Function using for loop

Question

Sayanta 2012-5-31

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/39981-function-using-for-loop

Hi All,

I want to write a function using a for loop but the function will do the same functionality. The function is shown below

How can I do that any tips ?

Here is function

f unction [state1,state2] = stat(x)

% for previous state
if (x(1) <= 5)
    state1 = 1;
end
if (x(1) > 5 &&  x(1) <= 10)
    state1 = 2;
end
if (x(1) > 10 &&  x(1) <= 15)
    state1 = 3;
end
if (x(1) > 15 &&  x(1) <= 20)
    state1 = 4;
end
if (x(1) > 20 &&  x(1) <= 25)
    state1 = 5;
end
if (x(1) > 25 &&  x(1) <= 30)
    state1 = 6;
end
% for current state
if (x(2) <= 5)
    state2 = 1;
end
if (x(2) > 5 &&  x(2) <= 10)
    state2 = 2;
end
if (x(2) >10 &&  x(2) <= 15)
    state2 = 3;
end
if (x(2) > 15 &&  x(2) <= 20)
    state2 = 4;
end
if (x(2) > 20 &&  x(2) <= 25)
    state2 = 5;
end
if (x(2) > 25 &&  x(2) <= 30)
    state2 = 6;
end

Many Thanks in advance

Sayanta

2 个评论
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Oleg Komarov 2012-5-31

you can actually avoid a for loop and use histc()

Oleg Komarov 2012-5-31

From my perspective this user has asked the same question for the 6th time, got an answer and did not interact with the contributors to get to the bottom of the problem. At this point I suggest to invest time with other users of the forum unless Sayanta starts giving some feedback.

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Answer 1

Andrei Bobrov 2012-5-31

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https://ww2.mathworks.cn/matlabcentral/answers/39981-function-using-for-loop#answer_49589

在 MATLAB Online 中打开

x = unifrnd(3,36,20,1);
[state2,state2 ] = histc(x,[-inf,5:5:30] + eps(100));

or

k = [-30:5:-5 inf]
[j1,j1] = histc(-x,k )
n = numel(k)
state2 = rem(abs(j1-n),n)

1 个评论
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Walter Roberson 2012-5-31

As a usage note: andrei has used these mechanisms of adding eps() or negating the values involved, in order to compensate for the fact that histc() defines its bins as a <= x < b whereas your request was for a < x <= b . If your boundaries can be switched so that (for example) _exactly_ 25 is state 6 instead of state 5, then histc() can be used directly with no fiddling.

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Answer 2

Geoff 2012-5-31

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链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/39981-function-using-for-loop#answer_49637

在 MATLAB Online 中打开

There's a pattern here...

state1 = max( ceil(x(1) / 5), 1 );
state2 = max( ceil(x(2) / 5), 1 );

Just as a point on style... if you want to write a bunch of if statements for a continuous range, do this:

if x(2) <= 5
  state2 = 1;
elseif x(2) <= 10
  state2 = 2;
elseif x(2) <= 15
  state2 = 3;
elseif % etc etc
  % etc etc
else
  state2 = NaN;  % What happens if out of range?
end