NAME
pswiggle - Plot anomaly along track on a map
SYNOPSIS
pswiggle xyz_files -Jparameters -Rwest/east/south/north[r] -Zscale [
-Aazimuth ] [ -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 ] [ -Yy-shift
] [ -ccopies ] [ -: ] [ -bi[s][n] ] [ -f[i|o]colinfo ]
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 con-
secutive (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 direc-
tion, 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 .gmtdefaults4, but this
can be overridden on the command line by appending c, i, or m to
the scale/width value. For map height, max dimension, or min
dimension, append h, +, or - to the width, respectively.
CYLINDRICAL PROJECTIONS:
-Jclon0/lat0/scale (Cassini)
-Jjlon0/scale (Miller)
-Jmscale (Mercator - Greenwich and Equator as origin)
-Jmlon0/lat0/scale (Mercator - Give meridian and standard paral-
lel)
-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 Car-
ree))
-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]][d] (Linear, log, and power
scaling)
More details can be found in the psbasemap man pages.
-R xmin, xmax, ymin, and ymax specify the Region of interest. For
geographic regions, these limits correspond to west, east,
south, and north and you may specify them in decimal degrees or
in [+-]dd:mm[:ss.xxx][W|E|S|N] format. Append r if lower left
and upper right map coordinates are given instead of wesn. The
two shorthands -Rg -Rd stand for global domain (0/360 or
-180/+180 in longitude respectively, with -90/+90 in latitude).
For calendar time coordinates you may either give relative time
(relative to the selected TIME_EPOCH and in the selected
TIME_UNIT; append t to -JX|x), or absolute time of the form
[date]T[clock] (append T to -JX|x). At least one of date and
clock must be present; the T is always required. The date string
must be of the form [-]yyyy[-mm[-dd]] (Gregorian calendar) or
yyyy[-Www[-d]] (ISO week calendar), while the clock string must
be of the form hh:mm:ss[.xxx]. The use of delimiters and their
type and positions must be as indicated (however, input/output
and plotting formats are flexible).
-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 annotation and tickmark intervals; see the
psbasemap man page for all the 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/s/v, with h in
0-360, s, and v in 0-1, and set COLOR_MODEL = hsv, or c/m/y/k,
each in 0-100 %). Alternatively, specify -Gpdpi/pattern, where
pattern gives the number of the built-in pattern (1-90) or the
name of a Sun 1-, 8-, or 24-bit raster file. The dpi sets the
resolution of the image. For 1-bit rasters: use -GP for inverse
video, or append :Fr/g/b[B[r/g/b]] to specify fore- and
background colors (use r/g/b = - for transparency). See GMT
Cookbook & Technical Reference Appendix E for information on
individual patterns.
-H Input file(s) has Header record(s). Number of header records can
be changed by editing your .gmtdefaults4 file. If used, GMT
default is 1 header record. Use -Hi if only input data should
have header records [Default will write out header records if
the input data have them].
-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].
-O Selects Overlay plot mode [Default initializes a new plot sys-
tem].
-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 abso-
lute coordinates; the default (r) will reset plot origin. Give
c to center plot using current page size.
-: Toggles between (longitude,latitude) and (latitude,longitude)
input and/or output. [Default is (longitude,latitude)]. Append
i to select input only or o to select output only. [Default
affects both].
-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].
-c Specifies the number of plot copies. [Default is 1].
-f Special formatting of input and output columns (time or geo-
graphical data) Specify i(nput) or o(utput) [Default is both
input and output]. Give one or more columns (or column ranges)
separated by commas. Append T (Absolute calendar time), t (time
relative to chosen TIME_EPOCH), x (longitude), y (latitude), g
(geographic coordinate), or f (floating point) to each column or
column range item.
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, use
pswiggle track.xym -R-20/10/-80/-60 -JS0/90/15c -Z1000 -B5 -P -G255/0/0
-T0.25p/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(l), filter1d(l), psbasemap(l), splitxyz(l)
GMT4.0 1 Oct 2004 PSWIGGLE(l)
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