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 inv([]) =[]

det([])=cond([])=rcond([])=1, rank([])=0

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

• matrices — Scilab objects, matrices in Scilab
• poly — polynomial definition
• string — conversion to string
• boolean — Scilab Objects, boolean variables and operators & | ~
• rational — Scilab objects, rational in Scilab
• syslin — linear system definition

History