read.spc {zipfR} | R Documentation |
read.spc
loads frequency spectrum from .spc
file
write.spc
saves frequency spectrum object in .spc
file
read.spc(file) write.spc(spc, file)
file |
character string specifying the pathname of a disk file. See section "Format" for a description of the required file format |
spc |
a frequency spectrum, i.e.\ an object of class
spc |
A TAB-delimited text file with column headers but no row names
(suitable for reading with read.delim
). The file must contain
at least the following two columns:
m
Vm
An optional column labelled VVm
can be used to specify
variances of expected class sizes (for a frequency spectrum derived
from a LNRE model or by binomial interpolation).
These columns may appear in any order in the text file. All other columns will be silently ignored.
The .spc
file format does not store the values of N
,
V
and VV
explicitly. Therefore, incomplete frequency
spectra and expected spectra with variances cannot be fully
reconstructed from disk files. Saving such frequency spectra (or
loading a spectrum with variance data) will trigger corresponding
warnings.
read.spc
returns an object of class spc
(see the
spc
manpage for details)
See the spc
manpage for details on spc
objects. See read.tfl
and read.vgc
for
import/export of other data structures.
## Not run: ## examples will not be run during package compilation ## since they would require accessing and writing to ## external files ## load Italian ultra- data ## and write corresponding spectrum to external text file data(ItaUltra.spc) write.spc(ItaUltra.spc,"ultra.spc") ## now ultra.spc is a text file with columns m and Vm ## we ready it back in New.spc <- read.spc("ultra.spc") ## same spectrum as ItaUltra.spc, compare: summary(New.spc) summary(ItaUltra.spc) ## DON'T do the following, incomplete spectrum will not be ## restored properly!!! zm <- lnre("zm",ItaUltra.spc) # estimate model zm.spc <- lnre.spc(zm,N(zm)) # incomplete spectrum from model write.spc(zm.spc,"var.spc") # warnings bad.spc <- read.spc("/Users/baroni/Desktop/var.spc") ## latter is DIFFERENT from zm.spc!!! ## End(Not run)