Making copies of functions with different workspaces

How to call the same function in different workspaces?

I tried using handle but it doesn't work:

myaccum.m

function y = myaccum(x)
	persistent buf;
	if isempty(buf)
		buf = 0;
	end
	buf = x + buf;
	y = buf;
end

call.m

accum1 = @myaccum;
accum2 = @myaccum;

for i=1:10
	out1(i) = accum1(2);
	out2(i) = accum2(3);
end
display([out1; out2]);

Result:

>> call
     2     7    12    17    22    27    32    37    42    47
     5    10    15    20    25    30    35    40    45    50

Need:

>> call
     2     4     6     8    10    12    14    16    18    20
     3     6     9    12    15    18    21    24    27    30

Answer 1

[Matt J]

I recommend using a classdef, but this method using Nested Functions would also work:

function test

    accum1 = getAccum;
    accum2 = getAccum;
    
    for i=1:10
        out1(i) = accum1(2);
        out2(i) = accum2(3);
        
    end
    
    disp([out1; out2]);

end

function h=getAccum

    h=@myaccum;
   
    buf=0;

    function y = myaccum(x)
        buf = x + buf;
        y = buf;
    end

end

[Slava Razumov]

Thank you!

Answer 2

[Matt J]

Make myaccum a class instead

classdef myaccum<handle  %Must be put in myaccum.m
    
    properties
        buf=0;
    end
    
    methods

        function y = increment(obj,x)
            
            obj.buf=obj.buf+x;
            y=obj.buf;
            
        end
    end
end

and then

accum1 = myaccum;
accum2 = myaccum;

for i=1:10
	out1(i) = accum1.increment(2);
	out2(i) = accum2.increment(3);
end

disp([out1; out2]);

[Slava Razumov]

Hello.

Both of these methods stop working as the nesting level increases.

for example

function [y1, y2, y3, y4] = fouraccum(x1, x2, x3, x4)
	accum12 = @twoaccum;
	accum34 = @twoaccum;

	[y1, y2] = accum12(x1, x2);
	[y3, y4] = accum34(x3, x4);
end

function [y1, y2] = twoaccum(x1, x2)
	accum1 = myaccum;
	accum2 = myaccum;

	y1 = accum1.increment(x1);
	y2 = accum2.increment(x2);
end

since every time the class is called

accum1 = myaccum;

the buf is reset