Matplotlib scale

[Julien Hofmann]

Hi everyone,


I've created a code to run a 2D mapping using matplotlib from a .csv file.
I've tried to set the maximum color (red) of the scale as 80% of the maximum 
value and not as the maximum value of my .csv file.
Does someone know how to modify that?
I've tried different solution but it doesn't work.

Thanks

import os 
import matplotlib.pyplot as plt
import pandas as pd
import numpy as np
from matplotlib import colorbar, colors
import matplotlib.tri as tri
 
#os.chdir("C:/Users/Julien Hofmann/Desktop/Nano-indentation")
data = pd.read_csv("Cartographie.csv",sep=';')
 
nb_lignes=21
nb_colonnes=27
 
 
fig = plt.figure(figsize=(15,12))
ax = plt.subplot(1,1,1)
x=np.linspace(0,(data["x"][len(data["x"])-1]-data["x"][0])*1000,nb_colonnes)
y=np.linspace(0,(data["y"][len(data["y"])-1]-data["y"][0])*1000,nb_lignes)
X,Y=np.meshgrid(x,y)
 
 
z=np.array(data["Durete"])
triang = tri.Triangulation(data["x"], data["y"])
interpolator = tri.LinearTriInterpolator(triang, z)
Xi, Yi = np.meshgrid(x, y)
zi = interpolator(Xi, Yi)
cntr1 = ax.contourf(x, y, z.reshape(nb_lignes,nb_colonnes), levels=150, 
cmap="jet")
cbar = fig.colorbar(cntr1, ax=ax)
ax.axis('on')
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Re: Matplotlib scale

[Julien Hofmann]

Le lundi 5 avril 2021 à 21:50:49 UTC+2, David Lowry-Duda a écrit :

Thank you for your response!
I just tried it but it doesn't make what I want.

Bassically, I would like to not put any color for every values above 0.8 times 
the maximum value (ie. 488).
Hence, the ''maximum'' color (ie. red) would correspond to 488 and not to 610 
as currently. 
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Re: Matplotlib scale

[Julien Hofmann]

Thank you for your response, and thank you for the different tips concerning 
visualisation. I'll improve it. 

I've tried to put vmin and vmax in contourf(). It works but the values above 
80% of the maximum value still remain red which makes the cartography not 
really clear. 

I think I should in black, or white, every values above 80% of the maximum 
value. 
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