Mine.seis: Mine a seismic data base to extract secions of time limited...
In RSEIS: Seismic Time Series Analysis Tools

Mine.seis

R Documentation

Mine a seismic data base to extract secions of time limited data

Description

Mine a seismic data base to extract secions of time limited data

Usage

Mine.seis(at1, at2, DB, grepsta, grepcomp, kind = 1, Iendian=1,
BIGLONG=FALSE, CHOP=TRUE, verbose=FALSE, chtoken=NULL, statoken=NULL, RAW=FALSE)

Arguments

`at1`	time 1 in julian days
`at2`	time 2 in julian days
`DB`	data base structure to searcth through that provides the files where data is to extracted from
`grepsta`	which stations to extract
`grepcomp`	which components to extract
`kind`	kind of data, -1="RDS", 0="RDATA" , 0="RDATA", 1 = "segy", 2 = "sac"
`Iendian`	Endian-ness of the data: 1,2,3: "little", "big", "swap". Default = 1 (little)
`BIGLONG`	logical, TRUE=long=8 bytes
`CHOP`	cut the data to a window using CHOP.SEISN
`verbose`	print out intermediate information for debugging
`chtoken`	channel token for selecting channels (NULL)
`statoken`	station token for selecting stations (NULL)
`RAW`	logical, default=FALSE(convert to volts) , TRUE (return counts intead of volts)

Details

The data base is a list or dataframe containing the files names, the beginning time (t1) and ending time (t2) for each file in the data base. Mine.seis uses grep on the file names to extract specific files from the DB list.

Mine.seis needs to know what format the data was created in: little/big endian and the size of the LONG.

If data was created on a little endian machine but is being read on big endian machine, need to call the endian "swap" for swapping.

If data was created on a machine with LONG=4 bytes, be sure to call the program with BIGLONG=FALSE.

Use sysinfo to findout the system parameters for the local system. You need to know, however, what machine the binary files were created on.

In some situation the chanel name and the station name are not embedded in the file headers - in that case use the token from the file name.

Value

List of seismograms cut from the database

Note

The headers in the digital (segy or SAC) data files may not necessarily match the file names. Note that program JGET.seis extracts the station name and component name from the digital header and does not use the file name. It may be prudent to force the file names and header files to match prior to using Mine.seis. For SEGY files, in LINUX-UNIX, use: rename, segymod (PASSCAL) to modify the headers.

For SAC files, use sac software.

For R-based codes save the files in a format that has the relevant information (DAT format).

Author(s)

Jonathan M. Lees<jonathan.lees.edu>

Examples


data(GH)

DD = data.frame(GH$info)

#### get only vertical traces
WV = which( GH$COMPS=='V' )
L1 = length(WV)

GIVE = vector(mode='list')

for(j in 1:L1 )
{
    i = WV[j]
    AA = DD[i,]
    GIVE[[j]] = list(fn = AA$fn, sta =GH$STNS[i] , comp = GH$COMP[i], 
                     dt = AA$dt, DATTIM = AA, N = AA$n1, units = NA, 
                     coords = NA, amp = GH$JSTR[[i]]  )
}
#### par(mfrow=c(length(GIVE) , 1) )
#   for(i in 1:length(GIVE) ) { plotGH(GIVE[[i]])   }
tdir = tempdir()
for(i in 1:length(GIVE) )
{
    sig = GIVE[[i]]
  d1 =  dateStamp(sig$DATTIM, sep='_')
   nam1 =  paste(d1,sig$sta, sig$comp, sep='_')
    nam2 = paste0(nam1, '.RDS')
    nam3 = paste(tdir, nam2, sep='/')
    saveRDS(file=nam3, sig) 
    }
########################  Now  read files and make the DataBase:
LF  = list.files(path=tdir,pattern='.RDS',  full.names=TRUE)
DB = FmakeDB(LF, kind=-1)
IDB = infoDB(DB)


SAMPseis <- Mine.seis(IDB$at1, IDB$at2, DB, IDB$usta[1:3], IDB$ucomp[1], kind = -1   )

w <- swig(SAMPseis, SHOWONLY=0)

RSEIS documentation built on Sept. 13, 2024, 1:09 a.m.