Question

I’m trying to do a script for nodal analysis for an arbitrary circuit(much like spice).I want to import data from a text file and create a matrice on which further operations will be based on.
so I’ve used textscan

fid = fopen('text2.txt');
netlist = textscan(fid,'%s%s%d%d%d%d%f');

so for an input file like this:

R1 R 1 0 3 0 0 
C1 C 1 0 5 0 0 
L1 L 2 1 10 0 0 
R2 R 1 2 1 0 0 
i1 Iac 2 0 1 1 0.523

the result wil be this

 {5x1 cell}    {5x1 cell}    [5x1 int32]    [5x1 int32]    [5x1 int32]    [5x1 int32]
 [5x1 double]

the problem is, now I can’t call any individual value from the matrice. So I’m trying to figure out how to recreate the original matrice(if possible) and if that didn’t work, could you show me a way to call individual elements (like for example C in (2,2)?
Thanks in advance

Answer 1

Cell arrays are simply another way to store data. Specifically, cell arrays are needed when each cell contains data of different type or different dimensions (in which case, using a matrix won’t work).

To access an individual element in the cell array, you use curly braces ({}). After textscan your data is stored as columns, so you first access the i-th column by C{i}.

Then you need to think what your cell contains. Column 2 contains strings, so it’s another cell array (you can also verify it in the result — column 2 is described as a {5x1 cell}). Therefore, you’ll need to use curly braces again. If you want to access the 2nd element in the 2nd column, you will have to write:

C{2}{2}

P.S.
If you were to access the 2nd element in the 3rd column, you’d be using round braces () for the second subscript, because the second column is a vector. In such case, the syntax should be:

C{3}(2)