I want to plot a 2d condition function, and the code as below:

```
from numpy import exp,arange
from pylab import meshgrid,cm,imshow,show
def z_func(x,y):
zParity = x % 2
nParity = y % 2
if zParity == 0 and nParity == 0:
return x+y+1
elif zParity!=0 and nParity!=0:
return x+y-1
else:
return x+y
x = arange(1,100,1)
y = arange(1,100,1)
X,Y = meshgrid(x, y) # grid of point
Z = z_func(X, Y) # evaluation of the function on the grid
im = imshow(Z,cmap=cm.RdBu) # drawing the function
show()
```

I get an error: ValueError: The truth value of an array with more than one element is ambiguous. Use a.any() or a.all()

How can I change the code to work?

### >Solution :

Try this:

```
from numpy import exp,arange
from pylab import meshgrid,cm,imshow,show
import numpy as np
def z_func(x,y):
zParity = x % 2
nParity = y % 2
if np.all((zParity == 0, nParity == 0)):
return x+y+1
elif np.all((zParity!=0, nParity!=0)):
return x+y-1
else:
return x+y
x = arange(1,100,1)
y = arange(1,100,1)
X,Y = meshgrid(x, y) # grid of point
Z = z_func(X, Y) # evaluation of the function on the grid
im = imshow(Z,cmap=cm.RdBu) # drawing the function
show()
```

This is what I get after running the code (I hope I have understood what you want to get, otherwise I will edit my answer accordingly):