MATLAB: Is it possible to take inputs as several sets

iput dialog boxuser interface

prompt = {'Enter the co-ordinates of points eg (x1,y1,z1,x2,y2,z2,.....: '};
title = 'Environmental forces';
answer = inputdlg(prompt,title);
forces = str2num(answer{:});
The above code will read any number inputs given by the user. Since they are co-ordinates what if we want to work in such a way that it reads the value in set of 3 i.e. the first three values entered will be x1, y1, z1 then x2, y2, z2… is it possible?

Best Answer

Since you are assuming that every triplet corresponds to an (x,y,z) coordinate, then just extract all the x-, y- and z-coordinate into separate vectors:
 x = forces(1:3:end);  % x-coordinates are 1,4,7,… 
 y = forces(2:3:end);  % y-coordinates are 2,5,8,…
 z = forces(3:3:end);  % z-coordinates are 3,6,9,…
The code would need some logic to ensure that the lengths of all three vectors are the same (for the case where the user did not enter in a multiple of three values):
 if length(x)~=length(y) || length(x)~=length(z)
  % do some handling for case where vectors are not the same length
 end
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