JGET.seis {RSEIS} | R Documentation |
This fuction calls c-routines to read in ‘segy’, ‘sac’.
JGET.seis(fnames, kind = 1, Iendian=1, BIGLONG=FALSE , HEADONLY=FALSE, PLOT = FALSE) getseisinfo(fnames, kind = 1)
fnames |
list of file names. |
kind |
an integer 1, 2, 3; 0=R(DAT) , 1 = segy, 2 = sac, 3 = AH. |
Iendian |
Endian-ness of the data: 1,2,3: "little", "big", "swap". Default = 1 (little) |
BIGLONG |
logical, TRUE=long=8 bytes |
HEADONLY |
logical, TRUE= header information only; not seismic trace will be returned (runs a little faster). |
PLOT |
logical, for if the traces should be plotted. This is interactive and can be shut off for large data sets. |
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.
See examples below for different cases.
List containing the seismic data and header information. Each trace consists of a list with:
fn |
original file name |
sta |
station name |
comp |
compnent |
dt |
delta t in seconds |
DATTIM |
time list |
yr |
year |
jd |
julian day |
mo |
month |
dom |
day of month |
hr |
hour |
mi |
minute |
sec |
sec |
msec |
milliseconds |
dt |
delta t in seconds |
t1 |
time start of trace |
t2 |
time end of trace |
off |
off-set |
N |
number of points in trace |
units |
units |
amp |
vector of trace values |
OLDER:
getseisinfo gets only the header information from the trace. Information in the file names is ignored, so be sure to modify headers prior to using this method of extracting meta-data. (Or modify the meta data from the file names after reading in the data.)
For SEGY files, in LINUX-UNIX, use: rename, segymod (PASSCAL) to modify the headers
JGET.seis extracts digital seismic data from binary files stored in the file system. The program uses readBin for I/O and passes data back to R. Currently SAC, SEGY formats are installed but it is easy to extend. AH format is available for LINUX systems, but there were problems compiling in WINDOWS and MACOS so this feature was removed. A filter for mseed format is currently being developed.
getseisinfo is an older (superceded) C-coded version to get the headers.
Jonathan M. Lees <jonathan.lees@unc.edu>
JSAC.seis , Mine.seis
## Not run: Lname = list.files(path='/data/wadati/bourbon/LaurelCanNC/R005.01' , pattern="08.005.01.41.23.9024", full.names=TRUE) S1 = JGET.seis(Lname, kind = 1, PLOT = FALSE) ### for data created on UNIX (SUN) but read on linux: S1 = JGET.seis(Lname, kind = 1, Iendian="swap", BIGLONG=FALSE, PLOT = FALSE) ### for data created on linux (32 bit) but read on linux 64 bit: S1 = JGET.seis(Lname, kind = 1, Iendian="little", BIGLONG=FALSE, PLOT = FALSE) ### for SEGY data created on linux (64 bit) but read on linux 32 bit: S1 = JGET.seis(Lname, kind = 1, Iendian="little", BIGLONG=TRUE, PLOT = FALSE) ### for SAC data created on MAC-OS (64 bit) but read on linux 32 bit: S1 = JGET.seis(Lname, kind = 2, Iendian="swap", BIGLONG=TRUE, PLOT = FALSE) ## End(Not run)