Kernel covariance
The kernel sets prior covariance between function values at two inputs.
Predicting curves together with uncertainty
A Gaussian process places a probability distribution over functions. Conditioning on observed data produces both a posterior mean curve and location-dependent uncertainty.
The essential idea: the kernel expresses which inputs should have similar function values.
The kernel sets prior covariance between function values at two inputs.
Observation noise adds variance to the covariance matrix diagonal.
Adjust length scale and observation noise. The mean and uncertainty band respond together.
GPR uses covariance structure to combine nearby observations into predictions with explicit uncertainty.