What does "ValueError: object too deep for desired array" mean and how to fix it?

Question:

I’m trying to do this:

h = [0.2, 0.2, 0.2, 0.2, 0.2]

Y = np.convolve(Y, h, "same")

Y looks like this:

screenshot

While doing this I get this error:

ValueError: object too deep for desired array

Why is this?

My guess is because somehow the convolve function does not see Y as a 1D array.

Asked By: Olivier_s_j

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Answers:

The Y array in your screenshot is not a 1D array, it’s a 2D array with 300 rows and 1 column, as indicated by its shape being (300, 1).

To remove the extra dimension, you can slice the array as Y[:, 0]. To generally convert an n-dimensional array to 1D, you can use np.reshape(a, a.size).

Another option for converting a 2D array into 1D is flatten() function from numpy.ndarray module, with the difference that it makes a copy of the array.

Answered By: user4815162342

np.convolve() takes one dimension array. You need to check the input and convert it into 1D.

You can use the np.ravel(), to convert the array to one dimension.

Answered By: Sandip Kumar

np.convolve needs a flattened array as one of its inputs, you can use numpy.ndarray.flatten() which is quite fast, find it here.

Answered By: NoSuchUserException

You could try using scipy.ndimage.convolve it allows convolution of multidimensional images. here is the docs

Answered By: jelde015