by An Uncommon Lab

vectors_to_states

Convert a state vector history to a series of states given those states as inputs. If the total number of numeric states is ns and the number of time steps represented is nt, then yv is nt-by-ns. The remaining arguments are example states. The outputs will have the same form as the example states, but will be arrays of these states, each nt long, with appropriate values from yv.

When a state is a column or row vector of numeric types, the output will be an nt-by-x array where x is length(state)

When a state is an n-dimensional matrix (neither column nor vector), the output will have the dimensions of the matrix concatenated on the first unused dimension. That is, if the state is a-by-b, the output will be a-by-b-by-nt.

When a state is a struct, the output will be a struct array of length nt.

Otherwise, the state will be a cell array of length nt, each containing the example type filled in with values from yv.

[y1, y2, ... yn] = vectors_to_states(yv, y1, y2, ... yn);

Inputs

Outputs

Examples

A history of 3 samples of a row vector:

yv = [state_to_vector([1 2]).'; ... % Sample 1
      state_to_vector([7 8]).'; ... % Sample 2
      state_to_vector([13 14]).'];  % Sample 3
y  = zeros(1, 2);                   % Example state
ys = vectors_to_states(yv, y)       % 3-by-2 output

ys =
 1     2
 7     8
13    14

A history of 3 samples of 3 different states: a column vector, a cell array, and a struct:

% Make the example states.
y1  = zeros(1, 3).';
y2  = {1, 2; 3 4};
y3  = struct('a', 0, 'b', 0);

% Make the history.
y1v = [state_to_vector([1 2 3].').'; ...
       state_to_vector([7 8 9].').'; ...
       state_to_vector([13 14 15].').'];
y2v = [state_to_vector({1 2; 7 8}).'; ...
       state_to_vector({3 4; 9 0}).'; ...
       state_to_vector({5 6; 1 2}).'];
y3v = [1 2; 3 4; 5 6];
yv  = [y1v, y2v, y3v];

% Get the state histories.
[y1s, y2s, y3s] = vectors_to_states(yv, y1, y2, y3)

y1s =
     1     2     3
     7     8     9
    13    14    15
y2s = 
    {2x2 cell}
    {2x2 cell}
    {2x2 cell}
y3s = 
3x1 struct array with fields:
    a
    b
    

See Also