.. index:: ! pswiggle
.. include:: module_core_purpose.rst_

********
pswiggle
********

|pswiggle_purpose|

Synopsis
--------

.. include:: common_SYN_OPTs.rst_

**gmt pswiggle** [ *table* ] |-J|\ *parameters* |SYN_OPT-Rz| |-Z|\ *scale*
[ |-A|\ [*azimuth*] ]
[ |SYN_OPT-B| ]
[ |-C|\ *center* ]
[ |-D|\ *refpoint* ]
[ |-F|\ *panel* ]
[ |-G|\ *fill*\ [**+n**][**+p**] ]
[ |-I|\ *fix_az* ]
[ |-K| ]
[ |-O| ] [ |-P| ]
[ |-T|\ *pen* ]
[ |SYN_OPT-U| ]
[ |SYN_OPT-V| ]
[ |-W|\ *pen* ]
[ |SYN_OPT-X| ]
[ |SYN_OPT-Y| ]
[ |SYN_OPT-bi| ]
[ |SYN_OPT-di| ]
[ |SYN_OPT-e| ]
[ |SYN_OPT-f| ]
[ |SYN_OPT-g| ]
[ |SYN_OPT-h| ]
[ |SYN_OPT-i| ]
[ |SYN_OPT-p| ]
[ |SYN_OPT-qi| ]
[ |SYN_OPT-t| ]
[ |SYN_OPT-w| ]
[ |SYN_OPT-:| ]
[ |SYN_OPT--| ]

.. include:: wiggle.rst
    :start-after: .. module_common_begins
    :end-before: .. module_common_ends

.. include:: common_classic.rst_

Examples
--------

.. include:: explain_example.rst_

To demonstrate a basic wiggle plot we create some synthetic data with
:doc:`gmtmath` and pipe it through **pswiggle**::

    gmt math -T-8/6/0.01 -N3/0 -C2 T 3 DIV 2 POW NEG EXP T PI 2 MUL MUL COS MUL 50 MUL = | gmt pswiggle -R-10/10/-3/3 -JM6i -Baf -Z100i -DjRM+w100+lnT -Tfaint -Gred+p -W1p -BWSne -P > map.ps

To plot the magnetic anomaly stored in the file track.xym along track @
500 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 -Z500 -B5 \
                 -C32000 -P -Gred -T0.25p,blue -DjRM+w1000+lnT -V > track_xym.ps

and the positive anomalies will in general point in the north direction.
We used |-D| to place a vertical scale bar indicating a 1000 nT anomaly.
To instead enforce a fixed azimuth of 45 for the positive wiggles, we add |-I|
and obtain

   ::

    gmt pswiggle track.xym -R-20/10/-80/-60 -JS0/90/15c -Z1000 -B5 \
              -C32000 -P -Gred -I45 -T0.25p,blue -DjRM+w1000+lnT -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:

   ::

    gmt mapproject -Af yourdata.xyz | more

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

which performs a 5-point boxcar filter, and plot this data set instead.

See Also
--------

:doc:`gmt`, :doc:`gmtcolors`,
:doc:`filter1d`,
:doc:`psbasemap`,
:doc:`gmtsplit`