NAME
sisort3d - output sorted traces from indexed 3D data set
SYNOPSIS
sisort3d [ -Nntap ] [ -Ootap ] [ -ntable ] [ -eiend ] [
-lnst ] [ -mnend ] [ -didel ] [ -G ] [ -S ] [ -D ] [ -L ] [
-X ] [ -orig ] [ -V ] [ -? ]
DESCRIPTION
sisort3d generates sorted traces from the input 3D data set
and the appropriate entry from the sort table output by
presort3d (no, you can't use tables built using presort).
The assumption here is that the sort table is correct which
means that presort3d was run on correctly indexed data (see
presort3d man page).
Another use is to sort 2D data for the case where lines are
very long and exceed the UNIX file size limit (~2Gb) or have
to be distributed over multiple file systems. In this appli-
cation sisort3d must use the sort table generated by
presort3d. These sort tables cannot be read by sisort, the
regular 2D sorting routine.
sisort3d fills in the the following line header words for
use in downstream processing:
CDPFld - maximum number of live DI traces in a common DI
gather
APIWN9 - the sort type specified on cmd line (D, L, ...)
APIWNA - the primary sort type (D, L, ...)
APIWNB - the secondary sort type (L, D, ...)
If the primary and secondary sort type is D,L then expect
the data to come at you DI by DI, each DI having all LIs; if
the primary and secondary sort type is L,D then expect the
data order to be LI by LI, each LI having all DIs. The
first is accessing the data in crossline order; the second
is accessing the data in inline order.
Bin-based sorting is accomplished using the tools sr3d1 and
sr3d2. sr3d1 takes the place of presort3d for indexed-based
sorting; sr3d2 does the actual sorting.
Note: you must be able to store the data on disk. If you
can't then get more disk space - it's cheap and getting
cheaper (a lot cheaper than people's time.
Note: incomplete output records will be padded on the right
with zero traces flagged as dead. If the dead traces must
be in their proper places then the user must stream the data
into disort with the proper command line arguments.
Note: you cannot pipe into sisort3d. The data must reside on
disk.
sisort3d gets both its data and its parameters from command
line arguments. These arguments specify the input, output,
end time, sort table, sort type, renumber option, and ver-
bose printout, if desired.
Command line arguments
-N ntap
Enter the input data set name(s) or file(s) immediately
after typing -N You cannot pipe data into sisort3d it
requires data on disk within which to move a pointer (a
pointer cannot exist in a sequential pipe). If the data
lie on several disk partitions then the names should be
input using repeated -N[] command line arguments in the
order in which the data partitions were filled up, i.e.
you must not for instance have the last partition of
the 3D line as the first -N[]; it must be the last
-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).
-n table
Enter the name of the sort table generated by
presort3d.
-e iend
Enter the end time of the output traces in ms (default
= last sample)
-l nst
Enter the start index to be output, i.e. if -D option
(cdp sort) was specified then nst will be the first cdp
output (default = first index)
-m nend
Enter the last index to be output (default = last on
input)
-d idel
Enter the index increment to be output: only indices
that are an exact multiple of idel will be output
(default = 1, i.e. every index)
-G -S -D -L -X
-G causes common receiver sorted traces to be output
-S causes common source sorted traces to be output
-D causes common depth (DI) sorted traces to be output
-L causes common line (LI) sorted traces to be output
-X causes common offset sorted traces to be output
NOTE: use only one of the above flags
NOTE: in the case of arbitrary sort words in presort
the five sort indices are accessed in the order -G, -S,
-D, -L
-orig
Include on command line if out traces and records are
to retain their original numbers in positions 107
(TrcNum) and 106 (RecNum) of the trace header.
-V Enter the command line argument '-V' to get additional
printout.
-? Enter this (or '-?' if you are running in c-shell) to
get online help. The program will terminate after
printing this.
EXAMPLES
Given that data.tbl is the output from presort3d:
1. inline
sisort3d -Nindata -ndata.tbl -L | ...
2. crossline
sisort3d -Nindata -ndata.tbl -D | ...
3. index limit - output lines 4 - 7
sisort3d -Nindata -ndata.tbl -L -l4 -m7 4. index increment -
output every 50th DI and expand results into equal width
records
sisort3d -Nindata -ndata.tbl -L -d50 | pack3d | ...
where the output from pack3d could be piped into a velspec
for velocity analysis on every 50th DI. To build a sort
table on a very long 2D data set that requires 2 disk parti-
tions:
presort3d -Nindata1 -Nindata2 -Hw4DphInd -nsort_table R
Then, to do the sort on this data:
sisort3d -Nindata1 -Nindata2 -nsort_table -L
So, for vey long 2D lines the input data does not have to be
contiguous on disk.
SEE ALSO
disort, presort3d, pack3d, sr3d1, sr3d2
COPYRIGHT
copyright 2001, Amoco Production Company
All Rights Reserved
an affiliate of BP America Inc.
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