epgsum {emuR}

Sum contacts in palatograms.

Description

The function calculates EPG contact profiles, i.e. sums active or inactive electrodes optionally by row and/or column in palatographic data.

Usage

epgsum(
  epgdata,
  profile = c(1, 3),
  inactive = FALSE,
  rows = 1:8,
  columns = 1:8,
  trackname = "EPG-sum"
)

Arguments

epgdata

An eight-columned EPG-compressed trackdata object, or an eight columned matrix of EPG-compressed trackdata, or a 3D palatographic array that is the output of palate()

profile

A numeric vector of one or two values. The options are as follows. c(1,3) and c(1) sum the contacts by row, but the latter outputs the summation in the rows. c(2,3) and c(2) sum the contacts by column, but the latter outputs the summation in the columns. (see also rows and columns arguments and the examples below for further details).

inactive

a single element logical vector. If FALSE (the default), then the active electrodes (i.e, 1s) are summed, otherwise the inactive electrodes (i.e., 0s) are summed.

rows

vector of rows to sum

columns

vector of columns to sum

trackname

single element character vector of the name of the track (defaults to "EPG-sum")

Details

Contact profiles are standard tools in electropalatographic analysis. See e.g., Byrd (1996) for details.

Value

These functions return a trackdata object if they are applied to an eight-columned EPG-compressed trackdata object, otherwise a one-columned matrix.

Author(s)

Jonathan Harrington

References

BYRD, D. (1996). Influences on articulatory timing in consonant sequences. Journal of Phonetics, 24, 209-244.

GIBBON, F. AND NICOLAIDIS, K. (1999). Palatography. In W.J. Hardcastle & N. Hewlett (eds). Coarticulation. (pp. 229-245). Cambridge University Press: Cambridge.

See Also

epgai epgcog epggs palate

Examples

# Trackdata object of the sum of contacts in the 1st segment of polhom.epg
epgsum(polhom.epg[1,])
# as above, but the summation is in rows 1-3 only.
epgsum(polhom.epg[1,], rows=c(1:3))
# as epgsum(polhom.epg[1,]), except sum the inactive electrodes in columns 3-6.
epgsum(polhom.epg[1,], columns=3:6, inactive=TRUE)
# Obtain compressed EPG-trackdata object for the 1st four segments of polhom.epg
# at the temporal midpoint
mid <- dcut(polhom.epg[1:4,], .5, prop=TRUE)
# sum of contacts in these four palatograms.
epgsum(mid)
# gives the same result as the previous command.
p <- palate(mid)
# sum the contacts in the palatograms.
epgsum(p)
# as above, but show the separate row summmations. 
epgsum(p, 1)
# as above, but show the separate column summmations. 
epgsum(p, 2)
# sum of the contacts in rows 1-4 showing the separate row summations.
epgsum(p, 1, rows=1:4)
# sum of the contacts in rows 1-4 showing the separate column summations.
epgsum(p, 2, rows=1:4)
# sum of the contacts in columns 3-6  showing the separate row summations.
epgsum(p, 1, columns=3:6)
# sum of the contacts in columns 3-6  showing the separate column summations.
epgsum(p, 2, columns=3:6)