An index can be any expression that results in a scalar or a vector. The
index expression is evaluated first, and the resultant values are truncated
to integers. For example, suppose x = [1;2;3;...;100]
, then:
=x[1:10:2] ! displays 1 3 5 7 9
=x[2.1;2.5;2.9] ! displays 2 2 2
y=[2:5] ! define Y to be 2 3 4 5
=x[y/2+3] ! displays 4 4 5 5
z=[2;3] ! define Z to be 2 3
=x[y[z+1]-2] ! displays 2 3
A variable index always starts at one (1
).
The LEN
function returns a scalar value equal to the total length of a vector. The
VLEN
function returns a vector whose nth element is the length
of the nth dimension of its argument.
VLEN
of a vector returns a vector of length 1
, while
VLEN
of a matrix returns a vector of length 2
.
Note: The CLEN
function returns a scalar value equal to the length of a string.