NAME
replace - replace, detect,do math, set a velocity gradient,
apend or insert a function, set a max/min value and swap
values on a range of samples in selected records/traces with
a user specified value or from a pair of headerwords. These
functions may useful for any type of USP formatted dataset.
SYNOPSIS
replace [ -Nntap ] [ -N2ntap ] [ -Ootap ] [ -HW1 or -hw1
hdrwd1 ] [ -HW2 or -hw2 hdrwd2 ] [ -HW3 or -hw3 hdrwd3 ] [
-HW4 or -hw4 hdrwd4 ] [ -HW5 or -hw5 hdrwd4 ] [ -h4scale ] [
-sist ] [ -eiend ] [ -rsrecordstart ] [ -rerecordend ] [
-nstracestart ] [ -netraceend ] [ -valueval ] [ -biasvbias ]
[ -scalevscl ] [ -voinitvel ] [ -vgradvelgrad ] [ -refrefer-
ence ] [ -swapaval1 ] [ -swapbval2 ] [ -minminval ] [ -max-
maxval ] [ -top ] [ -bot ] [ -I ] [ -M ] [ -D ] [ -V ] [ -h,
-? ]
DESCRIPTION
replace either replaces, detects, does simple math, or sets
a gradient on a range of samples defined by start and end
times (or depths) of selected traces or ranges of traces
with a user specified value. The math involves adding a bias
to the current value and/or scaling the curent value. The
gradient option involves the definition of a starting velo-
city and gradient with a reference point. The alteration,
whatever it is, is done either on isolated traces or on
ranges of traces defined by record-trace number pairs, or
globally across the entire data set. DATA NOT DIRECTLY
AFFECTED BY THE REPLACEMENT PROCESS IS PASSED UNAFFECTED.
Replace has the option of time or depth range sample con-
straining, using values located in the user defined header-
words. The user can apply USP program recshift (for exam-
ple) and two separate XSD pick files to define an upper and
lower limit of contraint and place the time or depth values
in any two headerwords to be flagged in program replace for
value constraining. Data not directly affecteded by the
contraint option is passed unaffected.
While performing a replace operation, replace has the option
to read a user defined null value from the user defined
header word and pass the trace with no change. The user
must be sure to define the null value on command line. The
program will look for this null value in either the user
defined HW1 or HW2.
replace gets both its data and its parameters from command
line arguments. These arguments specify the input, output,
the optional file name containing record and trace numbers,
the replacement window, the replacement value, and verbose
printout, if desired.
Command line arguments
-N ntap
Enter the input data set name or file immediately after
typing -N unless the input is from a pipe in which case
the -N entry must be omitted. This input file should
include the complete path name if the file resides in a
different directory. Example -N/b/vsp/dummy tells the
program to look for file 'dummy' in directory '/b/vsp'.
-N2 ntap
Enter the secondary input data set name or file immedi-
ately after typing -N2. This is the dataset the pro-
gram will use to replace values from. This data set
will be apended to the data set from -N. If the -I is
used, this data set will be inserted into the file from
-N.
-O otap
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. The output data
set also requires the full path name (see above).
-s ist
Enter the global start time (or depth) of the replace-
ment. Default = trace start.
-e iend
Enter the global end time (or depth) of the replace-
ment. Default = trace end.
-rs recordstart
Enter the start record for record constrained replace-
ment. Default = first record.
-rs recordend
Enter the end record for record constrained replace-
ment. Default = last record.
-ns tracestart
Enter the start trace for trace constrained replace-
ment. Default = first trace.
-ne traceend
Enter the end trace for trace constrained replacement.
Default = last trace.
-HW1 or -hw1 hdrwd1
Enter the first trace header word menmonic to be
tested. No default.
-HW2 or -hw2 hdrwd2
Enter the second trace header word menmonic to be
tested. No default.
-HW3 or -hw3 hdrwd3
Enter the third trace header word menmonic to be
tested. This is to be used when storing the reference.
No default.
-HW4 or -hw4 hdrwd4
Enter the fourth trace header word menmonic to be
tested. This is to be used to replace trace values
between times in -HW1 and -HW2 with the value stored at
-HW4. Not required if you are using -hw1 -hw2 and a
math option, for instance -scale[] and/or -bias[]. If
you do input a -hw4[] on the commandline it will result
in this option overriding all other options. For
instance your math stuff will not get done, only the
replacement will be accomplished.
-HW5 or -hw5 hdrwd5
Enter the trace header word menmonic to be tested. If
used, the gradient mode will be enabled. The gradient
-vgrad[] should be completed on the command line. The
v0 for each trace will come from this header location
allowing a variable v0 across your dataset.
-h4scale
If present on the command line use the value in -hw4 to
scale the data between -hw1 and -hw2. This option is
only valid when -hw4 is specified on the command line
as well.
-value val
Enter the value to replace. Default = 0.0.
-bias vbias
Enter the bias to add to the current sample value.
Default = 0.0
-scale vscl
Enter the factor by which to scale the current sample
value. Default = 1.0
-vo initial velocity
Enter the initial velocity when replacing with a gra-
dient. Default = 0.0
-vgrad velocity gradient
Enter the velocity gradient when replacing with a gra-
dient. Default = 0.0
-ref referecnce elevation
Enter the reference elevation when replacing with a
gradient. Default = top of replacement window
-swapa val_a
Enter the value which is being replaced by swapb.
-swapb val_b
Enter the value which is replaceing swapa.
-min minval
Enter the minimum allowable value for the dataset.
Default is to repalce any values less than minval with
minval. If -value is used then values less than minval
are replaced with val.
-max maxval
Enter the maximum allowable value for the dataset.
Default is to repalce any values greater than maxval
with maxval. If -value is used then values greater
than maxval are replaced with val.
-top Enter the command line argument '-top' to start the min
or max replacement operation from the top of the trace
and work downward, ceasing replacement after the first
violation of the min or max constraint.
-bot Enter the command line argument '-bot' to start the min
or max replacement operation from the bottom of the
trace and work upward, ceasing replacement after the
first violation of the min or max constraint.
-I Enter the command line argument '-I' to indicate that
the replacement operation is file insertion. If com-
bined with an entry for -value[] then any sample in the
-N[] dataset will be replaced by the same sample from
the -N2[] dataset. Default action is to replace -N[]
with -N2[] inside constraints.
-D Enter the command line argument '-D' to indicate that
the replacement operation is to detect the value given
in the -value option and replace it with the previous
sample value (a type of extrapolation).
-M Enter the command line argument '-M' to create a mask
by forcing all non zero sample values to be 1.0
-? Enter the command line argument '-?' to get online
help. The program terminates after the help screen is
printed.
DISCUSSION
This program will not allow for the editing of a volume.
The start and end time and Index Contraints (trace record)
are used as constraints on the replacement. This gives the
user the ability to constrain model replacements with as
many variables as are available.
The following examples show how to use the program:
For a basic gradient function over all the data starting
with 1500 and having a gradient of 3.2
replace -Ninfile -Ooutfile -vo1500 -vgrad3.2
To to do the same but restrict it within traces 200 and 350
and also restrict the gradient to a time of 1000ms and 2000
ms.
replace -Ninfile -Ooutfile -vo1500 -vgrad3.2 -ns200 -ne350
-s1000 -e2000
To perform the same gradient restrict it to times written in
header words TVPT01 and TVPT02.
replace -Ninfile -Ooutfile -vo1500 -vgrad3.2 -Hw1TVPT01
-Hw2TVPT02
To apend a funciton (either 1 fuction to all the data or a
complete volume). This will apend file2 at the end of
file1.
replace -Nfile1 -N2file2 -Ooutfile
To insert any part of file2 into file1 (similar to apend-
ing).
replace -Nfile1 -N2file2 -Ooutfile -I
To replace trace values (a velocity function) between times
specified by -HW1 (TVPT01) and -HW2 (TVPT02) with the value
stored at -HW4 (TVPT20).
replace -Ninfile -Ooutfile -HW1TVPT01 -HW2TVPT02 -HW4TVPT20
To scale trace values (a velocity function) between times
specified by -HW1 (TVPT01) and -HW2 (TVPT02) by 10 and
adding 1540 using -scale and -bias.
-bias 1540.0
replace -Ninfile -Ooutfile -hw1 TVPT01 -hw2 TVPT02 -
scale 10.0
To replace all values of 10.3 in dataset -N[] with values
from dataset -N2[].
replace -N data1 -N2 data2 -value 10.3 -I -O dataout
All other fuctionality is similar to these examples.
Replace also have very useful min/max options which can
easily be use for QC of data (i.e. ensuring reasoable
values). The above examples are the basic constraints that
the user can apply when using replace.
BUGS
unknown
ALSO SEE
recshift, scale, vstak, ttothen, vomit, velin, vi3d, rest,
flatten, horvel, horvel3d
AUTHOR
James M. Gridley
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