Does it have a statement for replacing repeated multiple if and elseif statements?

Question

Jeah MK 2022-2-28

0
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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1660290-does-it-have-a-statement-for-replacing-repeated-multiple-if-and-elseif-statements

回答： David Hill 2022-2-28

I have a code:

a = 0:0.001:1; 
b = 0.03*sin(a);
for i = 1:length(a), 
    d = 0; 
    if b(i) <= 0.02; 
        if 0 < b(i) <= 0.1*pi/180
            c = 0:0.1*pi/180:10*pi/180; 
        elseif 0.1*pi/180 < b(i) <= 0.2*pi/180
            c = 0.1*pi/180:0.1*pi/180:10*pi/180;
        elseif 0.2*pi/180 < b(i) <= 0.3*pi/180
            c = 0.2*pi/180:0.1*pi/180:10*pi/180;
        elseif 0.3*pi/180 < b(i) <= 0.4*pi/180
            c = 0.3*pi/180:0.1*pi/180:10*pi/180;
        elseif 0.4*pi/180 < b(i) <= 0.5*pi/180
            c = 0.4*pi/180:0.1*pi/180:10*pi/180;
        elseif 0.5*pi/180 < b(i) <= 0.6*pi/180
            c = 0.5*pi/180:0.1*pi/180:10*pi/180; 
        elseif 0.6*pi/180 < b(i) <= 0.7*pi/180
            c = 0.6*pi/180:0.1*pi/180:10*pi/180;
        elseif 0.7*pi/180 < b(i) <= 0.8*pi/180
            c =  0.7*pi/180:0.1*pi/180:10*pi/180;
        elseif 0.8*pi/180 < b(i) <= 0.9*pi/180
            c = 0.8*pi/180:0.1*pi/180:10*pi/180;
        elseif 0.9*pi/180 < b(i) <= 1*pi/180
            c = 0.9*pi/180:0.1*pi/180:10*pi/180;
        end
    end
    
    for k = 1:length(c), 
        d = d + b(1,i)*c(1,k);
    end
    e(1,i) = d; 
end 

I wonder if there is any way to get the same result by replacing the repeated elseif statement.

Thank you!

3 个评论
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Jeah MK 2022-2-28

@DGM sorry that the code is not clear. I modified it and the full code for my purpose. Thank you!

Cris LaPierre 2022-2-28

在 MATLAB Online 中打开

Note that your conditional statements are not robust. Consider the following.

0 < 5 < 6
ans = logical
   1
0 < -5 < 6
ans = logical
   1

Both statements evaluate as true, though you likely intend for the 2nd one to be false. I would be more explicit with how I write these.

0 < -5 && -5 < 6
ans = logical
   0

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Answer 1

David Hill 2022-2-28

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1660290-does-it-have-a-statement-for-replacing-repeated-multiple-if-and-elseif-statements#answer_906345

在 MATLAB Online 中打开

a = 0:0.001:1; 
b = 0.03*sin(a);
interval=0:.1*pi/180:pi/180;
[~,~,idx]=histcounts(b,interval);
b=b(idx~=0);
for k=1:length(b)
    e(k)=sum(b(k)*((idx(k)-1)*.1*pi/180:.1*pi/180:10*pi/180));
end