4. Kernel operations

Beside addition, multiplication and power, the function where() can be used to make a kernel that switches between two kernels based on a local condition.

lsqfitgp.where(condfun, kernel1, kernel2, dim=None)

Make a kernel(x, y) that yields:

• kernel1(x, y) where condfun(x) and condfun(y) are True

• kernel2(x, y) where condfun(x) and condfun(y) are False

• zero where condfun(x) is different from condfun(y)

Parameters:

condfuncallable

Function that is applied on an array of points and must return a boolean array with the same shape.

kernel1Kernel

Kernel used where condfun yields True.

kernel2Kernel

Kernel used where condfun yields False.

dimstr or None

If specified, when the input arrays are structured, condfun is applied only to the field dim. If the field has a shape, the array passed to condfun still has dim as explicit field.

Returns:

Kernel

If both kernel1 and kernel2 are IsotropicKernel, the class is IsotropicKernel.