stream (version 1.0-3)

DSD_ReadStream: Read a Data Stream from File

Description

A DSD class that reads a data stream from a file or any R connection.

Usage

DSD_ReadStream(file, sep=",", k=NA, d=NA, take=NULL, assignment=NULL, 
     loop=FALSE)
close_stream(dsd)

Arguments

file

A file/URL or an open connection.

sep

The character string that separates dimensions in data points in the stream.

k

Number of true clusters, if known.

d

Number of dimensions (only used for print).

take

indices of columns to extract from the file.

assignment

column index for the cluster assignment (class attribute).

loop

If enabled, the object will loop through the stream when the end has been reached. If disabled, the object will warn the user upon reaching the end.

dsd

A object of class DSD_ReadStream.

Value

• An object of class DSD_ReadStream (subclass of DSD_R, DSD).

Details

DSD_ReadStream uses read.table() to read in data from an R connection. The connection is responsible for maintaining where the stream is currently being read from. In general, the connections will consist of files stored on disk but have many other possibilities (see connection).

The position in the file can be reset to the beginning using reset_stream(). The connection can be closed using close_stream().

See Also

DSD, reset_stream,

Examples

# creating data and writing it to disk
dsd <- DSD_Gaussians(k=3, d=5)
write_stream(dsd, "data.txt", n=100, sep=",")

# reading the same data back (as a loop)
dsd2 <- DSD_ReadStream("data.txt", sep=",", loop=TRUE)
dsd2

# clean up
close_stream(dsd2)
file.remove("data.txt")

# example with a part of the kddcup1999 data (take only cont. variables)
file <- system.file("examples", "kddcup10000.data.gz", package="stream")
dsd <- DSD_ReadStream(gzfile(file),
        take=c(1, 5, 6, 8:11, 13:20, 23:41), assignment=42, k=7)
dsd

get_points(dsd,5)


# plot 100 points (projected on the first two principal components)
plot(dsd, n=100, method="pc")

close_stream(dsd)