NAME

       pswiggle - Plot z = f(x,y) anomalies along tracks

SYNOPSIS

       pswiggle  [ table ] parameters west/east/south/north[/zmin/zmax][r] scale [ azimuth ] [ [p|s]parameters ]
       [ center ] [ [+|-|=]fill ] [ z|Zparameters ] [ fix_az ] [  ] [  ] [ -P ] [ [x]lon0/lat0/length[/units]  ]
       [  pen  ]  [  [just/dx/dy/][c|label]  ]  [  [level] ] [ pen ] [ x_offset ] [ y_offset ] [ -bi<binary> ] [
       -ccopies ] [ -di<nodata> ] [ -f<flags> ] [ -g<gaps> ] [ -h<headers> ] [  -i<flags>  ]  [  -p<flags>  ]  [
       -t<transp> ] [ -:[i|o] ]

       Note: No space is allowed between the option flag and the associated arguments.

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.

REQUIRED ARGUMENTS

       -Jparameters (more ...)
              Select map projection.

       -R[unit]xmin/xmax/ymin/ymax[r] (more ...)
              Specify the region of interest.

       For perspective view p, optionally append /zmin/zmax. (more ...)

       -Zscale
              Gives anomaly scale in data-units/distance-unit.

OPTIONAL ARGUMENTS

       table  One or more ASCII (or binary, see -bi[ncols][type]) data table file(s) holding a  number  of  data
              columns. If no tables are given then we read from standard input.

       -Aazimuth
              Sets the preferred positive azimuth. Positive wiggles will "gravitate" towards that direction.

       -B[p|s]parameters (more ...)
              Set map boundary intervals.

       -Ccenter
              Subtract center from the data set before plotting [0].

       -G[+|-|=]fill
              Set  fill  shade,  color  or  pattern  for  positive and/or negative wiggles [Default is no fill].
              Optionally, prepend + to fill positive areas (this is the default behavior).  Prepend  -  to  fill
              negative areas. Prepend = to fill both positive and negative areas with the same fill.

       -Ifix_az
              Set a fixed azimuth projection for wiggles [Default uses track azimuth, but see -A].

       -Jz|Zparameters (more ...)
              Set z-axis scaling; same syntax as -Jx.

       -K (more ...)
              Do not finalize the PostScript plot.

       -O (more ...)
              Append to existing PostScript plot.

       -P (more ...)
              Select "Portrait" plot orientation.

       -S[x]lon0/lat0/length[/units]
              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. FONT_ANNOT_PRIMARY is used as font.

       -Tpen  Draw track [Default is no track]. Append pen attributes to use [Defaults: width = 0.25p,  color  =
              black, style = solid].

       -U[just/dx/dy/][c|label] (more ...)
              Draw GMT time stamp logo on plot.

       -V[level] (more ...)
              Select verbosity level [c].

       -Wpen

       -bi[ncols][t] (more ...)
              Select native binary input. [Default is 3 input columns].

       -ccopies (more ...)
              Specify number of plot copies [Default is 1].

       -dinodata (more ...)
              Replace input columns that equal nodata with NaN.

       -f[i|o]colinfo (more ...)
              Specify data types of input and/or output columns.

       -g[a]x|y|d|X|Y|D|[col]z[+|-]gap[u] (more ...)
              Determine data gaps and line breaks.

       -h[i|o][n][+c][+d][+rremark][+rtitle] (more ...)
              Skip or produce header record(s).

       -icols[l][sscale][ooffset][,...] (more ...)
              Select input columns (0 is first column).

       -p[x|y|z]azim/elev[/zlevel][+wlon0/lat0[/z0]][+vx0/y0] (more ...)
              Select perspective view.

       -t[transp] (more ...)
              Set PDF transparency level in percent.

       -:[i|o] (more ...)
              Swap 1st and 2nd column on input and/or output.

       -^ or just -
              Print a short message about the syntax of the command, then exits (NOTE: on Windows use just -).

       -+ or just +
              Print  an  extensive usage (help) message, including the explanation of any module-specific option
              (but not the GMT common options), then exits.

       -? or no arguments
              Print a complete usage (help) message, including the explanation of options, then exits.

       --version
              Print GMT version and exit.

       --show-datadir
              Print full path to GMT share directory and exit.

EXAMPLES

       To plot the magnetic anomaly stored in the file track.xym along track @ 1000 nTesla/cm (after removing  a
       mean  value  of  32000  nTesla),  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

              gmt pswiggle track.xym -R-20/10/-80/-60 -JS0/90/15c -Z1000 -B5 \
                           -C32000 -P -Gred -T0.25p,blue -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:

              awk '{ print NR, $0 }' yourdata.xyz | filter1d -Fb5 -N4/0 \
              --FORMAT_FLOAT_OUT=%.12g > smoothed.xyz

       and plot this data set instead.

SEE ALSO

       gmt, gmtcolors, filter1d, psbasemap, splitxyz

COPYRIGHT

       2015, P. Wessel, W. H. F. Smith, R. Scharroo, J. Luis, and F. Wobbe

5.2.1                                           January 28, 2016                                  PSWIGGLE(1gmt)