MATLAB: What’s a persistent variable???

persistent

really I'm confused by persistent variables!!!

please help me to know what are they and their applications???

Best Answer

A persistent variable retains its values between calls to the routine.

For example

function trial
    persistent times_called
    if isempty(times_called); times_called = 0; end  %never called before
    times_called = times_called + 1;
    if mod(times_called,10) == 0
      fprintf('Trial called %d times so far\n', times_called);
    end
    %now do the real work of the routine
    .....
end

The above is just one of many uses.

Related Solutions

MATLAB: Is the recursive function not exiting when I call return

Recursive functions can be tricky. Remember, calling "return" only returns for the most recent function.

See attached image.

Calling return when inside the fourth call of the recursive function, only exits that fourth call. The other three calls of the function are still running.

In some cases, it is better to use an iterative approach such as a for loop or while loop instead of a recursive approach.

MATLAB: Create a function from another function with less parameters

You can use an anonymous function.

addMe = @plus; % the plus function (equivalent of the + operator) accepts two inputs
addOne = @(x) addMe(x, 1); % accepts one input x and returns x+1
addMe(2, 3) % returns 5
addOne(2) % returns 3

Best Answer

Related Solutions

MATLAB: Is the recursive function not exiting when I call return

MATLAB: Create a function from another function with less parameters

Related Question