| writeMat {R.matlab} | R Documentation |
This function takes the given variables (...) and places them in a
MAT file structure, which is then written to a binary connection.
Currently only the MAT version 5 file format is supported.
## Default S3 method: writeMat(con, ..., matVersion="5", onWrite=NULL, verbose=FALSE)
con |
Binary connection to which the MAT file structure should be
written to. A string is interpreted as filename, which then will be
opened (and closed afterwards). |
... |
Named variables to be written. |
matVersion |
A character string specifying what MAT file format
version to be written to the connection. If "5", a MAT v5 file
structure is written. No other formats are currently supported. |
onWrite |
Function to be called just before starting to write to connection. Since the MAT file structure does not contain information about the total size of the structure this argument makes it possible to first write the structure size (in bytes) to the connection. |
verbose |
Either a logical, a numeric, or a Verbose
object specifying how much verbose/debug information is written to
standard output. If a Verbose object, how detailed the information is
is specified by the threshold level of the object. If a numeric, the
value is used to set the threshold of a new Verbose object. If TRUE,
the threshold is set to -1 (minimal). If FALSE, no output is written
(and neither is the R.utils package required).
|
Note that ... must not contain variables with names equal
to the arguments matVersion and onWrite, which were choosen
because we believe they are quite unique to this write method.
Returns (invisibly) the number of bytes written. Any bytes written by any onWrite function are not included in this count.
If specified, the onWrite() function is called before the
data is written to the connection. This function must take a list
argument as the first argument. This will hold the element con
which is the opened connection to be written to.
It will also hold the element length, which specified the
number of bytes to be written. See example for an illustration.
Note, in order to provide the number of bytes before actually
writing the data, a two-pass procedure has to be taken, where the
first pass is immitating a complete writing without writing anything
to the connection but only counting the total number of bytes. Then
in the second pass, after calling onWrite(), the data is written.
Henrik Bengtsson (http://www.braju.com/R/)
readMat().
A <- matrix(1:27, ncol=3) B <- as.matrix(1:10) C <- array(1:18, dim=c(2,3,3)) filename <- paste(tempfile(), ".mat", sep="") writeMat(filename, A=A, B=B, C=C) data <- readMat(filename) str(data) X <- list(A=A, B=B, C=C) stopifnot(all.equal(X, data[names(X)])) unlink(filename) ## Not run: # When writing to a stream connection the receiver needs to know on # beforehand how many bytes are available. This can be done by using # the 'onWrite' argument. onWrite <- function(x) writeBin(x$length, con=x$con, size=4, endian="little"); writeMat(con, A=A, B=B, onWrite=onWrite) ## End(Not run)