acepack (version 1.6.1)

set_control: Set internal parameters that control ACE and AVAS algorithms

Description

These parameters are used in the smoothing routines of ACE and AVAS. ACE and AVAS both have their own smoothing implementations. This sets them globally for the package.

The default values are good for the vast majority of cases. This routine is included to provide complete control to the user, but is rarely needed.

Usage

set_control(
  alpha = NULL,
  big = NULL,
  span = NULL,
  sml = NULL,
  eps = NULL,
  spans = NULL,
  maxit = NULL,
  nterm = NULL
)

Arguments

alpha

numeric(1); AVAS; Controls high frequency (small span) penalty used with automatic span selection (base tone control). An alpha < 0.0 or alpha > 10.0 results in no effect. Default is 5.0.

big

numeric(1); ACE and AVAS; a large floating point number. Default is 1.0e30.

span

numeric(1); ACE and AVAS; Span to use in smoothing represents the fraction of observations in smoothing window. Automatic span selection is performed if set to 0.0. Default is 0.0 (automatic).

For small samples (n < 40) or if there are substantial serial correlations between observations close in x - value, then a specified fixed span smoother (span > 0) should be used. Reasonable span values are 0.3 to 0.5.

sml

numeric(1); AVAS; A small number. Should be set so that `(sml)**(10.0)` does not cause floating point underflow. Default is 1e-30.

eps

numeric(1); AVAS; Used to numerically stabilize slope calculations for running linear fits.

spans

numeric(3); AVAS; span values for the three running linear smoothers.

"spans(1)"

Tweeter span. Default is 0.05.

"spans(2)"

Midrange span. Default is 0.2.

"spans(3)"

Woofer span. Default is 0.5.

Warning: These span values should be changed only with great care.

maxit

integer(1); ACE and AVAS; Maximum number of iterations. Default is 20.

nterm

integer(1); ACE and AVAS; Number of consecutive iterations for which rsq must change less than delcor for convergence. Default is 3.

Examples

set_control(maxit=40)
set_control(maxit=20)
set_control(alpha=5.0)
set_control(big=1e30, sml=1e-30)
set_control(eps=1e-3)
set_control(span=0.0, spans=c(0.05, 0.2, 0.5))
set_control(maxit=20, nterm=3)