This function is not yet fully documented. This is a transcript of the text-formatted help.
bbcount Create a counting black-box operator. BB=bbcount(BB1) creates a black-box operator that counts the number of operations it has been used to compute. This is useful for debugging and benchmarking iterative algorithms. bbcount creates an object that keeps track of both matrix-matrix products and the equivalent numberof matrix-vector products. This count is shown by disp(BB) (just BB at the prompt), or it can be accessed with bbcountstat. bbcountreset can be used to reset a counters. bbclear must be used to remove an operator that includes a bbcount object. Otherwise you will be left with orphaned variables in the base workspace. For an example, see bbcountreset. Note 1: the object created by bbcount does not follow normal Matlab conventions. If a counter is copied, the copy refers to the same object. This behaviour is necessary to allow the object to be passed to functions (conceptually, Matlab always creates a copy), but it may be confusing. Note 2: it is difficult to implement bbcount efficiently in a clean manner. Ading a counter to a black-box matrix may slow down a computation noticably. See also bbcountstat, bbcountreset, bbclear.