How fit surface to 2D-array

[Roger Öhlund]

Hi !

I have a small problem and wondered if anyone had a smart solution.
I need to fit a surface to a 2D-array in order to find the maximum value
of the surface.
Using the max / min - finding VI for arrays will only produce the index
of the maximum value,
since I´m trying to find sort of a sub-index value for the maximum this
will not do.
Another problem would likely be to derivate this surface in order to
find it´s maximum.
Anyone done this before?

-- / sincerely

Roger Ohlund, Engineering Physics F95
Lovsele 83, 930 10 Lovanger
Sweden
Tel. +46 0913 410 41, +46 070 33 33 543
mailto:angler@acc.umu.se
mailto:roger.ohlund@boliden.se
http://www.acc.umu.se/~angler/

[Manfred Leffler]

Hello Roger,

2D-array can't be a surface - a surface must be a 3D-array.
If you need the max of a simple splined-2D-array sent me
a personal E-mail.
Or state your problem more detailed.

MfG
Manfred

Roger Öhlund wrote:
> I need to fit a surface to a 2D-array in order
> to find the maximum value of the surface. ...

[Pierre Meyer]

Manfred Leffler wrote:
>
> Hello Roger,
>
> 2D-array can't be a surface - a surface must be a 3D-array.
> If you need the max of a simple splined-2D-array sent me
> a personal E-mail.
> Or state your problem more detailed.
>
> MfG
> Manfred
>
> Roger Öhlund wrote:
> > I need to fit a surface to a 2D-array in order
> > to find the maximum value of the surface. ...

Hello Manfred,
I am sorry, but it IS, nevertheless! Please consider :
A 2-D array is a two dimensional arrangement of numbers. Each number
(element) is associated to an index pair : Xi, Yi.
The value of the element can be interpreted as the Z coordinate of a surface.
The Zi(Xi,Yi) can be seen as sample points of a surface.
What Roger needs, is a vi representing this 3-D surface as a projection

on 2-D (compare to 'surface plot' in NIH-IMAGE which is doing exactly
that taking an image as 2-D array). This is a simple geometrical
problem. I suspect strongly that somebody has already made such a vi.
--
Pierre Meyer                        
Laboratoire de Physique des Solides     
Bt. 510, Universite de Paris Sud         
F 91405 ORSAY, FRANCE               
T : (33)-(0)1 69 15 60 62
Fx : (33)-(0)1 69 15 60 86
e-mail : meyer@lps.u-psud.fr
homepage : http://www.lps.u-psud.fr/