python saving multiple subplot figures to pdf - python

I am new with python I am trying to save a huge bunch of data into a pdf with figures using PdfPages of matplotlib and subplots. Problem is that I found a blottleneck I dont know how to solve, the code goes something like:
import matplotlib.pyplot as plt
from matplotlib.backends.backend_pdf import PdfPages
with PdfPages('myfigures.pdf') as pdf:
for i in range(1000):
f,axarr = plt.subplots(2, 3)
plt.subplots(2, 3)
axarr[0, 0].plot(x1, y1)
axarr[1, 0].plot(x2, y2)
pdf.savefig(f)
plt.close('all')
Creating a figure each loop it is highly time consuming, but if I put that outside the loop it doesnt clear each plot. Other options I tried like clear() or clf() didnt work either or ended in creating multiple different figures, anyone as an idea on how to put this in a different way so that it goes faster?

Multipage PDF appending w/ matplotlib
Create 𝑚-rows × 𝑛-cols matrices of subplot axes arrays per pdf page & save (append) as each page's matrix of subplots becomes completely full → then create new page, repeat, 𝐞𝐭𝐜.
To contain large numbers of subplots as multipage output inside a single pdf, immediately start filling the first page with your plot(s), then you'll need to create a new page after detecting that the latest subplot addition in your iteration of plot generation has maxed out the available space in the current page's 𝑚-rows × 𝑛-cols subplot-array layout [i.e., an 𝑚 × 𝑛 matrix of subplots], as applicable.
Here's a way to do it where the dimensions (𝑚 × 𝑛) controlling the number of subplots per page can easily be changed:
import sys
import matplotlib
from matplotlib.backends.backend_pdf import PdfPages
import matplotlib.pyplot as plt
import numpy as np
matplotlib.rcParams.update({"font.size": 6})
# Dimensions for any m-rows × n-cols array of subplots / pg.
m, n = 4, 5
# Don't forget to indent after the with statement
with PdfPages("auto_subplotting.pdf") as pdf:
"""Before beginning the iteration through all the data,
initialize the layout for the plots and create a
representation of the subplots that can be easily
iterated over for knowing when to create the next page
(and also for custom settings like partial axes labels)"""
f, axarr = plt.subplots(m, n, sharex="col", sharey="row")
arr_ij = [(x, y) for x, y in np.ndindex(axarr.shape)]
subplots = [axarr[index] for index in arr_ij]
# To conserve needed plotting real estate,
# only label the bottom row and leftmost subplots
# as determined automatically using m and n
splot_index = 0
for s, splot in enumerate(subplots):
splot.set_ylim(0, 0.15)
splot.set_xlim(0, 50)
last_row = m * n - s < n + 1
first_in_row = s % n == 0
if last_row:
splot.set_xlabel("X-axis label")
if first_in_row:
splot.set_ylabel("Y-axis label")
# Iterate through each sample in the data
for sample in range(33):
# As a stand-in for real data, let's just make numpy take 100 random draws
# from a poisson distribution centered around say ~25 and then display
# the outcome as a histogram
scaled_y = np.random.randint(20, 30)
random_data = np.random.poisson(scaled_y, 100)
subplots[splot_index].hist(
random_data,
bins=12,
normed=True,
fc=(0, 0, 0, 0),
lw=0.75,
ec="b",
)
# Keep collecting subplots (into the mpl-created array;
# see: [1]) through the samples in the data and increment
# a counter each time. The page will be full once the count is equal
# to the product of the user-set dimensions (i.e. m * n)
splot_index += 1
"""Once an mxn number of subplots have been collected
you now have a full page's worth, and it's time to
close and save to pdf that page and re-initialize for a
new page possibly. We can basically repeat the same
exact code block used for the first layout
initialization, but with the addition of 3 new lines:
+2 for creating & saving the just-finished pdf page,
+1 more to reset the subplot index (back to zero)"""
if splot_index == m * n:
pdf.savefig()
plt.close(f)
f, axarr = plt.subplots(m, n, sharex="col", sharey="row")
arr_ij = [(x, y) for x, y in np.ndindex(axarr.shape)]
subplots = [axarr[index] for index in arr_ij]
splot_index = 0
for s, splot in enumerate(subplots):
splot.set_ylim(0, 0.15)
splot.set_xlim(0, 50)
last_row = (m * n) - s < n + 1
first_in_row = s % n == 0
if last_row:
splot.set_xlabel("X-axis label")
if first_in_row:
splot.set_ylabel("Y-axis label")
# Done!
# But don't forget to save to pdf after the last page
pdf.savefig()
plt.close(f)
For any m×n layout, just change the declarations for the values of m and n, respectively. From the code above (where "m, n = 4, 5"), a 4x5 matrix of subplots with a total 33 samples is produced as a two-page pdf output file:
References
Link to matplotlib subplots official docs.
Note:
There will be, on the final page of the multipage PDF, a number of blank subplots equal to the remainder from the the product of your chosen subplots 𝑚 × 𝑛 layout dimension numbers and your total number of samples/data to plot. E.g., say m=3, and n=4, thus you get 3 rows of 4 subplots each equals 12 per page, and if you had say 20 samples, then there would be a two-page pdf auto-created with a total of 24 subplots with the last 4 (so full bottom-most row in this hypothetical example) of subplots on the second page empty.
Using seaborn
For a more advanced (& more "pythonic"*) extension of the implementation above, see below:
The multipage handling should probably be simplified by creating a new_page function; it's better to not repeat code verbatim*, especially if you start customizing the plots in which case you won't want to have to mirror every change and type the same thing twice. A more customized aesthetic based off of seaborn and utilizing the available matplotlib parameters like shown below might be preferable too.
Add a new_page function & some customizations for the subplot style:
import matplotlib.pyplot as plt
import numpy as np
import random
import seaborn as sns
from matplotlib.backends.backend_pdf import PdfPages
# this erases labels for any blank plots on the last page
sns.set(font_scale=0.0)
m, n = 4, 6
datasize = 37
# 37 % (m*n) = 13, (m*n) - 13 = 24 - 13 = 11. Thus 11 blank subplots on final page
# custom colors scheme / palette
ctheme = [
"k", "gray", "magenta", "fuchsia", "#be03fd", "#1e488f",
(0.44313725490196076, 0.44313725490196076, 0.88627450980392153), "#75bbfd",
"teal", "lime", "g", (0.6666674, 0.6666663, 0.29078014184397138), "y",
"#f1da7a", "tan", "orange", "maroon", "r", ] # pick whatever colors you wish
colors = sns.blend_palette(ctheme, datasize)
fz = 7 # labels fontsize
def new_page(m, n):
global splot_index
splot_index = 0
fig, axarr = plt.subplots(m, n, sharey="row")
plt.subplots_adjust(hspace=0.5, wspace=0.15)
arr_ij = [(x, y) for x, y in np.ndindex(axarr.shape)]
subplots = [axarr[index] for index in arr_ij]
for s, splot in enumerate(subplots):
splot.grid(
b=True,
which="major",
color="gray",
linestyle="-",
alpha=0.25,
zorder=1,
lw=0.5,
)
splot.set_ylim(0, 0.15)
splot.set_xlim(0, 50)
last_row = m * n - s < n + 1
first_in_row = s % n == 0
if last_row:
splot.set_xlabel("X-axis label", labelpad=8, fontsize=fz)
if first_in_row:
splot.set_ylabel("Y-axis label", labelpad=8, fontsize=fz)
return (fig, subplots)
with PdfPages("auto_subplotting_colors.pdf") as pdf:
fig, subplots = new_page(m, n)
for sample in xrange(datasize):
splot = subplots[splot_index]
splot_index += 1
scaled_y = np.random.randint(20, 30)
random_data = np.random.poisson(scaled_y, 100)
splot.hist(
random_data,
bins=12,
normed=True,
zorder=2,
alpha=0.99,
fc="white",
lw=0.75,
ec=colors.pop(),
)
splot.set_title("Sample {}".format(sample + 1), fontsize=fz)
# tick fontsize & spacing
splot.xaxis.set_tick_params(pad=4, labelsize=6)
splot.yaxis.set_tick_params(pad=4, labelsize=6)
# make new page:
if splot_index == m * n:
pdf.savefig()
plt.close(fig)
fig, subplots = new_page(m, n)
if splot_index > 0:
pdf.savefig()
plt.close(f)

Related

How to add (or annotate) value labels (or frequencies) on a matplotlib "histogram" chart

I want to add frequency labels to the histogram generated using plt.hist.
Here is the data :
np.random.seed(30)
d = np.random.randint(1, 101, size = 25)
print(sorted(d))
I looked up other questions on stackoverflow like :
Adding value labels on a matplotlib bar chart
and their answers, but apparantly, the objects returnded by plt.plot(kind='bar') are different than than those returned by plt.hist, and I got errors while using the 'get_height' or 'get width' functions, as suggested in some of the answers for bar plot.
Similarly, couldn't find the solution by going through the matplotlib documentation on histograms.
got this error
Here is how I managed it. If anyone has some suggestions to improve my answer, (specifically the for loop and using n=0, n=n+1, I think there must be a better way to write the for loop without having to use n in this manner), I'd welcome it.
# import base packages
import numpy as np
import pandas as pd
import matplotlib.pyplot as plt
# generate data
np.random.seed(30)
d = np.random.randint(1, 101, size = 25)
print(sorted(d))
# generate histogram
# a histogram returns 3 objects : n (i.e. frequncies), bins, patches
freq, bins, patches = plt.hist(d, edgecolor='white', label='d', bins=range(1,101,10))
# x coordinate for labels
bin_centers = np.diff(bins)*0.5 + bins[:-1]
n = 0
for fr, x, patch in zip(freq, bin_centers, patches):
height = int(freq[n])
plt.annotate("{}".format(height),
xy = (x, height), # top left corner of the histogram bar
xytext = (0,0.2), # offsetting label position above its bar
textcoords = "offset points", # Offset (in points) from the *xy* value
ha = 'center', va = 'bottom'
)
n = n+1
plt.legend()
plt.show;

Adding a colorbar whose color corresponds to the different lines in an existing plot

My dataset is in the form of :
Data[0] = [headValue,x0,x1,..xN]
Data[1] = [headValue_ya,ya0,ya1,..yaN]
Data[2] = [headValue_yb,yb0,yb1,..ybN]
...
Data[n] = [headvalue_yz,yz0,yz1,..yzN]
I want to plot f(y*) = x, so I can visualize all Lineplots in the same figure with different colors, each color determined by the headervalue_y*.
I also want to add a colorbar whose color matching the lines and therefore the header values, so we can link visually which header value leads to which behaviour.
Here is what I am aiming for :(Plot from Lacroix B, Letort G, Pitayu L, et al. Microtubule Dynamics Scale with Cell Size to Set Spindle Length and Assembly Timing. Dev Cell. 2018;45(4):496–511.e6. doi:10.1016/j.devcel.2018.04.022)
I have trouble adding the colorbar, I have tried to extract N colors from a colormap (N is my number of different headValues, or column -1) and then adding for each line plot the color corresponding here is my code to clarify:
import matplotlib as mpl
import matplotlib.pyplot as plt
import numpy as np
Data = [['Time',0,0.33,..200],[0.269,4,4.005,...11],[0.362,4,3.999,...16.21],...[0.347,4,3.84,...15.8]]
headValues = [0.269,0.362,0.335,0.323,0.161,0.338,0.341,0.428,0.245,0.305,0.305,0.314,0.299,0.395,0.32,0.437,0.203,0.41,0.392,0.347]
# the differents headValues_y* of each column here in a list but also in Data
# with headValue[0] = Data[1][0], headValue[1] = Data[2][0] ...
cmap = mpl.cm.get_cmap('rainbow') # I choose my colormap
rgba = [] # the color container
for value in headValues:
rgba.append(cmap(value)) # so rgba will contain a different color for each headValue
fig, (ax,ax1) = plt.subplots(2,1) # creating my figure and two axes to put the Lines and the colorbar
c = 0 # index for my colors
for i in range(1, len(Data)):
ax.plot( Data[0][1:], Data[i][1:] , color = rgba[c])
# Data[0][1:] is x, Data[i][1:] is y, and the color associated with Data[i][0]
c += 1
fig.colorbar(mpl.cm.ScalarMappable(cmap= mpl.colors.ListedColormap(rgba)), cax=ax1, orientation='horizontal')
# here I create my scalarMappable for my lineplot and with the previously selected colors 'rgba'
plt.show()
The current result:
How to add the colorbar on the side or the bottom of the first axis ?
How to properly add a scale to this colorbar correspondig to different headValues ?
How to make the colorbar scale and colors match to the different lines on the plot with the link One color = One headValue ?
I have tried to work with scatterplot which are more convenient to use with scalarMappable but no solution allows me to do all these things at once.
Here is a possible approach. As the 'headValues' aren't sorted, nor equally spaced and one is even used twice, it is not fully clear what the most-desired result would be.
Some remarks:
The standard way of creating a colorbar in matplotlib doesn't need a separate subplot. Matplotlib will reduce the existing plot a bit and put the colorbar next to it (or below for a vertical bar).
Converting the 'headValues' to a numpy array allows for compact code, e.g. writing rgba = cmap(headValues) directly calculates the complete array.
Calling cmap on unchanged values will map 0 to the lowest color and 1 to the highest color, so for values only between 0.16 and 0.44 they all will be mapped to quite similar colors. One approach is to create a norm to map 0.16 to the lowest color and 0.44 to the highest. In code: norm = plt.Normalize(headValues.min(), headValues.max()) and then calculate rgba = cmap(norm(headValues)).
import matplotlib as mpl
import matplotlib.pyplot as plt
import numpy as np
headValues = np.array([0.269, 0.362, 0.335, 0.323, 0.161, 0.338, 0.341, 0.428, 0.245, 0.305, 0.305, 0.314, 0.299, 0.395, 0.32, 0.437, 0.203, 0.41, 0.392, 0.347])
x = np.linspace(0, 200, 500)
# create Data similar to the data in the question
Data = [['Time'] + list(x)] + [[val] + list(np.sqrt(4 * x) * val + 4) for val in headValues]
headValues = np.array([d[0] for d in Data[1:]])
order = np.argsort(headValues)
inverse_order = np.argsort(order)
cmap = mpl.cm.get_cmap('rainbow')
rgba = cmap(np.linspace(0, 1, len(headValues))) # evenly spaced colors
fig, ax = plt.subplots(1, 1)
for i in range(1, len(Data)):
ax.plot(Data[0][1:], Data[i][1:], color=rgba[inverse_order[i-1]])
# Data[0][1:] is x, Data[i][1:] is y, and the color associated with Data[i-1][0]
cbar = fig.colorbar(mpl.cm.ScalarMappable(cmap=mpl.colors.ListedColormap(rgba)), orientation='vertical',
ticks=np.linspace(0, 1, len(rgba) * 2 + 1)[1::2])
cbar.set_ticklabels(headValues[order])
plt.show()
Alternatively, the colors can be assigned using their position in the colormap, but without creating
cmap = mpl.cm.get_cmap('rainbow')
norm = plt.Normalize(headValues.min(), headValues.max())
fig, ax = plt.subplots(1, 1)
for i in range(1, len(Data)):
ax.plot(Data[0][1:], Data[i][1:], color=cmap(norm(Data[i][0])))
cbar = fig.colorbar(mpl.cm.ScalarMappable(cmap=cmap, norm=norm))
To get ticks for each of the 'headValues', these ticks can be set explicitly. As putting a label for each tick will result in overlapping text, labels that are too close to other labels can be replaced by an empty string:
headValues.sort()
cbar2 = fig.colorbar(mpl.cm.ScalarMappable(cmap=cmap, norm=norm), ticks=headValues)
cbar2.set_ticklabels([val if val < next - 0.007 else '' for val, next in zip(headValues[:-1], headValues[1:])]
+ [headValues[-1]])
At the left the result of the first approach (colors in segments), at the right the alternative colorbars (color depending on value):

Bar plot animation in Matplotlib (Loop Operation)_New

I would like to animate the data points which i receive from a DL model.
I have followed the answer from here.
I had created my animated plot which satisfies my requirement.
Kindly see the picture below, where it shows X axes labels Defect & No Defect start to raise from 0 and reach a maximum point.
I want two conditions to be met, after the animation completed,
How can I annotate or display a message in the plot after the animation gets completed. (for eg : in my case I want to display maximum value - either defect or No defect in the plot based on the value)
The picture shows below is for 1 iteration which ran for 100 frames. In the same way, i have another 30 iterations data where each of them should run for 100 frames using FuncAnimtaion, which produces animation graph for each iterations and display/annotate the maximum value at the end of iterations.
I can give my 30 iterations one by one and produce results, but how one can achieve in code totally.
Picture
Code
from matplotlib import animation
import matplotlib
from matplotlib import pyplot as plt
import numpy as np
def barlist(n):
# model detail
b = n + 1
c = X_test[0][:b].reshape((-1, b, X_test.shape[2])) # Input to model
mod = model.predict_on_batch(c) # DL Model which takes input c
pred = np.argmax(mod, axis=2) # Output a array
St = np.count_nonzero(pred == 0)
Rt = np.count_nonzero(pred)
return [St, Rt] # for every frame St, Rt gets updated & animate plot
fig = plt.figure()
axes = plt.axes()
axes.set_ylim([0, 110])
x = np.arange(0,2)
my_xticks = ['Defect','No Defect']
plt.xticks(x, my_xticks)
barcollection = plt.bar(x,[0, 0], width= 0.3)
n = 100 #Number of frames
def animate(i):
y = barlist(i)
for i, b in enumerate(barcollection):
b.set_height(y[i])
anim=animation.FuncAnimation(fig,animate,repeat=False,blit=False,frames=n,interval=50)
plt.show()

Multiple subplots in triangular form using matplotlib

I have 6 lists and I want to create scatterplots for all possible combinations. This means that I want to create n(n-1)/2 combinations, so 15 plots. I have done this correctly based on the following
script.
for i in d:
for j in d:
if(j>i):
plt.cla() # Clear axis
plt.clf() # Clear figure
correlation_coefficient = str(np.corrcoef(d[i], d[j])[0][1])
plt.scatter(d[i],d[j])
plt.xlabel(names[i])
plt.ylabel(names[j])
plt.title('Correlation Coefficient: '+correlation_coefficient)
plt.grid()
plt.savefig(names[i]+"_"+names[j]+".png")
I want to save all these plots in one figure using subplot, where the first row will have the combinations (0,1) (0,2) (0,3) (0,4) (0,5) the second row (1,2) (1,3) (1,4) (1,5) the third row (2,3) (2,4) (2,5) etc.
So the final outcome will be a figure containing subplots in triangular form.
Update:
If I use subplots (code below) I was able to get somehow the result, but it is not optimal as I create a 6x6 frame whereas you can do it with 5x5.
fig = plt.figure()
cnt = 0
# Create scatterplots for all pairs
for i in d:
for j in d:
if(i>=j):
cnt=cnt+1
if(j>i):
cnt += 1
fig.add_subplot(6,6,cnt) #top left
correlation_coefficient = str(np.corrcoef(d[i], d[j])[0][1])
plt.scatter(np.log(d[i]),np.log(d[j]))
fig.savefig('test.png')
With gridspec:
from matplotlib import pyplot as plt
fig = plt.figure()
data = [(1,2,3),(8,2,3),(0,5,2),(4,7,1),(9,5,2),(8,8,8)]
plotz = len(data)
for i in range(plotz-1):
for j in range(plotz):
if(j>i) :
print(i,j)
ax = plt.subplot2grid((plotz-1, plotz-1), (i,j-1))
ax.xaxis.set_ticklabels([])
ax.yaxis.set_ticklabels([])
plt.scatter(data[i],data[j]) # might be nice with shared axis limits
fig.show()
With add_subplot, you've hit an oddity inherited from MATLAB, which 1-indexes the subplot count. (Also you have some counting errors.) Here's an example that just keeps track of the various indices:
from matplotlib import pyplot as plt
fig = plt.figure()
count = 0
data = [(1,2,3),(8,2,3),(0,5,2),(4,7,1),(9,5,2),(8,8,8)]
plotz = len(data)
for i in range(plotz-1):
for j in range(plotz):
if(j>i):
print(count, i,j, count -i)
ax = fig.add_subplot(plotz-1, plotz-1, count-i)
ax.xaxis.set_ticklabels([])
ax.yaxis.set_ticklabels([])
plt.text(.15, .5,'i %d, j %d, c %d'%(i,j,count))
count += 1
fig.show()
N.b.: the error from doing the obvious (your original code with add_subplot(5,5,cnt)) was a good hint:
...User/lib/python2.7/site-packages/matplotlib/axes.pyc in
init(self, fig, *args, **kwargs)
9249 self._subplotspec = GridSpec(rows,
cols)[num[0] - 1:num1]
9250 else:
-> 9251 self._subplotspec = GridSpec(rows, cols)[int(num) - 1]
9252 # num - 1 for converting from MATLAB to
python indexing

Multiple figures in a single window

I want to create a function which plot on screen a set of figures in a single window. By now I write this code:
import pylab as pl
def plot_figures(figures):
"""Plot a dictionary of figures.
Parameters
----------
figures : <title, figure> dictionary
"""
for title in figures:
pl.figure()
pl.imshow(figures[title])
pl.gray()
pl.title(title)
pl.axis('off')
It works perfectly but I would like to have the option for plotting all the figures in single window. And this code doesn't. I read something about subplot but it looks quite tricky.
You can define a function based on the subplots command (note the s at the end, different from the subplot command pointed by urinieto) of matplotlib.pyplot.
Below is an example of such a function, based on yours, allowing to plot multiples axes in a figure. You can define the number of rows and columns you want in the figure layout.
def plot_figures(figures, nrows = 1, ncols=1):
"""Plot a dictionary of figures.
Parameters
----------
figures : <title, figure> dictionary
ncols : number of columns of subplots wanted in the display
nrows : number of rows of subplots wanted in the figure
"""
fig, axeslist = plt.subplots(ncols=ncols, nrows=nrows)
for ind,title in enumerate(figures):
axeslist.ravel()[ind].imshow(figures[title], cmap=plt.gray())
axeslist.ravel()[ind].set_title(title)
axeslist.ravel()[ind].set_axis_off()
plt.tight_layout() # optional
Basically, the function creates a number of axes in the figures, according to the number of rows (nrows) and columns (ncols) you want, and then iterates over the list of axis to plot your images and adds the title for each of them.
Note that if you only have one image in your dictionary, your previous syntax plot_figures(figures) will work since nrows and ncols are set to 1 by default.
An example of what you can obtain:
import matplotlib.pyplot as plt
import numpy as np
# generation of a dictionary of (title, images)
number_of_im = 6
figures = {'im'+str(i): np.random.randn(100, 100) for i in range(number_of_im)}
# plot of the images in a figure, with 2 rows and 3 columns
plot_figures(figures, 2, 3)
You should use subplot.
In your case, it would be something like this (if you want them one on top of the other):
fig = pl.figure(1)
k = 1
for title in figures:
ax = fig.add_subplot(len(figures),1,k)
ax.imshow(figures[title])
ax.gray()
ax.title(title)
ax.axis('off')
k += 1
Check out the documentation for other options.
If you want to group multiple figures in one window you can do smth. like this:
import matplotlib.pyplot as plt
import numpy as np
img = plt.imread('C:/.../Download.jpg') # Path to image
img = img[0:150,50:200,0] # Define image size to be square --> Or what ever shape you want
fig = plt.figure()
nrows = 10 # Define number of columns
ncols = 10 # Define number of rows
image_heigt = 150 # Height of the image
image_width = 150 # Width of the image
pixels = np.zeros((nrows*image_heigt,ncols*image_width)) # Create
for a in range(nrows):
for b in range(ncols):
pixels[a*image_heigt:a*image_heigt+image_heigt,b*image_heigt:b*image_heigt+image_heigt] = img
plt.imshow(pixels,cmap='jet')
plt.axis('off')
plt.show()
As result you receive:
Building on the answer from: How to display multiple images in one figure correctly?, here is another method:
import math
import numpy as np
import matplotlib.pyplot as plt
def plot_images(np_images, titles = [], columns = 5, figure_size = (24, 18)):
count = np_images.shape[0]
rows = math.ceil(count / columns)
fig = plt.figure(figsize=figure_size)
subplots = []
for index in range(count):
subplots.append(fig.add_subplot(rows, columns, index + 1))
if len(titles):
subplots[-1].set_title(str(titles[index]))
plt.imshow(np_images[index])
plt.show()
You can also do this:
import matplotlib.pyplot as plt
f, axarr = plt.subplots(1, len(imgs))
for i, img in enumerate(imgs):
axarr[i].imshow(img)
plt.suptitle("Your title!")
plt.show()
def plot_figures(figures, nrows=None, ncols=None):
if not nrows or not ncols:
# Plot figures in a single row if grid not specified
nrows = 1
ncols = len(figures)
else:
# check minimum grid configured
if len(figures) > nrows * ncols:
raise ValueError(f"Too few subplots ({nrows*ncols}) specified for ({len(figures)}) figures.")
fig = plt.figure()
# optional spacing between figures
fig.subplots_adjust(hspace=0.4, wspace=0.4)
for index, title in enumerate(figures):
plt.subplot(nrows, ncols, index + 1)
plt.title(title)
plt.imshow(figures[title])
plt.show()
Any grid configuration (or none) can be specified as long as the product of the number of rows and the number of columns is equal to or greater than the number of figures.
For example, for len(figures) == 10, these are acceptable
plot_figures(figures)
plot_figures(figures, 2, 5)
plot_figures(figures, 3, 4)
plot_figures(figures, 4, 3)
plot_figures(figures, 5, 2)
import numpy as np
def save_image(data, ws=0.1, hs=0.1, sn='save_name'):
import matplotlib.pyplot as plt
m = n = int(np.sqrt(data.shape[0])) # (36, 1, 32, 32)
fig, ax = plt.subplots(m,n, figsize=(m*6,n*6))
ax = ax.ravel()
for i in range(data.shape[0]):
ax[i].matshow(data[i,0,:,:])
ax[i].set_xticks([])
ax[i].set_yticks([])
plt.subplots_adjust(left=0.1, bottom=0.1, right=0.9,
top=0.9, wspace=ws, hspace=hs)
plt.tight_layout()
plt.savefig('{}.png'.format(sn))
data = np.load('img_test.npy')
save_image(data, ws=0.1, hs=0.1, sn='multiple_plot')

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