from curve fit to look up table

how you you use the answer to a x,y,z curve fit in a look up table?

Answer 1

[Star Strider]

The question is a bit ambiguous.

Interpolation of some sort would appear to be the best option, and of course the approach depends on whatever the desired result may be.

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[stephen collier]

when i run the fit i get a 1*1sfit as a ans.

hot do i use the ans in a look up table for any value of x and y ?

[Star Strider]

I don’t get anything.

Assuming the arguments are vectors —

x = randn(20,1);
y = randn(20,1);
z = randn(20,1)+2;

xv = linspace(min(x), max(x), numel(x));
yv = linspace(min(y), max(y), numel(y));
[X,Y] = ndgrid(xv,yv);
FSI = scatteredInterpolant(x, y, z);

figure
surf(X, Y, FSI(X,Y), 'FaceAlpha',0.5)
hold on
surf(X, Y, zeros(size(X)), 'EdgeColor','k', 'FaceColor','none')
xq = randn;
yq = randn;
zq = FSI(xq,yq);
coordinates = [xq, yq, FSI(xq,yq)]

coordinates = 1×3

-1.3150 1.1294 1.3476

stem3(xq, yq, FSI(xq,yq), '^r', 'filled', 'MarkerSize',10, 'LineWidth',2)
hold off
grid on
xlabel('X')
ylabel('Y')

This is how I would do it,

.