.\"Copyright 2010 (c) EPFL
.TH XDF_ADD_EVENT 3 2010 "EPFL" "xdffileio library manual"
.SH NAME
xdf_add_event - Appends an event to the data file
.SH SYNOPSIS
.LP
.B #include <xdfio.h>
.sp
.BI "int xdf_add_event(struct xdf* " xdf ", int " evttype ","
.br
.BI "                  double " onset ", double " dur ");"
.br
.SH DESCRIPTION
.LP
\fBxdf_add_event\fP() appends to the file referenced by the handle \fIxdf\fP
opened for writing an event of type \fIevttype\fP at time \fIonset\fP
lasting for a duration \fIdur\fP expressed in seconds. If the event has no
notion of duration, \fIdur\fP should be set to 0. \fPevttype\fP should be a
value returned by a successful call to \fBxdf_add_evttype\fP(3).
.SH "RETURN VALUE"
.LP
\fBxdf_add_event\fP() returns 0 in case of success. Otherwise \-1 is returned
and \fIerrno\fP is set appropriately.
.SH ERRORS
.TP
.B EINVAL
\fIxdf\fP is NULL or \fIevttype\fP has not been previously created by
\fBxdf_add_evttype\fP(3)
.TP
.B ENOMEM
The system is unable to allocate resources.
.TP
.B EPERM
The file referenced by \fIxdf\fP has not been opened for writing or its
file format does not support events.
.SH "SEE ALSO"
.BR xdf_add_evttype (3)