What is wrong with: [betta;del​ta;gamma]=​inv([ab ab_cd -cd])*[C-A];

Hi

[betta;delta;gamma]=inv([ab ab_cd -cd])*[C-A];

betta, delta and gamma should be scalars.

ab, ab_cd, cd, C and A are column vectors with 3 rows (e.g. [1;2;3]).

I want that

betta = leftvektor(1)

delta = leftvektor(2)

gamma = leftvektor(3)

Matlab shows an error but I am not sure why. Does anyone knows why?

Answer 1

[Bruno Luong]

You cannot capture elements of array on the lhs directly to variables, you have to split it:

x = inv([ab ab_cd -cd])*[C-A];
betta = x(1); % beta is better me think
delta = x(2);
gamma = x(3);

Answer 2

[John D'Errico]

Why? This is because what you want to do is not valid in MATLAB. You can want for anything. If wishes were horses, beggars would ride.

You cannot split a result as a vector into multiple arguments.

Can you solve the problem? Well, yes. Sigh. Write a little helper function that will take a vector, and automatically split it into scalars.

function varargout = split2scalars(Vec)
  % splits a vector of length n into n scalars
  n = numel(Vec);
  varargout = mat2cell(Vec(:),ones(n,1),1);

So ...

[Vx,Vy,Vz] = split2scalars(1:3)
Vx =
     1
Vy =
     2
Vz =
     3

Use it as:

[betta;delta;gamma] = split2scalars(inv([ab ab_cd -cd])*[C-A]);