The comparison functions used for matrix processing are needed for finding more information about a matrix or group of matrices from the point of view of: the matrix type, its elements type or the apparition number of a key in the matrix.

The function symmet checks if a matrix is a square or a symmetrical one. It gets as entry parameters the matrix’ lines and columns numbers, which are n and m, and the matrix X. The matrix is defined static. The function returns the address of an integer variable, *er, where it writes 1 if the matrix is symmetrical or 0 if the matrix isn’t symmetrical. Also it verifies if the matrix is a square one and it writes 0 at the integer variable’ address if the condition isn’t fulfilled.
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Other posts on this topic:

• C and C++ library of functions and procedures for matrix (bidimensional arrays) processing – Introduction (contains the C/C++ library source code)
• C and C++ library of functions and procedures for matrix (bidimensional arrays) processing – Read and Write functions

The mathematical functions uses the matrices as operands in different math operations. The operations with matrices described in this chapter are adding, multiplying, transposing, subtracting and inverting. Also here are some arithmetical operations with linear matrices like adding, subtracting, multiplying and transposing. For example, two linear matrices sum is obtained after transforming the matrices in one-dimensional arrays and adding them. In the same way are done the others operations.

In this post are described the functions that are doing those computations. Both variants of defining a matrix, the static method and the dynamic one, are used. Read the rest of this entry »