How to quickly save a matrix by adding rows?

1 visualización (últimos 30 días)
Benson Gou
Benson Gou el 22 de Jun. de 2021
Comentada: Stephen23 el 22 de Jun. de 2021
Dear All,
I calculate a row Ai and save it in my defined matrix A using the following way:
A = [A; Ai];
But I foud it took a lot of time. Is there a faster way?
Thanks a lot.
Benson

Respuesta aceptada

dpb
dpb el 22 de Jun. de 2021
Yes. Preallocate the array and index into it...without context it's conjecture what you have/are doing, but the general idea is
A=zeros(max(variable_i),size(A,2)); % preallocate A as array of zeros
for i=1:max(variable_i) % for the loop size each i
% whatever to compute Ai
...
A(i,:) = Ai; % store the new row in A
end
The above will not show degradation in speed as i increases.

Más respuestas (0)

Categorías

Más información sobre String Parsing en Help Center y File Exchange.

Etiquetas

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by