Contour graph in python
contour, matplotlib, python
Solution
You can do this using the `levels` keyword in contourf.
import numpy as np
import matplotlib.pyplot as plt
fig, axs = plt.subplots(1,2)
x = np.linspace(0, 1, 100)
X, Y = np.meshgrid(x, x)
Z = np.sin(X)*np.sin(Y)
levels = np.linspace(-1, 1, 40)
zdata = np.sin(8*X)*np.sin(8*Y)
cs = axs[0].contourf(X, Y, zdata, levels=levels)
fig.colorbar(cs, ax=axs[0], format="%.2f")
cs = axs[1].contourf(X, Y, zdata, levels=[-1,0,1])
fig.colorbar(cs, ax=axs[1])
plt.show()
You can change the colors by choosing and different colormap; using vmin, vmax; etc.
Problem
How would I make a countour grid in python using `matplotlib.pyplot`, where the grid is one colour where the `z` variable is below zero and another when `z` is equal to or larger than zero? I'm not very familiar with `matplotlib` so if anyone can give me a simple way of doing this, that would be great. So far I have: ``` x= np.arange(0,361) y= np.arange(0,91) X,Y = np.meshgrid(x,y) area = funcarea(L,D,H,W,X,Y) #L,D,H and W are all constants defined elsewhere. plt.figure() plt.contourf(X,Y,area) plt.show() ```