NAME¶
pswiggle - Plot anomaly along track on a map
SYNOPSIS¶
pswiggle xyz_files -Jparameters
-Rwest/east/south/north[
r]
-Zscale [
-A azimuth ] [
-Btickinfo ] [
-Ccenter ] [
-Dgap ] [
-Eazimuth/elevation ] [
-Gfillrgb ] [
-H[
nrec] ] [
-Ifix_az ] [
-K ] [
-M[
flag] ] [
-N ] [
-O ] [
-P ] [
-S[
x]
lon0/lat0/length[
units] ] [
-Ttrack_pen ] [
-U[
/dx/dy/][
label] ] [
-V ] [
-Wwiggle_pen ] [
-Xx-shift ] [
-Y y-shift ] [
-ccopies ] [
-: ] [
-bi[
s][
n] ]
DESCRIPTION¶
pswiggle reads (x,y,z) triplets from files [or standard input] and plots
z as a function of distance along track. This means that two consecutive (x,y)
points define the local distance axis, and the local z axis is then
perpendicular to the distance axis. The user may set a preferred positive
anomaly plot direction, and if the positive normal is outside the plus/minus
90 degree window around the preferred direction, then 180 degrees are added to
the direction. Either the positive or the negative wiggle may be shaded. The
resulting
PostScript code is written to standard output.
- files
- List one or more file-names. If no files are given, pswiggle will
read standard input.
- -J
- Selects the map projection. Scale is UNIT/degree, 1:xxxxx, or width in
UNIT (upper case modifier). UNIT is cm, inch, or m, depending on the
MEASURE_UNIT setting in .gmtdefaults, but this can be overridden on the
command line by appending the c, i, or m to the scale/width value.
CYLINDRICAL PROJECTIONS:
-Jclon0/lat0/scale (Cassini)
-Jjlon0/scale (Miller)
-Jmscale (Mercator - Greenwich and Equator as origin)
-Jmlon0/lat0/scale (Mercator - Give meridian and standard
parallel)
-Joalon0/lat0/azimuth/scale (Oblique Mercator - point and
azimuth)
-Joblon0/lat0/lon1/lat1/scale (Oblique Mercator - two points)
-Joclon0/lat0/lonp/latp/scale (Oblique Mercator - point and
pole)
-Jqlon0/scale (Equidistant Cylindrical Projection (Plate
Carree))
-Jtlon0/scale (TM - Transverse Mercator, with Equator as y =
0)
-Jtlon0/lat0/scale (TM - Transverse Mercator, set origin)
-Juzone/scale (UTM - Universal Transverse Mercator)
-Jylon0/lats/scale (Basic Cylindrical Projection)
AZIMUTHAL PROJECTIONS:
-Jalon0/lat0/scale (Lambert).
-Jelon0/lat0/scale (Equidistant).
-Jflon0/lat0/horizon/scale (Gnomonic).
-Jglon0/lat0/scale (Orthographic).
-Jslon0/lat0/[slat/]scale (General
Stereographic)
CONIC PROJECTIONS:
-Jblon0/lat0/lat1/lat2/scale (Albers)
-Jdlon0/lat0/lat1/lat2/scale (Equidistant)
-Jllon0/lat0/lat1/lat2/scale (Lambert)
MISCELLANEOUS PROJECTIONS:
-Jhlon0/scale (Hammer)
-Jilon0/scale (Sinusoidal)
-Jk[f|s]lon0/scale (Eckert IV (f) and VI (s))
-Jnlon0/scale (Robinson)
-Jrlon0/scale (Winkel Tripel)
-Jvlon0/scale (Van der Grinten)
-Jwlon0/scale (Mollweide)
NON-GEOGRAPHICAL PROJECTIONS:
-Jp[a]scale[/origin] (polar (theta,r)
coordinates, optional a for azimuths and offset theta [0])
-Jxx-scale[l|ppow][/y-scale[l|ppow]]
(Linear, log, and power scaling)
More details can be found in the psbasemap manpages.
- -R
- west, east, south, and north specify the Region of interest.
To specify boundaries in degrees and minutes [and seconds], use the
dd:mm[:ss] format. Append r if lower left and upper right map
coordinates are given instead of wesn.
- -Z
- Gives anomaly scale in data-units/distance-unit.
OPTIONS¶
No space between the option flag and the associated arguments.
- -A
- Sets the preferred positive azimuth. Positive wiggles will
"gravitate" towards that direction.
- -B
- Sets map boundary tickmark intervals. See psbasemap for
details.
- -C
- Subtract center from the data set before plotting [0].
- -D
- Means there is a data gap if 2 consecutive points are more than gap
distance units apart. For longitude/latitude data gap is in km,
else it is in the user's units.'
- -E
- Sets the viewpoint's azimuth and elevation [180/90]'
- -G
- Set fill of positive wiggles. [Default is black] Specify the shade (0-255)
or color (r/g/b, each in 0-255).
- -H
- Input file(s) has Header record(s). Number of header records can be
changed by editing your .gmtdefaults file. If used, GMT default is
1 header record.
- -I
- Set a fixed azimuth projection for wiggles [Default uses track azimuth,
but see -A].
- -K
- More PostScript code will be appended later [Default terminates the
plot system].
- -M
- Multiple segment file. Segments are separated by a record whose first
character is flag. [Default is '>'].
- -N
- Paint negative wiggles instead of positive [Default].
- -bo
- Selects binary output. Append s for single precision [Default is
double].
- -P
- Selects Portrait plotting mode [GMT Default is Landscape, see
gmtdefaults to change this].
- -S
- Draws a simple vertical scale centered on lon0/lat0. Use -Sx
to specify cartesian coordinates instead. length is in z units,
append unit name for labeling
- -T
- Draw track [Default is no track]. Append pen attributes to use [Defaults:
width = 1, color = 0/0/0, texture = solid].
- -U
- Draw Unix System time stamp on plot. User may specify where the lower left
corner of the stamp should fall on the page relative to lower left corner
of plot. Optionally, append a label, or c (which will plot the
command string.). The GMT parameters UNIX_TIME and UNIX_TIME_POS can
affect the appearance; see the gmtdefaults man page for
details.
- -V
- Selects verbose mode, which will send progress reports to stderr [Default
runs "silently"].
- -W
- Draw wiggle outline [Default is no outline]. Append pen attributes to use
[Defaults: width = 1, color = 0/0/0, texture = solid].
- -X -Y
- Shift origin of plot by (x-shift,y-shift). Prepend a for
absolute coordinates; the default ( r) will reset plot origin.
- -:
- Toggles between (longitude,latitude) and (latitude,longitude)
input/output. [Default is (longitude,latitude)]. Applies to geographic
coordinates only.
- -c
- Specifies the number of plot copies. [Default is 1]
- -bi
- Selects binary input. Append s for single precision [Default is
double]. Append n for the number of columns in the binary file(s).
[Default is 3 input columns].
EXAMPLES¶
To plot the magnetic anomaly stored in the file track.xym along track @ 1000
nTesla/cm (after removing a mean value of 32000 Tesla), using a 15 -cm-wide
Polar Stereographic map ticked every 5 degrees in Portrait mode, with positive
anomalies in red on a blue track of width 0.25 points, try
pswiggle track.xym
-R-20/10/-80/-60
-JS0/90/15
c
-Z1000
-B5
-P -G255/0/0
-T0.25
p/0/0/255
-S1000
-V > track_xym.ps
BUGS¶
Sometimes the (x,y) coordinates are not printed with enough significant digits,
so the local perpendicular to the track swings around a lot. To see if this is
the problem, you should do this:
awk '{ if (NR > 1) print atan2(y-$1, x-$2); y=$1; x=$2; }' yourdata.xyz |
more
(note that output is in radians; on some machines you need "nawk" to
do this). Then if these numbers jump around a lot, you may do this:
gmtset D_FORMAT %.12lg
awk '{ print NR, $0 }' yourdata.xyz | filter1d
-Fb5
-N4/0 >
smoothed.xyz
and plot this data set instead.
SEE ALSO¶
gmt(1gmt),
filter1d(1gmt),
psbasemap(1gmt),
splitxyz(1gmt)