Are examples in columns and features in rows?

Course Q&A Deep Learning Specialization Neural Networks and Deep Learning
1

Can you approve is is correct? I was sure that colums should be feature in most part of cases and rows — numbers of examples. Or is it out-of-cases examples maybe to multiply with W matrix wich rows are weights of the example? Can you explain more clearly this topic?

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2

The convention for neural networks in the Deep Learning Specialization is that,

In the X matrix,

  • a column represents a sample;
  • a row represents a feature.

In the W matrix of the l-th layer:

  • a column represents the number of features from (or neurons in) the previous, l-1-th, layer,
  • a row represents a neuron of the l-th layer itself

This is the convention for neural networks in the Deep Learning Specialization. You can see a different convention in other places.

Raymond