How do I apply distance formula for 3D coordinate points for all elements in a cell array?

Hi,

I have a cell array where each cell contains a matrix of 3D coordinates (xyz) for three positions (9 columns in total). These are:

head = columns 1-3

left hand = columns 4-6

right hand = columns 7-9

I would like to find the distances between the positions 'head' and 'left hand' for each cell for each element in the columns. I have the following code:

distances_head_lefthand = sqrt(((participant_positions{1,1}(:,4)-participant_positions{1,1}(:,1)).^2)+((participant_positions{1,1}(:,5)-participant_positions{1,1}(:,2)).^2)+((participant_positions{1,1}(:,6)-participant_positions{1,1}(:,3)).^2));

This code works for one cell in a cell array.

How do I need to write this code if I want to apply it to every cell in the cell array and save the output in a new cell array called 'distances_head_lefthand'?

Thank you!

Answer 1

[DGM]

How about something like this?

S = load('participants_head_lefthand_righthand_positions.mat');
head_lh_rh_pos = S.participant_head_lefthand_righthand_positions; % good grief

f = @(x) sqrt(((x(:,4)-x(:,1)).^2) ...
            + ((x(:,5)-x(:,2)).^2) ...
            + ((x(:,6)-x(:,3)).^2));

distances_head_lefthand = cellfun(f,head_lh_rh_pos,'uniform',false)

distances_head_lefthand = 1×3 cell array
    {20×1 double}    {20×1 double}    {20×1 double}

[lil brain]

This works well thanks!