SUIO

A Fortran library for input/output of SU files, independent from the Seismic Unix package

Install

make
make install

Compile

your_fortran_compiler -o main.e main.f90 -I/path/to/include -L/path/to/lib -lsuio

SU IO module

Quick reference

use suio, only: SuFile, SuTrace, SuHeader, su_input, su_output
type(SuFile):: sf, so
type(SuTrace):: trc
type(SuHeader):: sh
integer:: fldr, tracf, ns, dt, ntr
real,allocatable:: array(:)
! set ns and allocate data array
allocate(array(ns))

! open: read
sf = su_input('input.su',ns=ns,ntr=ntr)
sf = SuFile('input.su','r')
ns = sf%ns()
ntr= sf%ntr() ! for file input only (not for stdin input)

! open: write
so = su_output(xdr=.true.) ! stdout, XDR format
so = SuFile('output.su','w')

! close
call sf%close()

! read trace
do itr=1,ntr
    call sf%read(trc)
enddo

! read header
do itr=1,ntr
    call sf%read(sh,itr)
enddo

! write trace
do itr=1,ntr
    call sf%write(trc)
enddo

! read header, keyword, data
call trc%get(fldr=fldr, tracf=tracf, header=sh, data=array)

! write header, keyword, data
call trc%set(fldr=fldr, tracf=tracf, header=sh, data=array)

! trace, header generator
trc = SuTrace(header=sh, fldr=fldr, ns=ns, dt=dt, data=array)
sh = SuHeader(fldr=fldr, ns=ns, dt=dt)

SuTrace and SuFile handle

SU IO handles su files using two derived data types: SuFile and SuTrace.

use suio, only: SuFile, SuTrace, su_input, su_output
type(SuFile):: sf
type(SuTrace):: trc

Input

Opening a file

We use su_input function or SuFile generator to open an SU file for input.

type(SuFile):: sf
! use su_input function
sf = su_input(filename,xdr,ns,ntr)

! or the generator
sf = SuFile(filename,mode='r',xdr,ns,ntr)

Their interfaces are

!! file input
type(SuFile) function su_input(filename, xdr, ns, ntr)
character(len=*),intent(in):: filename
logical,intent(in),optional:: xdr
integer,intent(out),optional:: ns, ntr
end function

!! standard input
type(SuFile) function su_input(xdr, ns)
logical,intent(in),optional:: xdr
integer,intent(out),optional:: ns
end function

!! file input/output
type(SuFile) function SuFile(filename, mode, xdr, ns, ntr)
character(len=*),intent(in):: filename
character,intent(in):: mode
logical,intent(in),optional:: xdr
integer,intent(out),optional:: ns, ntr
end function

!! standard input/output
type(SuFile) function SuFile(mode, xdr, ns)
character,intent(in):: mode
logical,intent(in),optional:: xdr
integer,intent(out),optional:: ns
end function

All arguments are optional.
filename is an su file name to read. If we omit fileanme, the module reads traces from the standard input.
xdr=.false. is a logical value. Default value is .false. and it means that the su file is in native binary format. Use xdr=.true. to read XDR-formatted su file.
ns is an integer output and it is the number of samples in a trace.
ntr is an integer output and it is the number of traces in the su file. ntr is not available for su files from the standard input.
mode should be 'r' or 'R' for input, 'w' or 'W' for output.

Reading traces

Once we open an SU file, we can read data trace by trace using su%read, su%fread, and su%trace. Their interfaces are

subroutine read(sf,trc,itr,eof)
type(SuFile),intent(inout):: sf
type(SuTrace),intent(out):: trc
integer,intent(in),optional:: itr
logical,intent(out),optional:: eof
end subroutine

logical function fread(sf,trc,itr)
type(SuFile),intent(inout):: sf
type(SuTrace),intent(out):: trc
integer,intent(in),optional:: itr
end function

type(SuTrace) function trace(sf,itr)
type(SuFile),intent(inout):: sf
integer,intent(in),optional:: itr
end function

Optional input itr is the trace number. We can read a specific trace using itr. If we omit itr, the module reads traces sequentially from the first trace.
Optional output eof is .true. at the end of a file, while fread is .false. at the end of a file.

Examples:

type(SuTrace):: trc

! we can use sf%read subroutine
! ntr is from su_input or SuFile generator
do itr=1,ntr
    call sf%read(trc)
enddo

! or su%trace function
do itr=1,ntr
    trc = sf%trace()
enddo

! or sf%fread function which returns .true. after success and .false. at the end of file. This function can be used with su files from standard input.
do while( sf%fread(trc) )
    !! process
enddo

Reading trace headers only

We can use SuHeader type to read a trace header only.

type(SuHeader):: sh

Routines for reading header are similar to those for reading traces. But we use SuHeader type instead of SuTrace and the trace number itr is not optional.

subroutine read(sf,sh,itr,eof)
type(SuFile),intent(inout):: sf
type(SuHeader),intent(out):: sh
integer,intent(in):: itr
logical,intent(out),optional:: eof
end subroutine

logical function fread(sf,sh,itr)
type(SuFile),intent(inout):: sf
type(SuHeader),intent(out):: sh
integer,intent(in):: itr
end function

type(SuHeader) function header(sf,itr)
type(SuFile),intent(inout):: sf
integer,intent(in):: itr
end function

Reading header keywords and data

We use get subroutine and functions with keyword name to obtain header values

type(SuTrace):: trc
type(SuHeader):: sh
integer:: fldr, trace, sx
real:: f1
real,allocatable:: arr(:)

! read trace
! ...

allocate(arr(ns))

! using 'get' subroutine
call trc%get('fldr',fldr)
call trc%get('f1',f1)

! We can use 'get' subroutine to read trace data (without header)
call trc%get(arr)
! or we can use 'data' function
arr = trc%data()

! We can read multiple header values at once. This one is convenient.
call trc%get(fldr=fldr, tracf=tracf, sx=sx, f1=f1, data=arr)

! Or we can use functions named by the keywords
fldr = trc%fldr()
f1 = trc%f1()

! If we want whole header,
sh = trc%header()
call trc%get(header=sh)

Output

Generating an SU trace

We need traces to write su files.

type(SuTrace):: trc
type(SuHeader):: sh
integer:: ns=3000, dt=4000, sx=10
real:: arr(ns)

! we can use SuHeader type
sh = SuHeader(ns=ns, dt=dt)
trc = SuTrace(header=sh, data=arr)

! or we can generate the SuTrace without SuHeader
trc = SuTrace(ns=ns, dt=dt, sx=sx, data=arr)

Writing header keywords and data

We use set subroutine to set header, keywords, and data.

call sh%set('sx',sx)
call sh%set(sx=sx, dt=dt)
call trc%set('sx',sx)
call trc%set(sx=sx, dt=dt, data=arr)
call trc%set(header=sh)

Opening a file

We open a file for writing to write traces.

type(SuFile):: sf
! use su_output function
sf = su_output(filename,xdr)

! or the generator
sf = SuFile(filename,mode='w',xdr)

Interfaces are

!! file output
type(SuFile) function su_output(filename, xdr)
character(len=*),intent(in),optional:: filename
logical,intent(in),optional:: xdr
end function

!! standard output
type(SuFile) function su_output(xdr)
logical,intent(in),optional:: xdr
end function

Writing traces

Writing is simple. Always write sequentially using so%write.

type(SuFile):: sf, so, sd
type(SuTrace):: trc
! open ...
do while( sf%fread(trc) )
    call so%write(trc)
enddo

The interface is

subroutine write(sf,trc)
type(SuFile),intent(inout):: sf
type(SuTrace),intent(in):: su
end subroutine

Close

After we are done with a SuFile, we close it.

call sf%close()

! we can close multiple files (up to 10) at once.
call su_close(sf1,sf2,sf3...)

Examples

suwind

! suwind key=fldr min=10 max=20 < input.su > output.su
program suwind
use suio
type(SuFile):: sf, so
type(SuTrace):: trc
character(len=4):: keyword=“fldr”
integer:: keymin=10, keymax=20, keyval

sf = su_input()
so = su_output()
do while( sf%fread(trc) )
       call trc%get(keyword,keyval)
       if(keymin <= keyval .and. keyval <= keymax) call so%write(trc)
enddo
call su_close(sf, so)
end program

supaste

! sustrip head=header < input_header.su > /dev/null
! sustrip < input_data.su > data.bin
! supaste ns=1000 head=header < data.bin > output.su

program supaste
use suio
type(SuFile):: sh, sd, so
type(SuTrace):: trc
integer:: itr, ntr, ns

sh = su_input(“input_header.su”, ntr=ntr)
sd = su_input(“input_data.su”, ns=ns)
so = su_output(“output.su”)

do itr = 1,ntr
    trc = sd%trace(itr)
    call trc%set(header=sh%header(itr), ns=ns)
    call so%write(trc)
enddo

call su_close(sh, sd, so)
end program

sunewtoold (XDR to native binary)

program suNewToOld
use suio
type(SuFile):: sf, so
type(SuTrace):: trc

sf = su_input(xdr=.true.)
so = su_output(xdr=.false.)
do while( sf%fread(trc) )
    call so%write(trc)
enddo
call su_close(sf,so)
end program

pkgpl/SUIO

SUIO

Install

Compile

SU IO module

Quick reference

SuTrace and SuFile handle

Input

Opening a file

Reading traces

Reading trace headers only

Reading header keywords and data

Output

Generating an SU trace

Writing header keywords and data

Opening a file

Writing traces

Close

Examples

suwind

supaste

sunewtoold (XDR to native binary)