How to generate names?

I want to make my code shorter.

I have this code:

Sheetname1=txt1{1,3};
Sheetname2=txt2{1,3};
Sheetname3=txt3{1,3};
Sheetname4=txt4{1,3};
Sheetname5=txt5{1,3};
Sheetname6=txt6{1,3};

instead there should be a for loop

for i=1:6
 Sheetname'write i'=txt'write i'{1,3};
end

how to :) ?

[Hassan F]

Is there a specific reason why you implemented your script this way? Such a for loop will be slow and hard to read later on.

Answer 1

[Walter Roberson]

http://matlab.wikia.com/wiki/FAQ#How_can_I_create_variables_A1.2C_A2.2C....2CA10_in_a_loop.3F

[Jan]

+1. Same contents as in the Wiki, but stored locally: Answers: How to create variables in a loop

Answer 2

[Hassan F]

You can use eval

for i=1:6
 eval(['Sheetname' num2str(i) '=txt' num2str(i) '{1,3};'])
end

[Walter Roberson]

... but it is not advised.

[Hassan F]

Well yes, this is slow and hard to read. But for creating just a handful of variables it shouldn't matter.

[Matt J]

No, it's still not advised because

• You're introducing variables non-explicitly into the workspace (so-called poofing). This creates hazards discussed here.
• Enumerating variables through their names makes them hard to index later

The better thing to do here would be

    for i=1:6
     Sheetname{i} = eval(['txt' num2str(i) '{1,3};'])
    end

[Jan]

I do think that it matters. Programmers get used to use methods they are used to use. The more EVAL you write, the more acceptable does this command look, because we are human.

Much better in theory, practice and from the viewpoint of training the brain to think in efficient ways:

Sheetname{1} = txt{1,3};
Sheetname{2} = txt{2,3};
Sheetname{3} = txt{3,3};
Sheetname{4} = txt{4,3};
Sheetname{5} = txt{5,3};
Sheetname{6} = txt{6,3};

Never include an index in the name of a variable. You would not include your current weight to your name also, because the inconveniences are obviously.

Kind regards, Jan70.6kg

[Hassan F]

Totally makes sense.

Hassan74.0kg

Answer 3

[Hello kity]

I tried this : >>

for i=1:6
A=['Sheetname' sprintf('%d' , i)];
B=['txt' sprintf('%d', i)];
A(i)=B{1,3}(i);
 end
??? Cell contents reference from a non-cell array object.

somehow it gives error about B{1,3}

while

>> txt1{1,3}

ans =

T1

[Hassan F]

See my answer http://www.mathworks.se/matlabcentral/answers/58253#answer_70475, but you should avoid this solution and use cells or other classes which suits your data the most.

Answer 4

[Azzi Abdelmalek]

A=cell(1,6);
for ii=1:6
A{ii}=sprintf('Sheetname%d' , ii)
end

Answer 5

[Image Analyst]

My m-files are usually 2-3 thousand lines long. I never worry about saving a paltry 3 lines. Why do you care? If you want to use fewer variables, say use a cell array for Sheetname instead of 6 variables, then you could do that, but with only 6 variable, it's really no big deal. Now if you had dozens or hundred variables named like that (which we see sometimes).....then yes, you'd want an array, but I'm not going to ding you for only 6 uniquely named variables.