for

Purpose

Repeat statements a specific number of times.

for variable = expression
    statements
end

The general format is

for variable = expression
    statement
    ...
    statement
end

The columns of the expression are stored one at a time in the variable while the following statements, up to the end, are executed.

In practice, the expression is almost always of the form scalar : scalar, in which case its columns are simply scalars.

The scope of the for statement is always terminated with a matching end.

Assume n has already been assigned a value. Create the Hilbert matrix, using zeros to preallocate the matrix to conserve memory:

a = zeros(n,n)  % Preallocate matrix
for i = 1:n
    for j = 1:n
        a(i,j) = 1/(i+j -1);
    end
end

Step s with increments of -0.1

for s = 1.0: -0.1: 0.0,..., end

Successively set e to the unit n-vectors:

for e = eye(n),..., end

The line

for V = A,..., end

has the same effect as

for j = 1:n, V = A(:,j);..., end

except j is also set here.