Evaluate multi-resolution thin-plate spline basis functions at given locations.
This function provides a generic prediction method for mrts objects,
in a similar way as predict.ns and predict.bs in splines package.
# S3 method for mrts
predict(object, newx, ...)object produced from calling mrts.
an n by d matrix of coordinates corresponding to n locations.
not used but needed for the S3 generic/method compatibility.
an n by k matrix of the k basis function in object taken values at newx.