question about how to avoid using eval

Hello, all.

I got to know that using "eval" is not efficient and may cause several problems. I have used "eval" a lot in my previous codes.

If I want to replace the following expression without using "eval", would anyone help me one this? Thank you very much.

 for jjjj=1:5
     for iiii=1:40
        for kkkk=1:3
             x1(kkkk,:) = (1:10)*kkkk;
             eval(['Resp.Phi',num2str(jjjj),'.Mu',num2str(iiii),'.Respx1(kkkk,:) = x1(kkkk,:);']);
  end
     end
 end

Answer 1

[Walter Roberson]

             Resp.(sprintf('Phi%d',jjjj).(sprintf('Mu%d',iiii)),.Respx1(kkkk,:) = x1(kkkk,:);

[Baozai]

Thank you, Walter.

But it seems it doesn't work properly. I got the following error in Matlab (matlab 2014b)

Undefined variable "sprintf" or class "sprintf".

[Walter Roberson]

   Resp.(sprintf('Phi%d',jjjj)).(sprintf('Mu%d',iiii)),.Respx1(kkkk,:) = x1(kkkk,:);

[KSSV]

I think comma before .Respx1 is not needed. It throws error.

[Walter Roberson]

You are right,

   Resp.(sprintf('Phi%d',jjjj)).(sprintf('Mu%d',iiii)).Respx1(kkkk,:) = x1(kkkk,:);

[Baozai]

This works, thank you very much.

Answer 2

[KSSV]

iwant = cell(5,40,3) ;
for jjjj=1:5
    for iiii=1:40
        for kkkk=1:3
            x1(kkkk,:) = (1:10)*kkkk;
            iwant{jjjj,iiii,kkkk}= ['Resp.Phi',num2str(jjjj),'.Mu',num2str(iiii),'.Respx1(kkkk,:) = x1(kkkk,:);'] ;
        end
    end
end

[Baozai]

Hi, KSSV:

Thank you very much for replying. But I am afraid this is not what I want.

Resp is actually a structure that contains different vectors. The Structure is like:

Resp.Phi1.Mu1.Respx1 = [1 2 3 4 5 6 7 8 9 10; 2 4 6 8 10 12 14 16 18 20; 3 6 9 12 15 18 21 24 27 30]

Resp.Phi1.Mu2.Respx1 = [1 2 3 4 5 6 7 8 9 10; 2 4 6 8 10 12 14 16 18 20; 3 6 9 12 15 18 21 24 27 30]

Resp.Phi1.Mu3.Respx1 = [1 2 3 4 5 6 7 8 9 10; 2 4 6 8 10 12 14 16 18 20; 3 6 9 12 15 18 21 24 27 30]

..........

Resp.Phi5.Mu40.Respx1 = [1 2 3 4 5 6 7 8 9 10; 2 4 6 8 10 12 14 16 18 20; 3 6 9 12 15 18 21 24 27 30]

And the values in these matrices are different since the statements inside the loop are more complicated than listed here.

[KSSV]

Resp = struct ;
for jjjj=1:5
    for iiii=1:40
        for kkkk=1:3
            x1(kkkk,:) = (1:10)*kkkk;
            % iwant{jjjj,iiii,kkkk}= ['Resp.Phi',num2str(jjjj),'.Mu',num2str(iiii),'.Respx1(kkkk,:) = x1(kkkk,:);'] ;
        end
        for llll = 1:3
            Resp(jjjj).Phi1(iiii).Mu1(llll).Respx1  = x1 ;
        end
    end
end
Resp(1).Phi1(1).Mu1

[Baozai]

This one also works, thank you very much for your help.