NAME

     vstak  - module to vertically stack data sets with  weights.
     Useful  for quickly determining difference between input and
     output to a process [use -amp-1].

SYNOPSIS

     vstak [ -N1ntap1 ] [ -N2ntap2 ] [ -Ootap  ]  [  -enetr  ]  [
     -snrst  ]  [ -nsnstr ] [ -nenetr ] [ -rsnrst ] [ -renred ] [
     -ampamp ] [ -norm ] [ -panel ] [ -splice ] [ -S ] [ -R  ]  [
     -V ] [ -? ]

DESCRIPTION

     vstak weights and vertically stacks portions of 2 input data
     sets. Current options are:

      1. default: output = N1 +  amp x N2
      2. -splice: output = N2 where N1 = 0.0
      3. -S vector square: output = N1**2 + (amp x N2)**2
      4. -R vector square root:
          output = sqrt[N1**2 + (amp x N2)**2]

     The normalize flag  may  be  used  with  any  of  the  above
     options.   If  flagged  with -panel the routine assumes that
     the N2 dataset contains one trace records.  A given N2 trace
     will  be  stacked  with  each  trace  of an N1 input record.
     There  should be the same number of records in both  the  N1
     and N2 datasets.  The N2 dataset amplitude may be multiplied
     by a user define amplitude  prior  to  addition  to  the  N1
     input.   If  you wish to pipe into N2 you will need to be in
     IKP or used a named pipe.  If  N2  and  the  output  dataset
     names  are the same then the contents of N1 will be added to
     N2.  This feature allows  accumulation  of  vertical  stacks
     over several runs.  If the dataset name used for N2 and O in
     this instance does not yet exist, it will be created.   When
     using  the  N2 = output name option piping is NOT allowed as
     you must back up on the output dataset to  drop  the  summed
     trace.

     vstak gets both its data and  its  parameters  from  command
     line  arguments.  These arguments specify the input, output,
     the start and end times, the start and end traces, start and
     end  records,  N2  amplitude multiplier, splice option flag,
     panel option flag, sum of squares option  flag,  vector  sum
     option flag, and verbose printout flag if desired.


  Command line arguments
     -N1 ntap1 [default = stdin]
          Enter the input data set name or file immediately after
          typing  -N1.   This  input file should include the com-
          plete path name if the  file  resides  in  a  different
          directory.   Example -N1/vsp/dummy tells the program to
          look for file 'dummy' in directory 'vsp'.

     -N2 ntap2 [default = none]
          Enter the input data set name or file immediately after
          typing  -N2.  ntap2  can  be the same as otap but ntap1
          must be different from otap.  This  input  file  should
          include the complete path name if the file resides in a
          different directory.  Example -N1/vsp/dummy  tells  the
          program to look for file 'dummy' in directory 'vsp'.

     -O otap [default = stdout]
          Enter the output data  set  name  or  file  immediately
          after  typing -O. This output file is not required when
          piping the output to another process.  If ntap2 is  the
          same  as otap then piping on output is disallowed.  The
          output data set also requires the full path  name  (see
          above).

     -s ist
          Enter the start time (ms).  The default is  the  begin-
          ning of the trace.

     -e iend
          Enter the end time (ms).  The default is the end of the
          trace.

     -ns nstr
          Enter the start trace number. Trace numbers below  this
          value will not be processed. The default is 1.

     -ne netr
          Enter the end trace number.  Trace numbers  above  this
          value  will  not be processed.  The default is the last
          trace number on the input data set.

     -rs nrst
          Enter start record number.  Default value is the  first
          record.

     -re nred
          Enter end record number.  Default value is last record.

     -amp amp
          Enter the multiplier to be applied to  the  N2  dataset
          [i.e. in the default mode O = N1 + amp*N2]

     -norm
          Enter the command line argument '-norm' to get normali-
          zation  of input values when  both N1 and N2 input sam-
          ples are non-zero [i.e.O = (N1 + (amp*N2))/2]


     -splice
          Enter the command line argument  '-splice'  to  replace
          zero  values in N1 with data from N2.  You may use nor-
          malization and  an    amplitude  multiplier  with  this
          option if you should so choose.

     -panel
          Enter the command line argument  '-panel'  to  activate
          the panel option.  In this option the N2 dataset should
          have single trace records  with  one  record  for  each
          record  input  on  N1.  The N2 trace will be stacked to
          each trace of the associated N1 record.  The -S, -R and
          -norm options are allowed here.  You may not use the N2
          = output option for in this  instance  the  N1  and  N2
          datasets  do  NOT  have  the  same number of traces per
          record.

     -S   Enter the command line argument '-S' to get the  vector
          square:  O = N1**2 + (amp*N2)**2

     -R   Enter the command line argument '-R' to get the  vector
          square root :  O = sqrt(N1**2 + (amp*N2)**2)

     -V   Enter the command line argument '-V' to get  additional
          printout.

     -? -h -help
          Enter the command line argument '-?'   or  '-h'  or  '-
          help'  to get online help. The program terminates after
          the help screen is printed.

BUGS

      Unknown

SEE ALSO

     mvstak(1) mknod(1)

AUTHOR

     P. Gutowski, P. Garossino [ATTC]

COPYRIGHT

     copyright 2001, Amoco Production Company
               All Rights Reserved
          an affiliate of BP America Inc.