add files for public distribution
based on internal repository 0a462b6 2017-11-22 14:41:39 +0100
This commit is contained in:
77
pmsco/loess/predict.m
Normal file
77
pmsco/loess/predict.m
Normal file
@ -0,0 +1,77 @@
|
||||
NAME
|
||||
predict, pointwise, pred_free_mem, pw_free_mem
|
||||
|
||||
SYNOPSIS
|
||||
#include "loess.h"
|
||||
|
||||
double *eval, coverage;
|
||||
long m, se;
|
||||
struct loess_struct *lo;
|
||||
struct predict_struct *pre;
|
||||
struct ci_struct *ci;
|
||||
|
||||
void predict(eval, m, lo, pre, se)
|
||||
|
||||
void pointwise(pre, m, coverage, ci)
|
||||
|
||||
void pred_free_mem(pre)
|
||||
|
||||
void pw_free_mem(ci)
|
||||
|
||||
PARAMETERS
|
||||
|
||||
eval a vector of length m * p specifying the values of the
|
||||
predictors at which the evaluation is to be carried out.
|
||||
The j-th coordinate of the i-th point is in eval[i+m*j],
|
||||
where 0<=j<p, 0<=i<m.
|
||||
|
||||
m number of evaluations.
|
||||
|
||||
lo k-d tree and coefficients.
|
||||
|
||||
pre predicted values; output by predict(), input to pointwise().
|
||||
|
||||
se logical flag for computing standard errors at eval.
|
||||
|
||||
ci pointwise confidence limits.
|
||||
|
||||
coverage (input) confidence level of the limits as a fraction.
|
||||
|
||||
DESCRIPTION
|
||||
|
||||
predict() takes all the loess structures from earlier calls to
|
||||
loess_setup() and loess(), does an evaluation based on
|
||||
eval and m, and stores the results in the pre structure.
|
||||
if se is TRUE, then pre.se_fit are computed along with the
|
||||
surface values, pre.fit. These returned vectors
|
||||
are vectors of the same structural arrangement as that of eval.
|
||||
|
||||
pointwise() computes the pointwise confidence limits from the
|
||||
result of predict().
|
||||
|
||||
pred_free_mem() and pw_free_mem() frees up the allocated memory
|
||||
used by the pre and ci structures respectively.
|
||||
|
||||
loess_struct, pred_struct, and ci_struct are defined in loess.h
|
||||
and documented in struct.m.
|
||||
|
||||
NOTES
|
||||
|
||||
The computations of predict() that produce the component se_fit
|
||||
are much more costly than those that producing the fit,
|
||||
so the number of points at which standard errors are
|
||||
computed should be modest compared to those at which we do
|
||||
evaluations. Often this means calling predict() twice,
|
||||
once at a large number of points, with se = FALSE,
|
||||
to get a thorough description of the surface; and once
|
||||
at a small number of points, with se = TRUE,
|
||||
to get standard-error information.
|
||||
|
||||
Suppose the computation method for loess surfaces is
|
||||
interpolate, the default for the argument surface. Then the
|
||||
evaluation values of a numeric predictor must lie within
|
||||
the range of the values of the predictor used in the fit.
|
||||
|
||||
SEE ALSO
|
||||
|
||||
loess_setup, loess, loess_summary, loess_free_mem
|
Reference in New Issue
Block a user