how can i use linspace to generate a row vector with two similar points?

7 vues (au cours des 30 derniers jours)
davood
davood le 28 Juil 2013
i am creating an initial guess vector. As i have a multipoint BVPs, i should use double entries in the vector for the interface point. i used linspace(2,20,1000). but i want it to have two 16. how can i do it?
thank you
  2 commentaires
dpb
dpb le 28 Juil 2013
What's a BVP?
Please clarify what you really want...give a small example possibly explaining how you arrived at the result.
davood
davood le 28 Juil 2013
BVP stands for boundary value problem. i am using this page: http://www.mathworks.com/help/matlab/math/boundary-value-problems.html
my question is about the part witch is written:
5.Create an initial guess. For multipoint BVPs, when creating an initial guess using bvpinit, use double entries in xinit for the interface point xc.
thank you

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dpb
dpb le 28 Juil 2013
Modifié(e) : dpb le 28 Juil 2013
bp=16; % breakpoint value
sp= 2; % startpoint
ep=20; % endpoint
a0=[linspace(sp,bp,N1) linspace(bp,ep,N2)];
N1, N2 could be Ntot/2 or ratio by the distance between breakpoint and overall range to keep uniform or however is best for the particular problem.
If more breakpoints expand on the above.
  2 commentaires
davood
davood le 28 Juil 2013
thank you so much
dpb
dpb le 28 Juil 2013
W/ time, you'll dream up a zillion other ways to code the above "plain vanilla" approach.... :)
The point of the earlier question was that there's little hope of providing a really responsive answer (as Azzi's shows) w/o the groundrules laid out clearly.

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Plus de réponses (1)

Azzi Abdelmalek
Azzi Abdelmalek le 28 Juil 2013
a=sort([16 linspace(2,20,1000)])
  1 commentaire
davood
davood le 28 Juil 2013
Modifié(e) : davood le 28 Juil 2013
thank you. but if it was linspace(2,21,1000), which does not contain 16, then what could i do to have two 16?
my regards

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