1PSWIGGLE(1) GMT PSWIGGLE(1)
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6 pswiggle - Plot z = f(x,y) anomalies along tracks
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9 pswiggle [ table ] -Jparameters
10 -Rwest/east/south/north[/zmin/zmax][+r] -Zscale[units] [
11 |-A|[*azimuth] ] [ -B[p|s]parameters ] [ -Ccenter ] [ -G[+|-|=]fill
12 ] [ -Ifix_az ] [ -K ] [ -O ] [ -P ] [ -S[x]lon0/lat0/length[/units]
13 ] [ -Tpen ] [ -U[stamp] ] [ -V[level] ] [ -Wpen ] [ -Xx_offset ] [
14 -Yy_offset ] [ -bibinary ] [ -dinodata ] [ -eregexp ] [ -fflags ] [
15 -ggaps ] [ -hheaders ] [ -iflags ] [ -pflags ] [ -ttransp ] [ -:[i|o] ]
16 Note: No space is allowed between the option flag and the associated
18 arguments.
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21 pswiggle reads (x,y,z) triplets from files [or standard input] and
22 plots z as a function of distance along track. This means that two con‐
23 secutive (x,y) points define the local distance axis, and the local z
24 axis is then perpendicular to the distance axis, forming a right-handed
25 coordinate system. The user may set a preferred positive anomaly plot
26 direction, and if the positive normal is outside the plus/minus 90
27 degree window around the preferred direction, then 180 degrees are
28 added to the direction. Either the positive or the negative wiggle may
29 be shaded. The resulting PostScript code is written to standard output.
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32 -Jparameters (more ...)
33 Select map projection.
34 -Rxmin/xmax/ymin/ymax[+r][+uunit] (more ...)
36 Specify the region of interest.
37 For perspective view p, optionally append /zmin/zmax. (more ...)
39 -Zscale[units]
41 Gives anomaly scale in data-units/distance-unit, where dis‐
42 tance-unit is the currently chosen unit specified by
43 PROJ_LENGTH_UNIT. Alternatively, append a distance-unit among
44 the other choices (c|i|p).
45
47 table One or more ASCII (or binary, see -bi[ncols][type]) data table
48 file(s) holding a number of data columns. If no tables are given
49 then we read from standard input.
50 -A[azimuth]
52 Sets the preferred positive azimuth. Positive wiggles will
53 "gravitate" towards that direction, i.e., azimuths of the normal
54 direction to the track will be flipped into the -90/+90 degree
55 window centered on azimuth and that defines the positive wiggle
56 side. If no azimuth is given the no preferred azimuth is
57 enforced. Default is -A0.
58 -B[p|s]parameters (more ...)
60 Set map boundary frame and axes attributes.
61 -Ccenter
63 Subtract center from the data set before plotting [0].
64 -G[+|-|=]fill
66 Set fill shade, color or pattern for positive and/or negative
67 wiggles [Default is no fill]. Optionally, prepend + to fill pos‐
68 itive areas (this is the default behavior). Prepend - to fill
69 negative areas. Prepend = to fill both positive and negative
70 areas with the same fill.
71 -Ifix_az
73 Set a fixed azimuth projection for wiggles [Default uses track
74 azimuth, but see -A]. With this option, the calculated
75 track-normal azimuths are overridden by fixed_az.
76 -Jz|Zparameters (more ...)
78 Set z-axis scaling; same syntax as -Jx.
79 -K (more ...)
81 Do not finalize the PostScript plot.
82 -O (more ...)
84 Append to existing PostScript plot.
85 -P (more ...)
87 Select "Portrait" plot orientation.
88 -S[x]lon0/lat0/length[/units]
90 Draws a simple vertical scale centered on lon0/lat0. Use -Sx to
91 specify cartesian coordinates instead. length is in z units,
92 append unit name for labeling. FONT_ANNOT_PRIMARY is used as
93 font.
94 -Tpen Draw track [Default is no track]. Append pen attributes to use
96 [Defaults: width = 0.25p, color = black, style = solid].
97 -U[[just]/dx/dy/][c|label] (more ...)
99 Draw GMT time stamp logo on plot.
100 -V[level] (more ...)
102 Select verbosity level [c].
103 -Wpen
105 -bi[ncols][t] (more ...)
107 Select native binary input. [Default is 3 input columns].
108 -dinodata (more ...)
110 Replace input columns that equal nodata with NaN.
111 -e[~]"pattern" | -e[~]/regexp/[i] (more ...)
113 Only accept data records that match the given pattern.
114 -f[i|o]colinfo (more ...)
116 Specify data types of input and/or output columns.
117 -g[a]x|y|d|X|Y|D|[col]z[+|-]gap[u] (more ...)
119 Determine data gaps and line breaks.
120 -h[i|o][n][+c][+d][+rremark][+rtitle] (more ...)
122 Skip or produce header record(s).
123 -icols[+l][+sscale][+ooffset][,...] (more ...)
125 Select input columns and transformations (0 is first column).
126 -p[x|y|z]azim[/elev[/zlevel]][+wlon0/lat0[/z0]][+vx0/y0] (more ...)
128 Select perspective view.
129 -t[transp] (more ...)
131 Set PDF transparency level in percent.
132 -:[i|o] (more ...)
134 Swap 1st and 2nd column on input and/or output.
135 -^ or just -
137 Print a short message about the syntax of the command, then
138 exits (NOTE: on Windows just use -).
139 -+ or just +
141 Print an extensive usage (help) message, including the explana‐
142 tion of any module-specific option (but not the GMT common
143 options), then exits.
144 -? or no arguments
146 Print a complete usage (help) message, including the explanation
147 of all options, then exits.
148
150 To plot the magnetic anomaly stored in the file track.xym along track @
151 1000 nTesla/cm (after removing a mean value of 32000 nTesla), using a
152 15-cm-wide Polar Stereographic map ticked every 5 degrees in Portrait
153 mode, with positive anomalies in red on a blue track of width 0.25
154 points, use
155 gmt pswiggle track.xym -R-20/10/-80/-60 -JS0/90/15c -Z1000 -B5 \
157 -C32000 -P -Gred -T0.25p,blue -S1000 -V > track_xym.ps
158 and the positive anomalies will in general point in the north direc‐
160 tion. To instead enforce a fixed azimuth of 45 for the positive wig‐
161 gles, we add -I and obtain
162 gmt pswiggle track.xym -R-20/10/-80/-60 -JS0/90/15c -Z1000 -B5 \
164 -C32000 -P -Gred -I45 -T0.25p,blue -S1000 -V > track_xym.ps
165
167 Sometimes the (x,y) coordinates are not printed with enough significant
168 digits, so the local perpendicular to the track swings around a lot. To
169 see if this is the problem, you should do this:
170 awk '{ if (NR > 1) print atan2(y-$1, x-$2); y=$1; x=$2; }' yourdata.xyz | more
172 (note that output is in radians; on some machines you need "nawk" to do
174 this). Then if these numbers jump around a lot, you may do this:
175 awk '{ print NR, $0 }' yourdata.xyz | filter1d -Fb5 -N4/0 \
177 --FORMAT_FLOAT_OUT=%.12g > smoothed.xyz
178 which performs a 5-point boxcar filter, and plot this data set instead.
180
182 gmt, gmtcolors, filter1d, psbasemap, splitxyz
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185 2019, P. Wessel, W. H. F. Smith, R. Scharroo, J. Luis, and F. Wobbe
1865.4.5 Feb 24, 2019 PSWIGGLE(1)