Questions about the elapsed time of Enumeration

Hi,Everyone:

Today I want to show all possible result of 4 variables ,all of theirs range are from 1:0.1:10, 1 1 1 1 → 1 1 1 1.1 → 1 1 1 1.2 ... to 10 10 10 10.

I run my code,it has runs more than 17 hours,is it a acceptable phenomenon?

My code is following:

 tic;

 final=10;
 Range=[1:0.1:final];
 Total = length(Range)^4

 weight=zeros(1,4);
 cont=0;
for weight1=Range
    for weight2=Range
        for weight3=Range
            for weight4=Range

                if  abs(weight1-0) > 1e-8
                    cont=cont+1;
                    weight(cont,:)=[weight1 weight2 weight3 weight4];

                end
            end
        end
    end
 toc;

If my code should be adjusted, improved, please tell me your opinions,let's discuss.

Thanks for first !!

Answer 1

[Paridhi Yadav]

Hey in your code you are adding a row in weight every time the loop runs, instead of this while initializing weight give total number of rows like this weight = zeros(Total,4).

tic;
final=10;
Range=[1:0.1:final];
Total = length(Range)^4
weight=zeros(Total,4);
cont=0;
for weight1=Range
    for weight2=Range
        for weight3=Range
            for weight4=Range
                if  abs(weight1-0) > 1e-8
                    cont=cont+1;
                    weight(cont,:)=[weight1 weight2 weight3 weight4];
                end
            end
        end
    end
end
toc;

[Zoe Lin]

Dear Paridhi Yadav:

It still work,finally, weight matrix will be (Total,4), too.