Running two MATLAB programs at the same time

Hi, I have a function in Matlab which depends on an input N. I need to run function(2),function(3),function(4),function(5) and perhaps also try other values of N. Each of these runs takes about two hours. I could run one after the other, but it would be much more efficient if I could just run them at the same time. Each run is independent of the other, so this should be doable, right?. I want to do the same one does when one runs a script in bash with nohup ./script.sh &, so you can send other scripts. How can I do this in Matlab?

Thanks

Answer 1

[KSSV]

funcs1 = {@fun1, @fun2} ;   % let fun1, fun2 be two functions 
arguments = {inp1,inp2 ;inp1,inp2} ;   % write the inputs of each function 
solutions = cell(1,2);                 % initialize the solution 
% use of parfor 
parfor ii = 1:2
      solutions1{ii}=funcs1{ii}(arguments1{ii,:});
end
M = solutions1{1} ; N = solutions1{2} ;   % assign the results

[NGOC TAM LAM]

When I run code with

funcs = {@choose3DirRolling_Right, @choose3DirRolling_Left} ;   % let fun1, fun2 be two functions 
arguments = {updatedRightCoord,oxyzRightArrow;updatedUpCoord,oxyzUpArrow} ;   % write the inputs of each function 
solutions = cell(1,2);                 % initialize the solution 
% use of parfor 
parfor ii = 1:2
      solutions{ii}=funcs{ii}(arguments{ii,:});
end

Error is Too many output arguments.

Can you helps please!

[Walter Roberson]

How many inputs does choose3DirRolling_Right have? How many inputs does choose3DirRolling_Left have?

[NGOC TAM LAM]

choose3DirRolling_Right(updatedRightCoord,oxyzRightArrow);
choose3DirRolling_Left(updatedUpCoord,oxyzUpArrow);

There are two functions with two input vars as I put in arguments.

[NGOC TAM LAM]

I created the simple program as below but it is the same error.

clc

x = 0:0.01:10;
y1 = sin(x);
y2 = cos(x);

funcs = {@func1, @func2} ;   % let fun1, fun2 be two functions 
arguments = {x y1;x y2} ;   % write the inputs of each function 
solutions = cell(1,2);                 % initialize the solution 

% use of parfor 
parfor ii = 1:2
      solutions{ii}=funcs{ii}(arguments{ii,:});
end

with two functions:

function func1(x,y)
    plot(x, y), xlabel('x'), ylabel('Sin(x)'), title('Sin(x) Graph'),
    grid on, axis equal
end

%----------------
function func2(x,y)
    plot(x, y), xlabel('x'), ylabel('Cos(x)'), title('Cos(x) Graph'),
    grid on, axis equal
end

[Walter Roberson]

Your functions do not return any value but you try to assign their lack of value to solutions variable.

[NGOC TAM LAM]

Thanks @Walter Roberson. Now I got the right answer. It should be return value for each function. But in the case of without the output value, how can I run it?

Answer 2

[Walter Roberson]

You can use the Parallel Computing Toolbox, with batch() or parfeval()

Note: unless you configure specially, each worker would have access to one physical core. That can be a problem if your routines do a lot of mathematical calculations with large arrays: such calls are normally sent to an optimized library that automatically uses multiple threads. If this applies to your program, then running in parallel can end up taking longer than running individually.