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Exercise

Non-negative matrix factorization

It's possible for one matrix to have two equally close factorizations where one has all positive values and the other has some negative values.

The matrix M has been factored twice using two different factorizations. Take a look at each pair of factor matrices L and U, and W and H to see the differences. Then use their products to see that they produce essentially the same product.

Instructions

100 XP
  • Use print() to view the L and U matrices. Notice that some values in matrices L and U are negative.
  • Use print() to view the W and H matrices. Notice that all values in these two matrices are positive.
  • The L and U matrices and W and H matrices have been multiplied together to produce the LU and WH matrices respectively. Use getRMSE(product_matrix, original_matrix) to see how close LU is to M compared to how close WH is to M. Are they similar?