If you have N I-dimensional input vectors to classify into one of c independent classes, the size of the input matrix is
corresponding to a target matrix with N c-dimensional 0-1 unit sum vectors
From the info in the question,
c = 51
N = 51*300 = 15,300
Therefore the target matrix has columns from eye(51) with 50 zeros and the single "1" indicates the class.
However, it is not clear from the description what I (the size of the input vectors) is supposed to be.
Hope this helps
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