Discussion :

[oliv27400]

bonjour , je souhaiterai réserver de la place pour une matrice .
LE problème est que au début de mon programme , je ne connais pas le nombre de ligne exacte dont j'aurai besoin , mais seulement l'ordre de grandeur.

Comment puis je faire pour cela. Si vous avez une solution
merci.

[tug83]

Voici ce qu'on peut lire dans:
How do I pre-allocate memory when using MATLAB?

It should be noted that preallocating memory does not make sense if you do not know the eventual size of the matrix you wish to create. This is because one of two cases are likely to occur. Either the preallocated memory will either be too large, resulting in wasted memory; or the allotted memory will be too small for the matrix you are trying to create, resulting in the need to allocate more memory and copy matrix elements to the new space. The latter case will cause you to be just as vulnerable to the memory fragmentation problems you are trying to avoid by preallocating memory.