Loops

While loops

Syntax:

while expression
  statements
end

Statements between while and end are excuted while (as long as) expression is true.

For loops

Syntax:

for x = values
  statements
  ...
end

Statements between for and end are excuted for every column in values. In most cases, values are row vectors. It is roughly the same as

temp = values;
k = 1;
while k <= size(temp, 2)
  x = temp(:, k);

  statements
  ...

  k = k + 1;
end

Examples:

x = 0:0.1:10;
y = zeros(size(x));
for k = 1:numel(x)
  y(k) = sin(x(k));
end

M = [1 2 3 4; 5 6 7 8];
for x = M
  % x is a column of a matrix M
  disp(sum(x));
end % => results are 6, 8, 10, 12

The expression for loop values is evaluated only once, and cannot be changed.