Search All of the Math Forum:
Views expressed in these public forums are not endorsed by
Drexel University or The Math Forum.


dpb
Posts:
9,089
Registered:
6/7/07


Re: interpolate
Posted:
Dec 27, 2012 10:55 AM


On 12/26/2012 7:45 PM, maryam wrote: > dpb <none@non.net> wrote in message <kbg5ol$ugl$1@speranza.aioe.org>... >> On 12/26/2012 5:03 PM, maryam wrote: >> > dpb <none@non.net> wrote in message <kbfhar$1lo$1@speranza.aioe.org>... ...
>> >> doc interp1 >> >> >> >> >> X = 0:10; V = sin(X); Xq = 0:.25:10; >> >> >> Vq = interp1(X,V,Xq); ...
>> > thank you very much for your answer but I mean we have a matrix nbym: >> > assume M= [a b c;d e f; g h i] >> > I want to interpolate its rows so that is equal to >> > M=[a a+d a+2d a+3d ... 7d b b+d ... b+7d c... c+7d ; d... d+7d... >> f+7d ; >> > g ... i+7d] >> > Can you explain me how I could do it? >> >> I'm virtually certain you asked this same question some days ago and I >> told you then the same thing... >> >> Use interp1() as the above example w/ an interpolating vector of the >> points at which you want interpolants. Here's why I think I remember >> the question and the response, as I pointed out then, since interp1() >> works on columns you'll need to transpose, interpolate, then transpose >> back. >> >> I can't interpret the above [a a+d a+2d ... ) precisely but assuming d >> here is a different 'd' than that of the value in the original M(2,1) >> and is just a delta then the interpolant would seem to be >> linspace(0,N*d,N+1) where N is the number of intervals (7 above) added >> to a, b, c, ..., etc. >> ...
> thank you so much, I'm Beginner in matlab, > I apologize for my request > Is it possible give me matlab code of my question? > I couldn't use 'for' command or M(:,columns) ... > my matrix is 1000by1200 d=delta=1/16 > its values (arrays) is arbitrary here
That's identical to the example I gave except on an array instead of a vector...and a stilltobedetermined precisely interpolant.
What does the 1/16 delta refer tois it a constant or a fraction of the distance between columns, or what? Your description isn't precise (or at least I can't decipher what it is you want clearly enough to actually write a piece of specific code).
Can you give a very small example of a dataset that you could compute the desired result of by hand? It wouldn't have to be but one row and a few values to illustrate what you're actually trying to do...




