Filter out negative values

I have the following iterations running But how can I filter out the negative answer and the allow the program just to run on positive values

    a=20000:5000:90000
    for ct1=1:1:length(a)
        b=300:20:460
        for ct2=1:1:length(b)
            c=150:10:300
            for ct3=1:1:length(c)
                d=0.5:0.1:0.8
                for ct4=1:1:length(d)
                    e=2000:1000:2300
                    for ct5=1:1:length(e)
                        x(ct1,ct2,ct3,ct4,ct5)=a(ct1)+ b(ct2)- (c(ct3))^2 + d(ct4)+ e(ct5)
                    end
                end
            end
        end
    end

Answer 1

[Matt J]

After x is generated,

    x(x<0)=something;

[Arjun]

ok let say the next function is y = x +32; but I wan only the positive value of x to go in the calculation.....each time the iteration above gives negative value of x it won't be used in order to calculate y.

[Matt J]

After the loops are done,

 y(x>=0)=x(x>=0)+32;

[Arjun]

thanx alot fren....=)

Answer 2

[Mahdi]

You can try using the subplus function.

For example, you would use

x(ct1,ct2,ct3,ct4,ct5)=subplus(a(ct1)+ b(ct2)- (c(ct3))^2 + d(ct4)+ e(ct5))

[Arjun]

ok let say the next function is y = x +32; but I wan only the positive value of x to go in the calculation.....each time the iteration above gives negative value of x it won't be used in order to calculate y.

[Sean de Wolski]

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