persistent

Persistent variable.

Syntax

• persistent variable_name
• persistent('variable_name')
• persistent variable_name1, ..., variable_nameN

Input argument

• variable_name - a string: variable name.

Description

persistent defines a variable defined by his name variable_name as persistent in a function.

Before to use a persistent variable, it is necessary to initializ value.

Examples

function to define:

function r = test_persistent_function()
 persistent calls;
 if isempty(calls)
    calls = 0;
 end
 disp(['nb calls to test_persistent_function: ', int2str(calls)]);
 r= calls;
 calls = calls + 1;
end

calls test_persistent_function

for i = 1:30
  r = test_persistent_function();
end

See also

clear, who, global.

History

Author

Allan CORNET