tomwalters@0: .TH GATE 1 "15 September 1993"
tomwalters@0: 
tomwalters@0: .SH NAME
tomwalters@0: gate \- gate specific numbers from the input stream.
tomwalters@0: 
tomwalters@0: .SH SYNTAX 
tomwalters@0: gate  [options]  [file]
tomwalters@0: 
tomwalters@0: .SH DESCRIPTION
tomwalters@0: 
tomwalters@0: Numbers in the input stream within given gate ranges are replaced by a
tomwalters@0: particular <value>. Both time and amplitude ranges may be specified.
tomwalters@0: The <value> may be a real number or the result of a particular <operation>.
tomwalters@0: Results are written on the stdout in numbers of the same type as that
tomwalters@0: selected for input.
tomwalters@0: 
tomwalters@0: .SH OPTIONS
tomwalters@0: 
tomwalters@0: 1. xrange, yrange
tomwalters@0: 
tomwalters@0: The `xrange' specifies the time range and the `yrange' specifies the
tomwalters@0: amplitude range for the gating operation. Ranges are specified:
tomwalters@0: 
tomwalters@0: .nf
tomwalters@0: 	xrange=a[-b]
tomwalters@0: 	yrange=a[-b]
tomwalters@0: .fi
tomwalters@0: 
tomwalters@0: The upper limit `b' is optional, and when it is missing then the range
tomwalters@0: is a single number, otherwise `a' and `b' are inclusive range limits.
tomwalters@0: The xrange limits are in samples (no units) or may take time units (s or ms),
tomwalters@0: in which case they are converted to samples using the given `samplerate'
tomwalters@0: option. The yrange limits are real numbers.
tomwalters@0: The strings "min" and "max" are recognised as extreme limits: the start and
tomwalters@0: end of the input stream for the xrange, and the most positive and negative
tomwalters@0: amplitudes for the yrange.
tomwalters@0: 
tomwalters@0: 2. value
tomwalters@0: 
tomwalters@0: The <value> may be a real number or an <operation>,
tomwalters@0: in which case all input numbers within the gate range are operated on as
tomwalters@0: appropriate. Abbreviated forms of the operation names are allowed.
tomwalters@0: 
tomwalters@0: .nf
tomwalters@0: <operation>:
tomwalters@0:     exclude     exclude numbers in gate range from output
tomwalters@0:     negate      negate numbers in gate range
tomwalters@0:     count       print count of numbers in gate range on the stderr
tomwalters@0: .fi
tomwalters@0: 
tomwalters@0: 3. type
tomwalters@0: 
tomwalters@0: The input and output datatype may be: char, short, int, float, double, ASCII.
tomwalters@0: Ascii input is taken to be one number per line.
tomwalters@0: 
tomwalters@0: .SH EXAMPLES
tomwalters@0: 
tomwalters@0: 1. Replace all numbers <=0 by value 0  (ie. half-wave rectification).
tomwalters@0: 
tomwalters@0: .nf
tomwalters@0: 	gate yrange=min-0 val=0  file
tomwalters@0: .fi
tomwalters@0: 
tomwalters@0: 2. Replace all numbers <=0 by their inverse (ie. full-wave rectification).
tomwalters@0: 
tomwalters@0: .nf
tomwalters@0: 	gate yrange=min-0 val=neg  file
tomwalters@0: .fi
tomwalters@0: 
tomwalters@0: 3. Gate the onset of a signal: replace the first 20ms with zeroes.
tomwalters@0: 
tomwalters@0: .nf
tomwalters@0: 	gate xrange=0-20ms yrange=min-max val=0 file
tomwalters@0: .fi
tomwalters@0: 
tomwalters@0: 4. Exclude all numbers <=0
tomwalters@0: 
tomwalters@0: .nf
tomwalters@0: 	gate yrange=min-0  val=exclude file
tomwalters@0: .fi
tomwalters@0: 
tomwalters@0: 5. Exclude all numbers >0
tomwalters@0: 
tomwalters@0: .nf
tomwalters@0: 	gate yrange=1-max val=exclude file
tomwalters@0: .fi
tomwalters@0: 
tomwalters@0: 6. Delete lines 4 to 8 inclusive from ascii input (lines numbered 0,1,2,...)
tomwalters@0: 
tomwalters@0: .nf
tomwalters@0:     gate type=ASCII xrange=4-8 yrange=min-max val=exclude  file
tomwalters@0: .fi
tomwalters@0: 
tomwalters@0: 7. Replace all numbers in the yrange -1 to +1 inclusive by 0
tomwalters@0: 
tomwalters@0: .nf
tomwalters@0: 	gate yrange=-1-1 val=0  file
tomwalters@0: .fi
tomwalters@0: 
tomwalters@0: 8. Replace all instances of number 10 by -10
tomwalters@0: 
tomwalters@0: .nf
tomwalters@0: 	gate yrange=10 val=-10  file
tomwalters@0: .fi
tomwalters@0: 
tomwalters@0: 9. Print a count of all numbers = 0
tomwalters@0: 
tomwalters@0: .nf
tomwalters@0: 	gate yrange=0 val=count file
tomwalters@0: .fi
tomwalters@0: 
tomwalters@0: 10. Print a count of all numbers < 0
tomwalters@0: 
tomwalters@0: .nf
tomwalters@0: 	gate yrange=min--1  val=count file
tomwalters@0: .fi
tomwalters@0: 
tomwalters@0: 
tomwalters@0: .SH "SEE ALSO"
tomwalters@0: .LP
tomwalters@0: options edwave step merge
tomwalters@0: .SH COPYRIGHT
tomwalters@0: .LP
tomwalters@0: Copyright (c) Applied Psychology Unit, Medical Research Council, 1995
tomwalters@0: .LP
tomwalters@0: Permission to use, copy, modify, and distribute this software without fee 
tomwalters@0: is hereby granted for research purposes, provided that this copyright 
tomwalters@0: notice appears in all copies and in all supporting documentation, and that 
tomwalters@0: the software is not redistributed for any fee (except for a nominal 
tomwalters@0: shipping charge). Anyone wanting to incorporate all or part of this 
tomwalters@0: software in a commercial product must obtain a license from the Medical 
tomwalters@0: Research Council.
tomwalters@0: .LP
tomwalters@0: The MRC makes no representations about the suitability of this 
tomwalters@0: software for any purpose.  It is provided "as is" without express or 
tomwalters@0: implied warranty.
tomwalters@0: .LP
tomwalters@0: THE MRC DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING 
tomwalters@0: ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL 
tomwalters@0: THE A.P.U. BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES 
tomwalters@0: OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, 
tomwalters@0: WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, 
tomwalters@0: ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS 
tomwalters@0: SOFTWARE.
tomwalters@0: