length

Arguments

M

matrix (usual or polynomial or character string) or list

n

integer or integer matrix

Description

For usual or polynomial matrix n is the integer equal to number of rows times number of columns of M. (Also valid for M a boolean matrix)

For matrices made of character strings (and in particular for a character string) length returns in n the length of entries of the matrix of character strings M.

The length of a list is the number of elements in the list (also given by size).

The length of a mlist is by default the number of elements in the mlist, but you can overload it (see example).

length('123') is 3. length([1,2;3,4]) is 4.

WARNING : length of a sparse matrix returns the max of dimensions and not the product of the dimensions. (example : length(sparse(eye(12,2))) returns max(12,2) and not 24)

please use size(...,'*') with sparse matrix.

Examples

length([123 ; 456 ])
length(['hello world',SCI])

a = mlist(["myMlistT" "field1" "field2"],"aexample","bexampleb");
length(a) 
// returns 3 default behaviour if length not overloaded for MList

// we create an overload function for MList of type myMlistT
function r=%myMlistT_length(M)
  r = length(M.field1)
endfunction

length(a) 
// returns 8 result of length(a.field1)

See Also

• size — taille d'un objet

History