How to extract formula from fitrgp.

Hello, I try to find formula from my data it's have multi-input and 1 output ,first I try with 2 input and I got graph 3D to find my Z value (output) but I concern about future, cause it's will have more input, so I want to ask, is my method still work if I have more input ? if not then I need to find formula or anythng else? and how can I find formula?

ps1. although I can find graph 3D but I still can't find Z by interpolat method.

Num_Points = 100;
X_Lin = linspace(min(x),max(x),Num_Points);
Y_Lin = linspace(min(y),max(y),Num_Points);
[X,Y] = meshgrid(X_Lin,Y_Lin);

f = scatteredInterpolant(x, y, z);
Z = f(X,Y);  
surf(X,Y,Z);
xlabel('x'),ylabel('y'),zlabel('z')
hold on;
plot3(x,y, z,'.r','DisplayName','Observations');

%% from this, it's a code that still error.
x_observed = 152054999201.746;
y_observed = 223791838401.46;
w_observed = interp2( X_Lin, Y_Lin, z,x_observed,y_observed);
disp(w_observed);

if you help me to make my code can be useful, I will b very greatful.

ps2. apologize for my bad english and my bad story-telling.

Answer 1

[Gokul Nath S J]

Hi Gullanan,

As per my understanding it seems that you are receiving an error while working with the interp2 command. Since the error message is not attached, I can give some possible suggestion which can be helpful.

Please refer the following example to understand the interp2 behaviour.

[x, y, z] = peaks(10);
interp2(x, y, v, 1, 3)

The variables x, y are unknown to the question. However for correctly debugging the question, one needs the information of x and y. It might be possible that the arguments which were passed to the interp2 is lacking some dimensional issue. The calculation of z should be made sure to observe the correct number of outputs.

For more information regarding the issue, Kindly refer the following link.

https://in.mathworks.com/help/matlab/ref/interp2.html

with regards,

Gokul Nath S J