For loop to count matrix elements

Question

Kyle 2014-3-14

0
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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/121539-for-loop-to-count-matrix-elements

回答： Jos (10584) 2014-3-14

Hi all i'm trying to use a for loop ( for an assingmnet) to run through a 5000 element matrix ( which I've downloaded manually) and determine which variables fall under certain conditions ( hopefully they're apparent in the code). i think i've set everything up right but I'm getting output for only about 3700 numbers. also, i noticed i'm not getting any output for "f"... if x(n) > 200... even though i have several values that fall under this category in my matrix. any idea why this isn't working? i feel like it should be.

 amount=0;
  amount1=0;
  amount2=0;
  amount3=0;
  amount4=0;
  amount5=0;
  amount6=0;
for n=1:length(x) 
    if x(n)>=0 && x(n)<= 30 
        amount=amount+1 ;
    elseif x(n) >=30 && x(n)<=80
        amount1=amount1+1 ;
    elseif x(n) >= 80 && x(n)<=130 
            amount2=amount2+1 ;
    elseif x(n) >= 130 && x(n) <= 150
        amount3=amount3+1;
    elseif x(n) >=150 && x(n)<=180 
            amount4=amount4+1 ;
    elseif x(n) >= 180 && x(n) x<=200 
        amount5=amount5+1 ;
    elseif x(n) >= 200 
        amount6=amount6+1 ;
    end
end
% a,b,c,d,e,f are used to display final count values
a=amount
b=amount2
c=amount3
d=amount4
e=amount5
f=amount6