.\"Copyright 2011 (c) EPFL
.TH EGD_GET_NUMCH 3 2011 "EPFL" "EEGDEV library manual"
.SH NAME
egd_get_numch - Get the number of channels sampled by type
.SH SYNOPSIS
.LP
.B #include <eegdev.h>
.sp
.BI "int egd_get_numch(const struct eegdev* " dev ", int " stype ");"
.br
.SH DESCRIPTION
.LP
\fBegd_get_numch\fP() returns the number of channels of type \fIstype\fP
sampled by the recording device referenced by \fIdev\fP. \fIstype\fP must be
one of the values returned by \fBegd_sensor_type\fP(3).
.SH "RETURN VALUE"
.LP
In case of success, the function returns a non negative value corresponding
to the number of channels of type \fIstype\fP (possibly 0 if the device does
not sample this type of data). Otherwise, \-1 is returned and \fIerrno\fP is
set accordingly.
.SH ERRORS
.LP
\fBegd_get_numch\fP() will fail if:
.TP
.B EINVAL
\fIdev\fP is NULL or \fIstype\fP is not valid value.
.SH "SEE ALSO"
.BR egd_get_cap (3),
.BR egd_sensor_type (3)