826 questions
0
votes
0
answers
12
views
Adding colorbar to imshow in matplotlib makes plot stick to the right [duplicate]
When i added a colorbar to an imshow plot within pyside6 application, the whole plot sticks to the right (see picture).
image of matrix that stick to the right
When there is no colorbar, the plot is ...
0
votes
0
answers
19
views
Imshow, colormesh and contourf with MODIS data
my problem is that the pcolormesh make the right thing with interplation artefacts and imshow lose the lat/lon grid as shown in the image.
is there a way to get an mesh image without artefacts?
Here ...
- 13
2
votes
1
answer
50
views
Syncing matplotlib imshow coordinates
I'm trying to create an image using networkx, save that image to use later, and then overlay a plot over top of it later. However, when I try to load the image in and make new points, the scale seems ...
- 454
3
votes
1
answer
76
views
wordcloud with 2 background colors
I generated this on wordcloud.com using one of the "themes".
I'd like to be able to do this with the python wordcloud library, but so far all I can achieve is a single background color (so ...
- 692
0
votes
1
answer
23
views
python to contour plot three different densities in 2D
I wanted to plot three 2d densities of n0, n1 and n2 using imshow() command in matplotlib and show their colorbars.
The densities are quite different and even when i normalize them the final image is ...
- 9
-1
votes
1
answer
225
views
OpenCV IMSHOW error when running even when provided all parameters
I am using OpenCV for my program but I am getting an error during the cv2.imshow command. My program is trying to process an MP4 video and crop the licence plates from the cars involved.
I am ...
- 1
0
votes
0
answers
71
views
How to automate placement of fig.suptitle properly when displaying wide images with imshow in matplotlib?
The issue is that fig.suptitle and ax.imshow (with wide images) do not work well together. I understand that there are some aspect ratio (or something) hurdles to overcome due to the image being wide ...
- 91
0
votes
1
answer
46
views
how to inlay a matplotlib imshow inside another
Here's a reprex
import urllib # to retrieve the file from the internet
from PIL import Image # to interpret the bytes as an image
import numpy as np # to work with arrays of numbers (the image is an ...
- 903
0
votes
1
answer
75
views
How to achieve such picture effect using python？
I'm drawing a heat distribution map using python. But I found that the pixels of other people’s pictures looked like the first, and mine looked like the second.
It seems that other people's pictures ...
- 31
0
votes
1
answer
55
views
Heatmap plot with weirdly shaped data
so I am trying to create a heatmap plot for x, y data that are shaped as following:
xs, ys, corrs = [], [], []
for x in np.linspace(0.1,5,25):
xs.append(x)
for y in np.linspace(0.01,x,25):
...
0
votes
0
answers
35
views
"Imshow" not showing in top of "scatter"
I am willing to plot two different things in one image. I want to see the evolution of some probabilities in time, together with a cone which limits their expansion. I plot the first one using scatter,...
0
votes
0
answers
25
views
How can I force plots to be the same size when the figsize setting does nothing in pyplot? [duplicate]
I wrote the following code:
import pandas as pd
import numpy as np
import matplotlib.pyplot as plt
import random
symetricArr=[[random.random() for i in range(100)] for j in range(100)]
asymetricArr=[[...
- 782
-5
votes
1
answer
396
views
how to use cv2.imshow()?
Code:
cv2.imshow('E:\Open_CV\opencv\images', img)
error:
error: OpenCV(4.9.0) D:\a\opencv-python\opencv-python\opencv\modules\highgui\src\window.cpp:1272: error: (-2:Unspecified error) The function ...
0
votes
0
answers
85
views
The kernel appears to have died. It will restart automatically. whenever i try to run the plt.imshow() and plt.show() function in jupyter notebook
import cv2
import matplotlib.pyplot as plt
import tensorflow as tf
from tensorflow.keras.preprocessing.image import load_img, img_to_array
#load model using tensorflow
model = tf.keras.models....
2
votes
0
answers
202
views
Corrupted image when saving imshow as PDF with matplotlib
I have been trying to save an imshow figure as a PDF, but when I try to open it up in my PDF reader (Acrobat Reader DC) it says "Insufficient data for an image" and refuses to display the ...
- 21
0
votes
0
answers
43
views
Heatmaps with imshow not displaying x axis properly
I am attempting to create a heatmap using data from an Excel file. The excel file has multiple sheets and in each sheet there is a column with 'Z Score Times', which are the times I want on the X axis ...
- 1
0
votes
0
answers
153
views
Google Colab: On-click interactive plots not working
I'm trying to use this snippet, which works as intended locally, in Google Colab. The snippet basically set to NaN a pixel value on click. Google Colab does show correctly the image but if I click on ...
- 1
0
votes
1
answer
90
views
imshow defaults to inverted y axis, can't be flipped using invert_yaxis [duplicate]
Whenever I generate a graph in matplotlib, the axis seems to be inverted. As an example, I created a figure from an array of 0s:
dims = [100,100]
square = np.zeros(dims)
plt.imshow(square)
This ...
- 23
0
votes
1
answer
102
views
TypeError when using cv2.rectangle in Python OpenCV
this is my code
colors = [(245,117,16), (117,245,16), (16,117,245)]
def prob_viz(res, actions, input_frame, colors):
output_frame = input_frame.copy()
for num, prob in enumerate(res):
...
- 1
-2
votes
1
answer
89
views
opencv non-active application, window Error when i tried "imshow()"
my xcode error image
[CODE]
#include <iostream>
#include <sstream>
#include <opencv2/opencv.hpp>
using namespace std;
using namespace cv;
int main(){
cout << "openCV ...
1
vote
0
answers
42
views
Washed out colors when reproducing 2017 figure [duplicate]
In April 2017 I used the following code to produce the following figure:
plt.clf()
plt.imshow(result, cmap = 'hot', aspect = 'equal')
plt.colorbar()
plt.axis('off')
plt.savefig('p1....
- 11
0
votes
0
answers
143
views
Adding color bar to 1D heatmap [duplicate]
I have found an excellent answer from Creating a 1D heat map from a line graph but I need a color reference/side bar to show what numerical values each color represents.
There is a comment asking this ...
- 6,063
0
votes
0
answers
111
views
How to read .png file with matplotlib to not lack information? [duplicate]
I have created a png file with matplotlib. When opened in a Viewer it shows all the parts of the graph.
However, when reading the image with matplotlib, only the coordinate system is shown, not the ...
- 53
0
votes
2
answers
350
views
Make heatmap have the same axes size [duplicate]
This is a sample code. Here, xlim = (0,2) and ylim = (0,5). I want to keep it that way (different limits) while figuring out a way to make the x-axis and y-axis the same size.
import matplotlib.pyplot ...
0
votes
0
answers
104
views
imshow uses a seemingly random background color
I am trying to use imshow(), with categorical data. But I cannot reliably control the colors used. This is my code (inspired in the solution provided here
from random import choice
import matplotlib....
- 775
0
votes
2
answers
72
views
Reduce space between subplots [duplicate]
Do you know how to reduce the space between these plots?
fig, axs = plt.subplots(2)
axs[0].imshow(np.random.randint(0,15,size=(70,714)))
axs[1].imshow(np.random.randint(0,15,size=(70,714)))
plt.show()
...
3
votes
1
answer
120
views
imshow with x-axis as log scale is not equally-spaced
I am using pcolor to generate the following plot (code below). It has a colorbar in log scale and the x-values are in log-scale too. The problem is that the rectangles in this plot have different ...
- 698
0
votes
0
answers
24
views
plt.savefig behaviour in eps mode for nan type using imshow [duplicate]
I am trying to save an image using plt.imshow and plt.savefig by inputting a certain 2D array that happens to contain NaNs. When I call plt.show() the NaNs map to white but when saved to an eps file ...
- 31
1
vote
1
answer
753
views
How to plot a FITS image with world coordinates of RA DEC on galactic coordinates
I use the following code to plot a fits image with ra dec wcs onto a galactic coordinate:
import matplotlib.pyplot as plt
from astropy.io import fits
from astropy.wcs import WCS
fig = plt.figure()
...
- 11
0
votes
1
answer
116
views
imshow doesn't show the correct RGB values [duplicate]
I'm confused why my canvas class produce only 255 colors that is colors that are the pure red in this case.
Although my code specifies darker tones of red for the colors of the different pixels, the ...
0
votes
2
answers
466
views
How to adjust the scale of imshow plots to keep y axis constant in subplot?
I have several numpy arrays I am plotting with imshow. They all have the same vertical size but different horizontal sizes. I would like to adapt the aspect to be non-scalar and proportional to my ...
- 1
2
votes
2
answers
502
views
Plotting a Pandas DataFrame with RGB values and coordinates
I have a pandas DataFrame with the columns ["x", "y", "r", "g", "b"] where x and y denote the coordinates of a pixel and r, g, b denote its RGB value. ...
- 652
0
votes
1
answer
190
views
Align axes of imshow with axes of graph in the picture
I would like to plot on top of a picture of a graph from a paper.
I plot the picture with a simple imshow:
import matplotlib.pyplot as plt
import matplotlib.image as mpimg
img = mpimg.imread('...
- 129
0
votes
1
answer
514
views
Plot a Python Matplotlib imshow (heatmap) from a dictionary of lists
I have a dictionary of lists:
dictA = {"A": [1,2,3], "B": [4,5,6], "C": [7,8,9]}
I want to display the data as a heatmap using the Matplotlib imshow. A, B and C run ...
- 1,089
-2
votes
1
answer
292
views
Matplotlib imshow is ignoring cmap, vmin, vmax for ax.imshow subplots [closed]
I am trying to make subplots of small images of data and I am finding it completely impossible to adjust the cmap/vmin/vmax for any of these images. No matter what I can't figure out how to change the ...
0
votes
1
answer
56
views
How can I draw a contour for a piecewise function with pyplot.imshow
My function is z = (x - 1) **10 + 5*(x - 1)**5*(y - 1)**5 + (y - 1)**10. However, the contour can't show clear about negative value because of large positive value.
So I just need to show positive ...
- 2,573
0
votes
1
answer
20
views
How to extract specific condition values in python np.array without changing the shape
Range value of my image data is -0.3 ~ 28.25 and image shape was like this.
D1 = data1
D1 = D1[0, 0, ...]
D1 = data1 -> shape : (1,1,512,512)
D1 = D1[0, 0, ...] -> shape: (512,512)
Because, ...
- 13
0
votes
0
answers
58
views
I wonder why range of spectral index map by imshow is different with theoretical value
From fits file I got D1 and D2 data.
min and max value of D1 and D2 is like this
Since I'm trying to get spectral index value which formula is like this
I made my code like this
[D1 is flux data ...
- 13
0
votes
1
answer
108
views
How to create FuncAnimation (matplotlib) animation from plt.imshow and animate text in double for loop?
LONG POST: I know many posts are available on StackOverflow on a similar topic, but none worked for me so far. The animation is either not fast enough, or the text is animated (not how I want), but ...
- 147
0
votes
0
answers
61
views
opencv imshow() didnt work on windows 10,but works on mac why?
import cv2
img = cv2.imread('lena.jpg',1)
cv2.imshow('image',img)
cv2.waitKey(0)
cv2.destroyAllWindows()
cv2.waitKey(1)
No image is displayed while running the program above on windows10 (python 3.10,...
0
votes
1
answer
170
views
matplotlib, imshow not having witespace between axes in grid plot
I want a grid figure with m rows and n columns to be displayed sharing both x and y axis between subplots, and no whitespace between them. This is easy to achieve with simple plot in matplotlib, as ...
- 93
0
votes
0
answers
192
views
How to create a logarithmic scale for the x and y axis of a heat map with Python
Im having some issues creating a heatmap using plt.imshow() with specific axes that I want to display in a logarithmic scale. I tried different methods, but the image doesn't seem to work when i try ...
- 1
0
votes
1
answer
92
views
Why isn't imshow displaying correctly when using custom ticks?
I am trying to plot heatmap with average values with x and y axes denote physical parameters.
import csv
import matplotlib.pyplot as plt
from scipy import stats
import numpy as np
#......................
- 41
0
votes
2
answers
329
views
Draw contour around binary mask image in Python
I have a binary mask of the Antarctic ice sheet with pixels 0 = no ice sheet and 1 = ice sheet. How can I create a contour around the ice sheet pixels so that it creates an edge around the mask using ...
- 361
0
votes
1
answer
157
views
imshow with twinx that is also aligned with tiles
There is a thread where the question was to add an automatically labelled twinx to Matplotlib's imshow. The result was:
However, I would like the ticks on the second y-axis to be 1. manually settable ...
- 415
0
votes
0
answers
85
views
use of matplotlib.imshow() without "Clipping input data to the valid range"
I'm using matplotlib.imshow() with students to learn basic image processing. But if a student make an error, i would like python to show a warning instead of correcting it automatically.
For exemple : ...
1
vote
1
answer
79
views
How to plot multiple color lists from pandas in subplots with imshow
I'm looking to visualize the colors of music releases per genre.
I'm using the below code. However, the issue is that it's not showing the colors grouped per genre on individual rows. It seems like it'...
- 97
3
votes
1
answer
731
views
plt.imshow() of a single color image showing as black
I am trying to show a light-gray image using plt.imshow(), but the image turns out black.
I tried:
import matplotlib.pyplot as plt
import numpy as np
test_image = np.zeros((3871, 2484))
test_image....
- 101
0
votes
0
answers
46
views
Why does my matplotlib-plotted image looks almost completely white? [duplicate]
I am trying to plot .npy-files containing 3d arrays (values in range from -90 to 315) with matplotlib and I am constantly getting an almost completely white image, with only a few colorful spots.
This ...
- 25
1
vote
0
answers
76
views
How to change figsize keeping imshow aspect='equal'?
Is there a way to change the figsize of a matplotlib figure after drawing an image with ax.imshow()?
I have a numpy array of size (10, 100) (let's say) and I want to plot it with ax.imshow(). It ...
- 11