TypeError：“ float”对象在矩阵中不可下标

Question

I have this error:

"TypeError: 'float' object is not subscriptable"

This is the part of the code that displays the error:

nd_coord = random.uniform(npoints, 2)         
nd_coord[:,0] = nd_coord[:,0] * ((xmax - xmin) + xmin)   
nd_coord[:,1] = nd_coord[:,1] * ((ymax - ymin) + ymin)  
print (nd_coord)

Answer 1

I take it you've imported NumPy as from numpy import * and so random.uniform is the NumPy method. Its call signature is:

numpy.random.uniform(low=0.0, high=1.0, size=None)

So the way you're using it, it returns a single number (which can't be indexed). Perhaps you want:

nd_coord = np.random.uniform(size=(npoints,2))

To pick npoints pairs of random numbers on [0,1).