colon

Description

Colon symbol : can be used to form implicit vectors. (see also linspace, logspace)

j:k

is the vector [j, j+1,...,k] (empty if j>k).

j:d:k

is the vector [j, j+d, ..., j+m*d]

The colon notation can also be used to pick out selected rows, columns and elements of vectors and matrices (see also extraction,insertion)

A(:)

is the vector of all the elements of A regarded as a single column.

A(:,j)

ys the j-th column of A

A(j:k)

is [A(j),A(j+1),...,A(k)]

A(:,j:k)

is [A(:,j),A(:,j+1),...,A(:,k)]

A(:)=w

fills the matrix A with entries of w (taken column by column if w is a matrix).

See Also

• matrix
• for
• linspace
• logspace