From the documentation, using a table as input:
- Each row of Tbl corresponds to one observation, and each column corresponds to one variable.
So the data must be column-oriented.
Taking a clue from the 'pureQuadratic' function, see if this does what you want —
dodWavelet = randn(1,1503).' + sin(2*pi*(0:1502).'/500); % Create Data (Note Transposition To Column Vector)
t_observed = (0:length(dodWavelet(:,1))-1)/10;
y_observed = dodWavelet(:,1);
hfcn = @(X) [ones(size(X)) X X.^2 X.^3];
B0 = rand;
gprMdl1 = fitrgp(t_observed',y_observed,'Basis',hfcn, 'Beta',B0);
format long
Coefficients = gprMdl1.Beta
format short
[ypred1,ysd1, yint1] = predict(gprMdl1,t_observed');
figure
hp1 = plot(t_observed, y_observed, '.', 'DisplayName','Data');
hold on
hp2 = plot(t_observed, ypred1, '-r', 'DisplayName','Regression');
hp3 = plot(t_observed, yint1, '--r', 'DisplayName','95% Confidence Limits');
hold off
grid
legend([hp1 hp2 hp3(1)], 'Location','best')
It seems to work and produce a reasonable result.
EDIT — (30 May 2024 at 22:03)
Added ‘Coefficients’ assignment to display them.
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