Re: [Maxima-discuss] How to make a 3d surface plot from 2d data matrix?

[Jaime V. <vi...@fe...>]

Hello,

On 12/10/24 15:50, 德馬堤 wrote:
>
> Hello,
>
>
> let matrix M have some data:
>
> M:matrix([1,2,2],[4,5,3],[7,8,4],[10,11,5])$
>
>
> In the simplest case the data can be plotted as a 3d colored surface 
> assuming that the row number equals x, the column number equals to y, 
> and the data M[x,y] equals to z.
>
>
> How can this be done in general (the matrix could be 1000x1000)?
>
Perhaps the example given in the manual can help you?


M:matrix([1,2,2],[4,5,3],[7,8,4],[10,11,5])$

f(x, y) := float('M [round(x), round(y)])$

plot3d (f(x,y), [x,1,3], [y,1,3], [grid,2,2], nolegend)$


>
> A more advanced case is if the row number refers to a specific x 
> value, and the column number to a specific y value, both given a 
> lists. E.g. for the above simple matrix:
>
> X:[1,5,10,20]$
>
> Y:[1,5,10]$
>
>
Sorry. I don't understand how you got those numbers from the M matrix 
(where did 20 come from?) and what kind of plot you are expecting to get 
with 4 values of x and only 3 values of y.


Regards,

Jaime