如何保存箭袋图

Question

Let me show you my code

array['fieldv'].shape

(112, 750, 750, 2)

and if I a plot an element, this image appear

%matplotlib inline
U, V  = array['fieldv'][10,:,:,0], array['fieldv'][10,:,:,1]
plt.quiver(U[::4,::4], V[::4, ::4])

Now my question is: how can I save in a directory all the quiver lots of the 112 elements? I show you my code that doesn't work

%matplotlib inline

i = 0
while i != len(array['fieldv'][0]):
    U, V  = array['fieldv'][i:,:,0], array['fieldv'][i,:,:,1]
    fig = plt.quiver(U[::4,::4], V[::4, ::4])

    filename = '/home/rr/workspace/TEST/OUTPUT/vectorf/'
    fig.savefig(filename + 'TEST_' + str(i) + '.png')
    i += 1

Answer 1

plt.quiver does not return a Figure instance (check type(fig) and you'll see that plt.quiver actually creates an instance of Quiver). The Quiver object does not have a savefig method and so fig.savefig will not work. However, you should just be able to swap the the fig.savefig command with plt.savefig .

As a more general comment I think it's more appropriate to use a for loop here, rather than a while statment. I'd do so as for i in range (array['fieldv'].shape[0]): . I also think .format is a bit neater: plt.savefig('{}TEST_{}.png'.format(filename, i)) .

Putting that altogether I'd do:

filename = '/home/rr/workspace/TEST/OUTPUT/vectorf/'

for i in range(array['fieldv'].shape[0]):
    U, V  = array['fieldv'][i:,:,0], array['fieldv'][i,:,:,1]
    Q = plt.quiver(U[::4,::4], V[::4, ::4])

    plt.savefig('{}TEST_{}.png'.format(filename, i))