C1_W4 Linear Algebra

[Ayush_Hakhu]

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• Week 4

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• Description

  I am having issues with

  • center_data
  • get_cov_matrix

I am following same steps to do but I guess I am making mistake on some point or not considering can you please help out

{moderator edit - solution code removed}

[Deepti_Prasad]

Hello @Ayush_Hakhu

@Ayush_Hakhu

mean_matrix = np.zeros((rows,cols))
for x in range(cols):
    mean_matrix[:x] = np.mean(Y[:x])
# use np.reshape to reshape into a matrix with the same size as Y. Remember to use order='F'
# mean_vector = None
# mean_matrix = None

Use of for loop is not required

the first code line for this grader cell should
mean_vector = None where # use np.mean to get the vector of means, remember to pass the correct axis argument
then
mean_matrix = None # use np.repeat to repeat the mean vector n_observations times

Then calculate mean matrix by use np.reshape to reshape into a matrix with the same size as Y. Remember to use order=‘F’
mean_matrix =None

Then subtract mean_matrix from centre data. The operations are performed elementwise

@Ayush_Hakhu

cov_matrix_tran = np.transpose(X)@X

incorrect code, you are suppose to use np.dot and not np.transpose

@Ayush_Hakhu

xshape

that should be x.shape

Regards
DP

[Ayush_Hakhu]

Thanks! for helping it worked