Hi everyone,

I am not that familiar in using the function tricontourf. I would need help understanding what I am doing wrong.
So basically, from an external FEM software, I am getting datas from a line of nodes:

• x coordinates of these nodes (that I need to plot in the x axis) X_coord.csv
• time steps of the simulation (that I need to plot in the y axis) time.csv
• stress (that should give the color of the plot) stress.csv

I managed to get a first glimpse of what I want my final plot to look like using: matplotlib.pyplot.scatter. That gives:

However, I would the plot to be continuous and for that I tried to use: matplotlib.tri.tricontourf. That gives:

Do you from where are coming this pattern of vertical lines? Do you know how can I improve my basic code to have something that looks better? The big yellow part (that should be white) in the tricontourf around 0.04 is not that problematic since I can plot the two parts (left and rigth parts) separately but if you have any improvement on that side, you are welcome!

Here is my code:

import matplotlib.pyplot as plt
import numpy as np

X=np.loadtxt(r'....\X_coord.csv')
Y=np.loadtxt(r'....\time.csv')
S33=np.loadtxt(r'....\stress.csv')

fig, ax1 = plt.subplots(nrows=1)
test=ax1.tricontourf( X ,Y ,S33 ,levels=1000, cmap="viridis")
ax1.scatter(X,Y,c=S33,cmap='viridis',vmin=-5000, vmax=100,s=5)

fig.colorbar(test, ax=ax1)
ax1.set(xlim=(-0.003, 0.08), ylim=(-4e-10, 1.3e-8))

Thanks in advance,
Cheers