Set size, background, and axes visibility in Matplotlib-CodePudding

I am trying to plot the following image (Red writing is for illustration only) for these points [[0, 0], [20, 10], [50, 50],[100, 50], [120, 120]] using matplotlib.

The expected result is as follows:

I tried this code

points = [[0, 0], [20, 10], [50, 50],[100, 50], [120, 120]]

# set image size
px = 1/plt.rcParams['figure.dpi'] 
plt.subplots(figsize=(271*px, 271*px))

ax = plt.gca()

# remove padding
ax.set_position((0, 0, 0, 0))

# set maximum and minimum values
ax.set_xlim([0, 270])
ax.set_ylim([0, 270])

# set background color
plt.axes().set_facecolor('black')

# make axis invisible
#plt.axis('off')

# plotting 
for i in range (len(points) - 1):
    plt.plot([points[i][0], points[i 1][0]], [points[i][1], points[i 1][1]], color="white")

plt.savefig('testplot.png')
plt.show()

But the resulted image is as follows

For research purposes, I need to make the image exactly follow these requirements:

Image size 271 px * 271 px
Without white padding
Maximum X and Y values are 270
Image background is black
One pixel between each step
Each point in the image represents a pixel
Invisible axes

CodePudding user response：

This might be what you are looking for:

points = [[0, 0], [20, 10], [50, 50],[100, 50], [120, 120]]
points_x = [i[0] for i in points]
points_y = [i[1] for i in points]

px = 1/plt.rcParams['figure.dpi']
fig = plt.figure(figsize=(271*px, 271*px))
plt.plot(points_x, points_y, color="white")
plt.axes().set_facecolor('black')
plt.xlim([0, 270])
plt.ylim([0, 270])
plt.show()

Splitting the data before plotting can safe you some trouble and adding elements to a 'simplified' version till something breaks is often a good idea.

CodePudding user response：

Finally, I found the solution. The whole requirements are covered as follows:


import matplotlib.pyplot as plt

points = [[0, 0], [20, 10], [50, 50],[100, 50], [120, 120]]
points_x = [i[0] for i in points]
points_y = [i[1] for i in points]

px = 1/plt.rcParams['figure.dpi']
fig = plt.figure(figsize=(571*px, 571*px), facecolor='black')

plt.plot(points_x, points_y, color="white")

plt.axis('off')

plt.xlim([0, 270])
plt.ylim([0, 270])

fig.subplots_adjust(
    top=1.0,
    bottom=0.0,
    left=0.0,
    right=1.0,
    hspace=0.2,
    wspace=0.2
)

plt.savefig('testplot.png')
plt.show()

The resulted image: