empty

Description

[] denotes the empty matrix. It is uniquely defined and has 0 row and 0 column, i.e. size([]) =[0,0]. The following convenient conventions are made:

[] * A = A * [] = []

[] + A = A + [] = []

[ [], A] = [A, []] = A

Matrix functions return [] or an error message when there is no obvious answer. Empty linear systems (syslin lists) may have several rows or columns.

Examples

s=poly(0,'s');
A = [s, s+1];
A+[], A*[]
A=rand(2,2);
AA=A([],1), size(AA)
svd([])
w=ssrand(2,2,2);
wr=[]*w;
size(wr), w1=ss2tf(wr), size(w1)

See also

• null — deletes a list component or a field of a structure, Mlist, or Tlist
• isempty — check if a variable is an empty matrix or an empty list
• emptystr — zero length string
• brackets — Concatenation. Recipients of an assignment. Results of a function
• operators — scilab operator names
• matrices — Scilab objects, matrices in Scilab

History