Input and output of data in matrices

In the previous sections, we have assumed that the data are already present when an operation is executed. However, a matrix does not come with a specific set of values, except zeroes, so the values needed for the computation must come from somewhere else.

There are several types of values that are needed in computation:

• Application-specific or user-specified values stored in the memory or in files.
• Matrices filled with a constant.
• Identity matrices.
• Diagonal matrices.
• Functions evaluated for each element.

• Data in files
• Data in memory
• Constants
• The Identity matrix
• The diagonal matrix
• Element functions