Python : how can I concatenate scipy.sparse matrices?

Question

I saved 2 CSR matrices on the disk in .npy format. For running the classifier, I need to merge the CSR matrices. How can I concatenate CSR2 to CSR1?

Answer 1

The sparse library has hstack and vstack for concatenating matrices horizontally and vertically respectively. Look at the following code for the reference.

from scipy import sparse

data1 = np.load('filename1.npy').tolist()

data2 = np.load('filename2.npy').tolist()

merged_data = sparse.vstack((data1,data2), format='csr')  #merge the data

The above code will generate the merged data in CSR format.