RSEIS (version 4.2-4)

makeDB: Create a seismic Waveform Database

Description

Create a seismic Waveform Database

Usage

makeDB(path=".", pattern="R", dirs="", kind = 1,
Iendian=1, BIGLONG=FALSE)
FmakeDB(LF2, kind =1, Iendian=1, BIGLONG=FALSE)

Value

list:

fn

file name

yr

year

jd

julian day

hr

hour

mi

minute

sec

second

dur

duration, seconds

t1

time 1 in Epoch days

t2

time 2 in Epoch days

sta

station name

comp

component name

dt

sample rate, seconds

Arguments

path

character, Path to directory where files and directories exist

pattern

character, pattern for listing of files

dirs

character, vector of directories to be scanned

kind

kind of data: RDS=-1, R(DAT)=0, segy=1; sac=2

Iendian

default=1, Endian-ness of the data: 1,2,3: "little", "big", "swap". Default = 1 (little)

BIGLONG

logical, TRUE means long=8 bytes

LF2

list of files

Author

Jonathan M. Lees<[e-mail]>

Details

The files are typically located in a directory structure created by programs like ref2segy, a PASSCAL program for downloading data in the field. Each file contains one seismogram, with a header. makeDB reads in all the headers and creates a list of meta-data for later use in RSEIS.

"kind" can be numeric or character: options are 'RDS', 'RDATA', 'SEGY', 'SAC', corresponding to (-1, 0, 1, 2).

Uses readBin to extract data in SAC format. user must know what kind of machine the data was created on for I/O purposes.

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.

If the base directory, or the subdirectories, contain files that are not seismic data then care must be taken. Perhaps use FmakeDB to explicitly names the files for the DataBase.

If using FmakeDB a simple vector of files (full path names) should be provided.

The origin year, used for getting the Epoch year, is stored as attribute origyr.

See Also

setupDB, Mine.seis , getseis24, plotseis24, EPOCHday, swig

Examples

##########  to illustrate, we make a set of individual seismograms
data(GH)
L1 = length(GH$JSTR)
DD = data.frame(GH$info)

GIVE = vector(mode='list')

for(i in 1:L1)
{
AA = DD[i,]
GIVE[[i]] = 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]]  )
}

###########  save the seismic data in a temporary directory
####   each trace in a separate file
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)