emu.track {emu}R Documentation

Retrieve Numerical Data

Description

Takes the result of a database query and retrieves corresponding time-series data from the database.

Usage

emu.track(seglist, trackname, cut=NULL, npoints=NULL, template=attr(seglist, "database"))

Arguments

seglist An Emu segment list.
trackname The name of the data track to retrieve, a string. This must be a track name defined in the database template.
cut An optional cut time for segment data, ranges between 0 and 1, a value of 0.5 will extract data only at the segment midpoint.
npoints An optional number of points to retrieve for each segment or event. For segments this requires a cut= argument and data is extracted around the cut time. For events data is extracted around the event time.
template The database to retrieve the data from, this should not normally be set.

Details

emu.track takes a segment list as input and retrieves associated numerical data from the corresponding database. The segment list will usually be the result of a call to emu.query but could be constructed with the make.seglist function. The result is either a two dimensional array of data or an object of class trackdata which may contain multi-column data from many tokens.

Value

If only two arguments are supplied the entire data track is retrieved for each segment in the segment list. The amount of data returned will depend on the sample rate and number of columns in the track requested. The returned data is packaged up as a trackdata object.
The optional cut argument specifies a cut point as a fraction of the duration of each segment in the segment list. If this is specified the data at this single cutpoint will be extracted rather than that for the entire track. The result of emu.track with the cut arguement is a two dimensional array of data with one row per segment in the original segment list and one column per column in the requested track. This array can be treated like any other array in Splus.
If the input segment list is in fact an event list (ie. is derived from an annotation level defined as events in the database template) then the result of emu.track is the same as if the cut argument was specified.
If the npoints argument is specified, it defines the number of points that will be returned for each segment or event. The cut argument is required if the input is a segment list (as opposed to an event list).

Note

This function calls external scripts via tcltk which are part of the Emu speech database system and so requires this system to be installed on your computer. See the Emu web site for details.

Author(s)

Steve Cassidy <Steve.Cassidy@mq.edu.au>

References

See the Emu documentation at: http://www.shlrc.mq.edu.au/emu

See Also

dplot dapply

Examples


## assumes a database called demo is available on your system and that
## the Emu system is installed. 
data(vowlax)

# find all Phonetic vowels in the database
## Not run: segs <- emu.query("demo", "*", "Phonetic=vowel")

# get formant data at the midpoint, returns an array
## Not run: data.mid <- emu.track( segs, "fm", cut=0.5 )

# get formant data for entire tracks, returns trackdata
## Not run: data.all <- emu.track( segs, "fm" )

summary(data.all)


[Package emu version 4.0 Index]