I want to calculate velocity. How do I apply my code to all tables in all cells?
2 vues (au cours des 30 derniers jours)
Afficher commentaires plus anciens
Hi,
I have a data set of distances (see "results_distances" attached) and want to calculate the velocity for each row in each table in each cell.
I have the following code:
results_velocity = cell(size(results_distances));
for i = 1:length(results_distances) % iterate over tables in cell array
if ~isempty(results_distances{i}) % check if table is not empty
table_data = results_distances{i};
v_table = table_data; % initialize output table with the same size as input table
% Calculate velocity for each numeric variable (column) in the table
for var = 1:width(table_data)
% Check if the variable is numeric
if isnumeric(table_data{:, var})
% Calculate velocity for each row
for row = 2:size(table_data, 1)
% Subtract previous value from current value and divide by time_interval
v_table{row, var} = (table_data{row, var} - table_data{row-1, var}) / time_interval;
end
end
end
results_velocity{i} = v_table; % store velocity table in output cell array
end
end
However, when I run my code, it seems to only apply the calculation to the first column of tables in the cell array (see "results_velocity"). What am I doing wrong?
Thanks!
0 commentaires
Réponse acceptée
Voss
le 11 Juin 2024
load('results_distances.mat')
results_distances is of size 3x12
results_distances
so its length is 12. Recall that length() returns the size of the longest dimension.
length(results_distances)
Iterating from 1 to length(results_distances) is iterating over the first 12 elements of results_distances, which in this case is the first 4 columns (since results_distances has 3 rows).
A same-size example using a numeric matrix:
data = reshape(1:36,3,[])
for i = 1:length(data)
data(i)
end
In order to iterate over all elements of results_distances, use numel instead of length.
time_interval = 1;
results_velocity = cell(size(results_distances));
for i = 1:numel(results_distances) % iterate over tables in cell array
if ~isempty(results_distances{i}) % check if table is not empty
table_data = results_distances{i};
v_table = table_data; % initialize output table with the same size as input table
% Calculate velocity for each numeric variable (column) in the table
for var = 1:width(table_data)
% Check if the variable is numeric
if isnumeric(table_data{:, var})
% Calculate velocity for each row
for row = 2:size(table_data, 1)
% Subtract previous value from current value and divide by time_interval
v_table{row, var} = (table_data{row, var} - table_data{row-1, var}) / time_interval;
end
end
end
results_velocity{i} = v_table; % store velocity table in output cell array
end
end
results_velocity
5 commentaires
Plus de réponses (0)
Voir également
Catégories
En savoir plus sur Tables dans Help Center et File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!