Question

Right, so I’ve got a list of x values, y values and z values (which I think I converted into arrays?) which I want to make a surface plot, but it’s not working.

Here’s what I’m trying to do, you can ignore most of the code as it is pretty irrelevant – just look at the end where I have xdis, ydis and dist and where I’m trying to plot atm I’m getting ValueError: need more than 1 value to unpack :(. Help much appreciated.

from math import *
from numpy import *
import pylab
def sweep (v,p,q,r,s):
    a=.98

    for i in range (1, len(v)-1):
        for j in range (1, len(v)-1):
            c =0.0

            if i==p and j==q: c =1.0
            if i==r and j==s: c= -1.0
            v[i,j]=(v[i -1,j]+v[i+1,j]+v[i,j -1]+v[i,j+1]+c-a*v[i,j])/(4-a)

def main():
    from mpl_toolkits.mplot3d import Axes3D
    from matplotlib import cm
    from matplotlib.ticker import LinearLocator, FormatStrFormatter
    import matplotlib.pyplot as plt
    ydis=[]
    xdis=[]
    resis=[]
    for j in range(2,18):
        for i in range(2,18):
            v= zeros ((20,20),float )
            p=q=9
            r=i
            s=j
            dv =1.0e10
            lastdv =0
            count =0
            while (fabs(dv - lastdv)>1.0e-7*fabs(dv)):
                lastdv =dv
                sweep(v,p,q,r,s)
                dv=v[p,q]-v[r,s]
            resis.append(dv)
            xdis.append(r-p)
            ydis.append(s-q)

    X=array(xdis)
    Y=array(ydis)
    Z=array(resis)
    fig = plt.figure()
    ax = fig.add_subplot(111, projection='3d')
    ax.plot_wireframe(X,Y,Z)
    plt.show()
main()

Answer 1

plot_wireframe expects three 2D-arrays (X,Y,Z) as input. So,

after:

X=np.array(xdis)
Y=np.array(ydis)
Z=np.array(resis)

add:

X=X.reshape((-1,16))
Y=Y.reshape((-1,16))
Z=Z.reshape((-1,16))