% Generated by roxygen2: do not edit by hand
% Please edit documentation in R/foreign.R
\name{read_graph}
\alias{read_graph}
\alias{read.graph}
\alias{LGL}
\alias{Pajek}
\alias{GraphML}
\alias{GML}
\alias{DL}
\alias{UCINET}
\title{Reading foreign file formats}
\usage{
read_graph(
  file,
  format = c("edgelist", "pajek", "ncol", "lgl", "graphml", "dimacs", "graphdb", "gml",
    "dl"),
  ...
)
}
\arguments{
\item{file}{The connection to read from. This can be a local file, or a
\code{http} or \code{ftp} connection. It can also be a character string with
the file name or URI.}

\item{format}{Character constant giving the file format. Right now
\code{as_edgelist}, \code{pajek}, \code{graphml}, \code{gml}, \code{ncol},
\code{lgl}, \code{dimacs} and \code{graphdb} are supported, the default is
\code{edgelist}. As of igraph 0.4 this argument is case insensitive.}

\item{\dots}{Additional arguments, see below.}
}
\value{
A graph object.
}
\description{
The \code{read_graph} function is able to read graphs in various
representations from a file, or from a http connection. Currently some
simple formats are supported.
}
\details{
The \code{read_graph} function may have additional arguments depending on
the file format (the \code{format} argument). See the details separately for
each file format, below.
}
\section{Edge list format}{
 This format is a simple text file with numeric
vertex ids defining the edges. There is no need to have newline characters
between the edges, a simple space will also do.

Additional arguments: \describe{ \item{n}{The number of vertices in the
graph. If it is smaller than or equal to the largest integer in the file,
then it is ignored; so it is safe to set it to zero (the default).}
\item{directed}{Logical scalar, whether to create a directed graph. The
default value is \code{TRUE}.} }
}

\seealso{
\code{\link{write_graph}}
}
\author{
Gabor Csardi \email{csardi.gabor@gmail.com}
}
\keyword{graphs}
