从 Matlab/Octave 到 matplotlib 可视化/比较 numpy arrays

Question

I'm new to python and matplotlib, and I'd like to visualise / compare 3 mfcc files stored as numpy arrays in txt format.
I have the Octave code below, and I'd like to know how it can be done using python/matplotlib.

Any help is much appreciated.

load /dir/k11.txt  
load /dir/t11.txt  
load /dir/a11.txt  

subplot(1,2,1);imagesc(j11);axis('xy');colormap(jet);colorbar;subplot(1,2,2);imagesc(t11);axis('xy');colormap(jet);colorbar;  

c=[k11(:,end),k11(:,1:end-1)];  
figure(1);  
Ncep=size(c,2)-1;  
a=real(fft([c,zeros(size(c,1),512-Ncep*2-1),c(:,end:-1:2)]'));  
imagesc(a(1:end/2,:));  
axis('xy');  
colormap(jet);  

c=t11;  
figure(2);  
Ncep=size(c,2)-1;  
a=real(fft([c,zeros(size(c,1),512-Ncep*2-1),c(:,end:-1:2)]'));  
imagesc(a(1:end/2,:));  
axis('xy');  
colormap(jet);  

c=a11;  
figure(3);  
Ncep=size(c,2)-1;  
a=real(fft([c,zeros(size(c,1),512-Ncep*2-1),c(:,end:-1:2)]'));  
imagesc(a(1:end/2,:));  
axis('xy');  
colormap(jet);

Answer 1

Obviously your example has externalities so I can't reproduce it directly, but in general here is an octave example and its equivalent python one using the image features you require.

in Octave

% Read an image from a url 
Url = 'https://raw.githubusercontent.com/utkuozbulak/singular-value-decomposition-on-images/master/data/grayscale_cat.jpg';
A   = imread( Url );

imagesc( A );      % Show image in 'colour-scaled' form
axis xy            % Reverse the origin of the y-axis
colormap( jet );   % Choose the jet colormap

in Python3

import urllib.request             # needed for reading urls
import matplotlib.pyplot as plt   # needed for imread/imshow
import matplotlib.colors as cl    # needed for colour-scaling

# Read an image from a url
Url = urllib.request.urlopen( 'https://raw.githubusercontent.com/utkuozbulak/singular-value-decomposition-on-images/master/data/grayscale_cat.jpg' )
A   = plt.imread( Url, 'jpg' )

plt.imshow( A,               # Create a pyplot 'image' instance
    norm = cl.Normalize(),   # Choose colour-scaled form
    origin = 'lower',        # Reverse the origin of the y-axis
    cmap = 'jet'             # Choose the jet colormap
)

plt.show()