Help using loop and range interval

Question

Damilola 2014-11-10

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/162062-help-using-loop-and-range-interval

评论： Damilola 2014-11-10

I have a wind speed data (v) as a column vector that varies at different instant, I want to create a model = 0.5*1.29*9.62*jan.^3*cp; that uses different coefficient (cp) at a particular range of wind speed v. If v is less than 3, cp = 0, if v falls in a range between 3 and 10 (inclusive) then cp = 0.4, if v falls in a range greater than 10 and less or equal to 14 cp = 0.2 and if v is greater than 14 but less than 25 cp = 0.1 and if v is greater than 25 cp = 0.001. I want to create this model and have a final result of column vector that I will plot. Below is a loop that I tried to write.This is my first time trying to create a loop and also first time trying to have a range interval in matlab code. When I run this code I get an error message "Operands to the and && operators must be convertible to logical scalar values." Please I need help as I don't know how to solve this error. Thanks

jan = airport_spd;
model = 1.29*9.62*jan.^3*cp;
    for v = jan
        if v < 3
            cp= 0;
            model = 0.5*1.29*9.62*v.^3*cp;
        elseif v >=3 & v<=10
            cp = 0.4;
            model = 0.5*1.29*9.62*v.^3*cp;
        elseif v > 10 && v<= 14
            cp = 0.2;
            model = 0.5*1.29*9.62*v.^3*cp;
        elseif v >14 && v < 25
            cp = 0.1;
            model = 0.5*1.29*9.62*v.^3*cp;
        elseif v > 25
            cp = 0.001;
            model = 0.5*1.29*9.62*v.^3*cp;
        end
    end

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Andrei Bobrov 2014-11-10

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/162062-help-using-loop-and-range-interval#answer_158371

编辑：Andrei Bobrov 2014-11-10

在 MATLAB Online 中打开

v = randi([0,30],60,1); % Let your data
k0 = 0.5*1.29*9.62;
c = [0;.4;.2;.1;.001];
k = [-inf;3;10;14;25;inf];
[~,b] = histc(v,k);
model = k0*v.^3.*c(b);

with loop for..end

n = numel(v);
model = zeros(n,1);
k0 = 0.5*1.29*9.62;
for ii = 1:n
    if v(ii) < 3
        cp = 0;
    elseif v(ii) >=3 && v(ii) < 10
        cp = 0.4;
    elseif v(ii) >= 10 && v(ii) < 14
        cp = 0.2;
    elseif v(ii) >= 14 && v(ii) < 25
        cp = 0.1;
    elseif v(ii) >= 25
        cp = 0.001;
    end
    model(ii) = k0*v(ii).^3*cp;
end