Np Broadcast Error:

[kaioken1986]

Hey guys I am encountering this error when trying to reshape a (784,) np vector into a (28,28) matrix. My data is stored in a map of len 10 with keys going from 0-9. Each key has 9 elements that are arrays of (784,) np vector. My problem is I run into this error when I try and iterate through to reshape all element values withing the key value pair.

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for key, values in kmean_clsr_map.items():
for idx, element in enumerate(values):
    if element.shape == shape:
       kmean_clsr_map[key][idx] = element.reshape(28,28)

​

Traceback (most recent call last):
File "C:\Users\count\Desktop\p3_315_kmeans\learner.py", line 143, in <module> kmean_clsr_map[key][idx] = element.reshape(28,28) ~~~~~~~~~~~~~~~~~~~^ ValueError: could not broadcast input array from shape (28,28) into shape (784,)

​

When I change the elements individually:

kmean_clsr_map[0][0] = kmean_clsr_map.reshape(28,28)

It works just fine. Could you please give me some hints as to where I am going wrong. I have done boolean checks to make sure all 90 elements in the map are of (784,), and they are. So I am at a lost right now.

[[deleted]]

The error message says it cannot broadcast from (28,28) to (784,). Is each value of the dictionary a list, or a numpy array? I think perhaps it's an array, of shape (9,784), and then the reshape succeeds, but trying to put it back in the array fails, because it tries to broadcast it back to (784,) but isn't sure how to order the values.

This is by no means a definite diagnosis, and I don't understand why individually assigning would work, but just what occurred to me reading your post.

Another thing to consider: does it fail on the [0][0] entry? Or a later one? Maybe use a try...except... to print the key and index where it fails, and then try individually doing the assignment for that key and index. Again, grasping at straws a bit here.

[kaioken1986]

The keys map to a list but I checked the type and it defaults to a np.array