I want to realize a colour plot of a matrix. The rules for this kind of plot are:
- if -5 <
my_matrix[i,j]
< 8 use white. - if 8 <
my_matrix[i,j]
< 20 use black. - if 20 <
my_matrix[i,j]
< 30 use red. - if
my_matrix[i,j]
> 30 use green.
Here is the code, as you can see the matrix is random. I have also printed a text plot in order to check if the print is correct.
import numpy as np
import matplotlib.pyplot as plt
from matplotlib import colors
Z_1 = 8
Z_2 = 20
Z_3 = 30
period = 5
size = 10
np.random.seed(1)
my_matrix = np.random.randint(-4,50,[period,size])
my_matrix[0,0] = 33
my_matrix[1,0] = 31
print(" ")
print(my_matrix.T)
print(" ")
bounds = [-5,Z_1,Z_2,Z_3]
cmap = colors.ListedColormap(['white', 'black','red','green' ]).with_extremes(over='green')
pm=plt.pcolormesh(my_matrix.T, cmap = cmap)
plt.colorbar(pm, boundaries = bounds ,extend = 'max', extendfrac='auto' ,ticks=bounds)
for i in range(len(my_matrix[:,0])):
for j in range(len(my_matrix[0,:])):
plt.text(i,j,str(my_matrix[i,j]), va='center_baseline', ha='left',color = 'blue')
#plt.clim(0, 31)
plt.gca().invert_yaxis()
plt.show()
I think the command .with_extremes(over='...')
is useful for this kind of plot.
Unfortunately I get the following picture. The green colour is not present and some bound are not respected (see my_matrix(0)(1) or my_matrix(1)(0)).
I want to have a plot with the aforementioned rules which has all the related colours in the colorbar, also taking into account those values greater than 30.
CodePudding user response: