MATLAB Central Newsreader - 3D Mapping

3D Mapping

Alicia Sanchez — Thu, 01 Jun 2006 16:11:05 -0400

I need to plot a figure more or less like the one showed in the "surf
function". My problem is that I have 3 vectors of size Nx1, that
indicate the x and y coordinates, and the other one the power value
associated to that point (x,y).

My problem is that I need to make some interpolation with the values
that I have, in order to construct the surface to be respresented. In
this picture is shown more or less the values that I've got. The x´s
represents a different value. So i need to cover the holes in between
them, so I can draw a surface where the height (or color) indicates
the value of the power.
Any of you know how to solve this problem?

|
| x x
| x x x x x x
|xx x x x x x x
|xx x x
|x x x x x x x
|_________________________

Re: 3D Mapping

Perry — Thu, 01 Jun 2006 16:29:45 -0400

If you need to fill the gaps in the third array (the power values)
may I suggest 2 loops :

For y = 1:n
%=========================================
% Outer loop control, for n rows
%=========================================
For x = 1:n
%=========================================
% Inner loop control, for n columns. I'm assuming you have as many
columns as rows, and I assume an empty value is simply a [] in the
power vector.
%=========================================

if isempty(power_vector(y,x))
%==========================================
% Perform some interpolation action
% Example as below, but this assumes you no not have empty entries
side by side !!
%===========================================

switch x
case {1,n}
%==================================================
% If beginning of end of row then cannot average between next higher
and lower columns
%==========================================================
    if x == 1
         power_vector(y,x) = power_vector(y,x+1); % As example fill
with next higher value
    else
         power_vector(y,x) = power_vector(y,x-1);
    end

otherwise
%===========================================
% Average next higher and lower power values
%===========================================

power_vector(y,x) =(power_vector(y,x+1)...
+ power_vector(y,x-1))/2

end

end

end

Alicia Sanchez wrote:
>
>
> I need to plot a figure more or less like the one showed in the
> "surf
> function". My problem is that I have 3 vectors of size Nx1, that
> indicate the x and y coordinates, and the other one the power value
> associated to that point (x,y).
>
> My problem is that I need to make some interpolation with the
> values
> that I have, in order to construct the surface to be respresented.
> In
> this picture is shown more or less the values that I've got. The
> x´s
> represents a different value. So i need to cover the holes in
> between
> them, so I can draw a surface where the height (or color) indicates
> the value of the power.
> Any of you know how to solve this problem?
>
> |
> | x x
> | x x x x x x
> |xx x x x x x x
> |xx x x
> |x x x x x x x
> |_________________________

Re: 3D Mapping

CRet — Fri, 02 Jun 2006 00:01:25 -0400

"Perry" <reply@board.thanks> wrote in
news:ef386c5.0@webcrossing.raydaftYaTP...
[skip]
>
> if isempty(power_vector(y,x))
>
[skip]

"Alicia Sanchez" <aliciasmm82@gmail.com> wrote in
news:ef386c5.-1@webcrossing.raydaftYaTP...
> I need to plot a figure more or less like the one showed in the "surf
function".
> My problem is that I have 3 vectors of size Nx1,

Sorry Perry, but your "power_vector" matrice not correspond to the initial
condition indicate by Alicia.

C.Ret

Re: 3D Mapping

CRet — Fri, 02 Jun 2006 00:33:26 -0400

Dear Akicia,

look at the doc griddata and the exemple.

Hope this help you.
C.Ret

"Alicia Sanchez" <aliciasmm82@gmail.com> wrote in
news:ef386c5.-1@webcrossing.raydaftYaTP...
> I need to plot a figure more or less like the one showed in the "surf
> function". My problem is that I have 3 vectors of size Nx1, that
> indicate the x and y coordinates, and the other one the power value
> associated to that point (x,y).
>
> My problem is that I need to make some interpolation with the values
> that I have, in order to construct the surface to be respresented. In
> this picture is shown more or less the values that I've got. The x´s
> represents a different value. So i need to cover the holes in between
> them, so I can draw a surface where the height (or color) indicates
> the value of the power.
> Any of you know how to solve this problem?
>
> |
> | x x
> | x x x x x x
> |xx x x x x x x
> |xx x x
> |x x x x x x x
> |_________________________

Re: 3D Mapping

Perry — Fri, 02 Jun 2006 04:52:04 -0400

CRet,

You're right ! Utter rubbish I wrote. I blame it on me responding
late at night.

Sorry Alicia !

CRet wrote:
>
>
> Dear Akicia,
>
> look at the doc griddata and the exemple.
>
> Hope this help you.
> C.Ret
>
>
> "Alicia Sanchez" <aliciasmm82@gmail.com> wrote in
> news:ef386c5.-1@webcrossing.raydaftYaTP...
>> I need to plot a figure more or less like the one showed in the
> "surf
>> function". My problem is that I have 3 vectors of size Nx1,
that
>> indicate the x and y coordinates, and the other one the power
> value
>> associated to that point (x,y).
>>
>> My problem is that I need to make some interpolation with the
> values
>> that I have, in order to construct the surface to be
> respresented. In
>> this picture is shown more or less the values that I've got.
The
> x´s
>> represents a different value. So i need to cover the holes in
> between
>> them, so I can draw a surface where the height (or color)
> indicates
>> the value of the power.
>> Any of you know how to solve this problem?
>>
>> |
>> | x x
>> | x x x x x x
>> |xx x x x x x x
>> |xx x x
>> |x x x x x x x
>> |_________________________
>
>
>