被numpy meshgrid输出混淆

Question

Using Python 2.7 with miniconda interpreter. I am confused by what means ND coordinate in the following statements, and could anyone tell how in the below sample xv and yv are calculated, it will be great.

"Make ND coordinate arrays for vectorized evaluations of ND scalar/vector fields over ND grids, given one-dimensional coordinate arrays x1, x2,..., xn."

http://docs.scipy.org/doc/numpy/reference/generated/numpy.meshgrid.html

>>> nx, ny = (3, 2)
>>> x = np.linspace(0, 1, nx)
>>> y = np.linspace(0, 1, ny)
>>> xv, yv = meshgrid(x, y)
>>> xv
array([[ 0. ,  0.5,  1. ],
       [ 0. ,  0.5,  1. ]])
>>> yv
array([[ 0.,  0.,  0.],
       [ 1.,  1.,  1.]])

regards, Lin

Answer 1

xv,yv are simply defined as:

xv = np.array([x for _ in y])
yv = np.array([y for _ in x]).T

so that for every index pair (i,j) , you have

xv[i,j] = x[i]
yv[i,j] = y[j]

which is useful especially for plotting 2D maps.