WTEnv: Environment that exists to store intermediate calculations for re-use within the same R session.

Description

Environment that stores results of long calculations so that they can be made available for immediate reuse.

Arguments

RELEASE

Version 3.9 Copyright Guy Nason 1998

Author

G P Nason

Details

This environment is created on package load by wavethresh. The results of some intermediate calculations get stored in here (notably by PsiJ, PsiJmat and ipndacw). The reason for this is that the calculations are typically lengthy and it saves wavethresh time to search the WTEnv for pre-computed results. For example, ipndacw computes matrices of various orders. Matrices of low order form the upper-left corner of matrices of higher order so higher order matrix calculations can make use of the lower order instances.

A similar functionality was present in wavethresh in versions 4.6.1 and prior to this. In previous versions computations were saved in the users current data directory. However, the user was never notified about this nor permission sought.

The environment WTEnv disappears when the package disappears and the R session stops - and results of all intermediate calculations disappear too. This might not matter if you never use the larger objects (as it will not take much time to recompute).

Examples

Run this code

#
# See what it is
#
WTEnv
#
#
# Compute something that uses the environment
#
fred <- PsiJ(-5)
#
# Now let's see what got put in
#
ls(envir=WTEnv)
#[1] "Psi.5.10.DaubLeAsymm"