rank — Rank of a Matrix

rank calculates the rank of the argument matrix. The rank of a matrix is the number of non-zero singular values of that matrix. However since numeric computation introduces errors, the singular values are actually tested against a set tolerance value. The optional scalar argument, if present, specifies the tolerance, otherwise the default of the triple-product of the greater dimension of the argument, the 2-norm of the matrix and machine epsilon is used. $\Longrightarrow$ This is not an built-in function. This function is normally loaded on start-up from the rank.r file in the standard rlib directory. Use of the -r option, incorrectly setting the RLAB_LIB_DIR environmental variable, or modifying rank.r may make this function unavailable.