Calling subfunctions from a loop

Question

MG 2015-11-1

0
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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/252199-calling-subfunctions-from-a-loop

编辑： Jan 2015-11-1

Hi, I am trying to get matlab to run certain loops based on conditions. In my primary function, my_factorial, I want to have the option of either calling a for loop to be executed, or a while loop. Both loops calculate the same thing- factorials- but I want to have the option of only calling one of them. So far I have the following and it isn't working. What is wrong with my primary function? Every time I specify an n in the command window, and an m, matlab runs through the entire thing which isn't what I want.

function f = my_factorial(n, m)

     if m == 'for_loop'
        f = fact1(n);
     else m == 'while_loop';
        f = fact2(n);
 end
end

function f = fact1(n); my for loop end

function f = fact2(n); my while loop end

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Answer 1

Jan 2015-11-1

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/252199-calling-subfunctions-from-a-loop#answer_198098

编辑：Jan 2015-11-1

在 MATLAB Online 中打开

The == operator performs an elementwise comparison. Then m == 'for_loop' must fail, if m and the string do not have the same number of elements. The error message (which should be included in a question in the forum) should tell this clearly.

Better:

if strcmp(m, 'for_loop')
  ...

or:

switch m
  case 'for_loop'
    ...

It is surprising to read, that Matlab "runs through the entire thing", because the original code should stop with an error. Anyway, the debugger is an excellent tool to find out, what's going on: http://www.mathworks.com/help/matlab/debugging-code.html