SAC Command Reference Manual

Functional Command Listing

Executive Function: Information and Control

about:Displays version and copyright information
intro:Provides a brief introduction to SAC
help:Prints information about SAC commands and features.
printhelp:Command for printing help pages from within SAC
comcor:Controls SAC's command correction option.
inicm:Reinitializes all of SAC's common blocks.
production:Controls the production mode option.
report:Informs the user about the current state of SAC.
trace:Controls the tracing of blackboard and header variables.
echo:Controls echoing of commands to the terminal.
history:Provides easy access to previous commands (like unix history)
message:Sends a message to the user's terminal.
quit:Terminates SAC.
quitsub:Terminates the currently active subprocess.
pause:Sends a message to the terminal and pauses.
transcript:Controls output to the transcript file.

Executive Function: Processing and Macros

evaluate:Evaluates simple arithmetic expressions.
mathop:Select the sequencing order for inline functions
getbb:Gets (prints) values of blackboard variables.
setbb:Sets (defines) values of blackboard variables.
unsetbb:Unsets (deletes) blackboard variables.
installmacro:Installs macro files in the global SAC macro directory.
macro:Executes a SAC macro file.
setmacro:Defines directories to search when executing a SAC macro file.
systemcommand:Executes system commands from SAC.

Data File Module

read:Reads data from SAC data files on disk into memory.
write:Writes data in memory to disk.
readdb:Reads data from an Oracle database NO LONGER FUNCTIONAL
readcss:Reads CSS format data files into SAC.
writecss:Writes CSS format data files from SAC.
readgse:Reads GSE2.0 format data
writegse:Writes GSE2.0 format data
readsuds:Reads PC Suds data
readtable:Reads alphanumeric data files on disk into memory.
datagen:Generates sample data files and stores them in memory.
funcgen:Generates a function and stores it in memory.
convert:Converts data files from one format to another.
commit:Commits (copies) SAC's data to the I/O buffers
rollback:Replaces active data with data last committed to the I/O buffers
recalltrace:Rolls back waveforms and selected headers from I/O buffers and commits the rest of the headers.
readhdr:Reads headers from SAC data files into memory.
writehdr:Overwrites the headers on disk with those in memory.
listhdr:Lists the values of selected header fields.
chnhdr:Changes the values of selected header fields.
copyhdr:Copies header variables from one file in memory to all others.
readbbf:Reads a blackboard variable file into memory.
writebbf:Writes a blackboard variable file to disk.
cd:change the working directory within SAC
cut:Defines how much of a data file is to be read.
cuterr:Controls errors due to bad cut parameters.
cutim:Cuts data after its already been read into memory
deletechannel:Deletes selected channels from memory
pickauthor:Controls author name when reading picks.
pickphase:Controls phase names to load into the SAC headers.
readerr:Controls errors that occur during the read command.
synchronize:Synchronizes the reference times of all files in memory.
sort:Sorts waveforms based on selected header variables
wild:Sets wildcard characters used in read commands to expand

Graphics Environment Module

saveimg:Saves displayed graphics windows in a variety of formats.
xlim:Determines the plot limits for the x axis.
ylim:Determines the plot limits for the y axis.
linlin:Turns on linear scaling for the x and y axes.
linlog:Turns on linear scaling for x axis and logarithmic for y axis.
loglin:Turns on logarithmic scaling for x axis and linear for y axis.
loglog:Turns on logarithmic scaling for the x and y axes.
xlin:Turns on linear scaling for the x axis.
xlog:Turns on logarithimic scaling for the x axis.
ylin:Turns on linear scaling for the y axis.
ylog:Turns on logarithimic scaling for the y axis.
xdiv:Controls the x axis division spacing.
ydiv:Controls the y axis division spacing.
xfull:Controls plotting of x axis full logarithmic decades.
yfull:Controls plotting of y axis full logarithmic decades.
xfudge:Changes the x axis "fudge factor."
yfudge:Changes the y axis "fudge factor."
axes:Controls the location of annotated axes.
border:Controls the plotting of a border around plots.
grid:Controls the plotting of grid lines in plots.
xgrid:Controls plotting of grid lines in the x direction.
ygrid:Controls plotting of grid lines in the y direction.
ticks:Controls the location of tick marks on plots.
title:Defines the plot title and attributes.
xlabel:Defines the x axis label and attributes.
ylabel:Defines the y axis label and attributes.
plabel:Defines general plot labels and their attributes.
filenumber:Controls plotting of filenumbers next to each file.
fileid:Controls the file id display found on most SAC plots.
picks:Controls the display of time picks on most SAC plots.
gtext:Controls the quality and font of text used in plots.
tsize:Controls the text size attributes.
loglab:Controls labels on logarithmically scaled axes.
color:Controls color selection for color graphics devices.
line:Controls the linestyle selection in plots.
symbol:Controls the symbol plotting attributes.
qdp:Controls the "quick and dirty plot" option
width:Controls the width of data lines
beginframe:Turns off automatic new frame actions between plots.
endframe:Resumes automatic new frame actions between plots.
beginwindow:Begins plotting to a new graphics window.
window:Sets the location and shape of graphics windows.
xvport:Defines the viewport for the x axis.
yvport:Defines the viewport for the y axis.
floor:Puts a minimum value on logarithmically interpolated data.
null:Controls plotting of predefined null data values.

Graphics Control Module

setdevice:Defines a default graphics device to use in subsequent plots.
begindevices:Begins plotting to one or more graphics devices.
enddevices:Terminates one or more graphics devices.
vspace:Changes the maximum size and shape of plots.
sgf:Controls the SAC Graphics File device options.
pause:Tells SAC to pause for specified length of time.
wait:Tells SAC whether or not to pause between plots.
print:Print the most recent SGF file. Many plot commands also have a print option.

Graphics Action Module

plot:Generates a single-trace single-window plot.
PLOT1:Generates a multi-trace multi-window plot.
PLOT2:Generates a multi-trace single-window (overlay) plot.
plotpk:Produces a plot for the picking of arrival times.
plotpktable:Table describing PLOTPK options.
plotdy:Plots data with error bars
plotxy:Plots one or more data files versus another data file.
plotalpha:Reads data from Tables and plots with labels
plotc:Annotates SAC plots and creates figures using cursor.
plotctable:Table describing PLOTC options.
plotsp:Plots spectral data in several different formats.
plotpm:Generates a "particle-motion" plot of pairs of data files.
erase:Erases the graphics display area.

Spectral Analysis Module

fft:Performs a discrete Fourier transform.
keepam:Keep only the amplitude component of the spectral file.
ifft:Performs an inverse discrete Fourier transform.
plotsp:Plots spectral data in several different formats.
writesp:Writes spectral files to disk as "normal" data files.
readsp:Reads spectral files written by @writesp@.
lowpass:Applies an IIR lowpass filter.
highpass:Applies an IIR highpass filter.
bandpass:Applies an IIR bandpass filter.
bandrej:Applies an IIR bandreject filter.
wiener:Applies an adaptive Wiener filter.
fir:Applies a finite-impulse-response filter.
hanning:Applies a "hanning" window to each data file.
unwrap:Computes amplitude and unwrapped phase.
khronhite:Applies a Khronhite filter to the data.
benioff:Applies a Benioff filter to the data.
divomega:Performs integration in the frequency domain.
mulomega:Performs differentiation in the frequency domain.
hilbert:Applies a Hilbert transform.
convolve:Computes the convolution of waveforms.
correlate:Computes the auto- and cross- correlation functions.
envelope:Computes the envelope function using a Hilbert transform.

Unary Operations Module

add:Adds a constant to each data point.
sub:Subtracts a constant from each data point.
mul:Multiplies each data point by a constant.
div:Divides each data point by a constant.
sqr:Squares each data point.
sqrt:Takes the square root of each data point.
int:Performs integration using the trapezoidal rule.
abs:Takes the absolute value of each data point.
log:Takes the natural logarithm of each data point.
LOG10:Takes the base 10 logarithm of each data point.
exp:Computes the exponential of each data point.
EXP10:Computes the base 10 exponential (10.**y) of each data point.
dif:Differentiates data in memory.

Binary Operations Module

merge:Merges (concantenates) a set of files to data in memory.
addf:Adds a set of data files to data in memory.
subf:Subtracts a set of data files from data in memory.
mulf:Multiplies a set of files by the data in memory.
divf:Divides data in memory by a set of data files.
binoperr:Controls errors that can occur during binary file operations.

Signal Correction Module

rq:Removes the seismic Q factor from spectral data.
rglitches:Removes glitches and timing marks.
rtrend:Removes the linear trend.
rmean:Removes the mean.
taper:Applies a symmetric taper to each end of data.
rotate:Rotates a pair of data components through an angle.
interpolate:Interpolates evenly or unevenly spaced data to a new sampling rate.
quantize:Converts continuous data into its quantized equivalent.
stretch:Stretches (upsamples) data, including an optional interpolating FIR filter.
reverse:Reverse the order of data points.
smooth:Applies an arithmetic smoothing algorithm to the data.
decimate:Decimates (downsamples) data, including an optional anti-aliasing FIR filter.

Event Analysis Module

ohpf:Opens a HYPO formatted pick file.
chpf:Closes the currently open HYPO pick file.
whpf:Writes auxiliary cards into the @hypo@ pick file.
oapf:Opens a alphanumeric pick file.
capf:Closes the currently open alphanumeric pick file.
apk:Applies an automatic event picking algorithm.
plotpk:Produces a plot for the picking of arrival times.
plotpktable:Table describing PLOTPK options.
pickauthor:Controls author name when reading picks.
pickphase:Controls phase names to load into the SAC headers.

Signal Measurement Module

mtw:Determines the measurement time window for use in subsequent measurement commands.
markvalue:Searches for and marks values in a data file.
marktimes:Marks files with travel times from a velocity set.
markptp:Measures and marks the maximum peak to peak amplitude of each signal within the measurement time window.
rms:Computes the root mean square of the data within the measurement time window.

XYZ (3-D) Data Module

spectrogram:Calculates a spectrogram using all of the data in memory.
sonogram:Calculates a sonogram using all of the data in memory.
image:Plots 3D data files as color images
loadctable:Loads specified color table into memory
grayscale:Produces grayscale images of data in memory.
contour:Produces contour plots of data in memory.
zlevels:Controls the contour line spacing in subsequent contour plots.
zlines:Controls the contour linestyles in subsequent contour plots.
zticks:Controls the labeling of contour lines with directional tick marks.
zlabels:Controls the labeling of contour lines with alphanumeric labels.
zcolors:Controls the color display of contour lines.

Instrument Correction Module

transfer:Performs deconvolution to remove an instrument response and convolution to apply another instrument response.
transfertable:Details for instrument types in transfer

Subprocess Invoking Module

spe:Initializes the Spectral Estimation Subprocess. SPE Commands
sss:Initializes the Signal Stacking Subprocess. SSS Commands

Analysis Tools

3C:GUI based three component processing tool
convolve:Computes the convolution of waveforms.
correlate:Computes the auto- and cross- correlation functions.
envelope:Computes the envelope function using a Hilbert transform.
filterdesign:Graphicly display the filter's digital vs. analog characteristics.
linefit:Fits a line to data in memory and write results to blackboard
mat:Runs a MATLAB interactively or as a script on data in SAC
map:Uses GMT to create a MAP based on data in SAC
whiten:Whitens the data in memory

FK Spectrum

bbfk:Computes broadband frequency-wavenumber (FK) spectral estimate.
beam:Computes the beam.