backend "matplotlib.backends.backend_pdf". This enables you to save matplotlib graphs in pdf format.
I have simplified your code a bit, here is a working example:
from matplotlib import pyplot as plt
import numpy as np
from matplotlib.backends.backend_pdf import PdfPages
x = np.linspace(0,100,1000)
y = np.sin(x)
nr = 10
nc = 1
for i in range(nr):
plt.subplot(nr, nc, i + 1)
plt.plot(x, y)
pdf = PdfPages('longplot.pdf')
pdf.savefig()
pdf.close()
I hope this helps.
In the link below there is a solution, which can help you, since it was helpful to me either.
Scrollbar on Matplotlib showing page
But if you have many subplots, I am afraid your problem won't be solved. Since it will shrink each graph anyway. In that case it will be better to break your graphs into smaller and separate parts.