MATLAB: What does “IND” do

functionindind functionMATLABmatlab functionoctave

Could someone please explain what is the meaning behind the following sequences? I don't quite understand the meaning of the "ind" function.
Thank you!
P.S. I don't know whether it is worth mentioning, but the code was written using Octave.
————————-
indBl=[];
%


if (Blt(1) == 1)
    indBl=[indBl 1];  
end
if (Blr(1) == 1)
    indBl=[indBl 2];  
end
%
if (Blt(2) == 1)
   indBl=[indBl 2*NE1+1];  
end
if (Blr(2) == 1)
   indBl=[indBl 2*NE1+2];  
end
%
if (Blt(3) == 1)
   indBl=[indBl 2*NE+1];   
end
if (Blr(3) == 1)
   indBl=[indBl 2*NE+2];   
end

Best Answer

There is no "ind" function in that code.
What the code is doing is adding values to the end of a list.
If Blt(1) is 1, then add 1 to the end of the list.
Then if Blr(1) is 1, add 2 to the end of the list (that might have been updated in the previous step.)
Then if Blt(2) is 1, add 2*NE1+1 to the end of the list.
And so on.
The [] is the same as horzcat() for this purpose, so you could write it as
if Blt(1) == 1
    indBl = horzcat(indBl, 1);
end
You could also write it as
if Blt(1) == 1
    indBl(end+1) = 1;
end
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