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convert.wst


Convert a wst object into a non-decimated wd object.

DESCRIPTION

Convert a packet-ordered non-decimated wavelet transform object into time-ordered non-decimated wavelet transform object.

USAGE

convert.wst(wst)

REQUIRED ARGUMENTS

wst
The wst class object that you wish to convert.

OPTIONAL ARGUMENTS

None.

VALUE

An time-ordered wd object containing exactly the same information as the input object but ordered differently as a time-ordered object.

DETAILS

In WaveThresh3 a non-decimated wavelet transform can be ordered in two different ways: as a time-ordered or packet-ordered representation. The coefficients in the two objects are exactly the same it is just their internal representation and ordering which is different. The two different representations are useful in different situations. The packet-ordering is useful for curve estimation applications and the time-ordering is useful for time series applications.

See Nason, Sapatinas and Sawczenko, 1998 for further details on ordering and weaving.

Note that the output object will be of the non-decimated type. In other words the type component of the output object will be "station".

Once the input object has been converted the output can be used with any of the functions suitable for the wd object with type component equal to "station".

The actual weaving permutation for shuffling coefficients from one representation to another is achieved by the getarrvec function.

RELEASE

Version 3.6 Copyright Guy Nason 1997

SEE ALSO

convert, convwd.htm, getarrvec, wd, wd object, wst, wst object.

EXAMPLES

#
# Generate a sequence of 32 random normals (say) and take their
# packet-ordered non-decimated wavelet transform
#
myrand <- wst(rnorm(32))
#
# Print out the result (to verify the class and type of the object)
#
myrand
#Class 'wst' : Stationary Wavelet Transform Object:
#       ~~~  : List with 5 components with names
#              wp Carray nlevels filter date 
#
#$wp and $Carray are the coefficient matrices
#
#Created on : Tue Sep 29 12:29:45 1998 
#
#summary(.):
#----------
#Levels:  5 
#Length of original:  32 
#Filter was:  Daub cmpct on least asymm N=10 
#Date:  Tue Sep 29 12:29:45 1998 
#
# Yep, the myrand object is of class: wst object.
#
# Now let's convert it to class wd. The object
# gets returned and, as usual in S, is printed.
#
convert(myrand)
#Class 'wd' : Discrete Wavelet Transform Object:
#       ~~  : List with 8 components with names
#              C D nlevels fl.dbase filter type bc date 
#
#$ C and $ D are LONG coefficient vectors !
#
#Created on : Tue Sep 29 12:29:45 1998 
#Type of decomposition:  station 
#
#summary(.):
#----------
#Levels:  5 
#Length of original:  32 
#Filter was:  Daub cmpct on least asymm N=10 
#Boundary handling:  periodic 
#Transform type:  station 
#Date:  Tue Sep 29 12:29:45 1998 
#
# The returned object is of class wd with a
# type of "station".
# I.e. it has been converted successfully.