.. index:: ! plot
.. include:: module_core_purpose.rst_

****
plot
****

|plot_purpose|

Synopsis
--------

.. include:: common_SYN_OPTs.rst_

**gmt plot** [ *table* ] |-J|\ *parameters*
|SYN_OPT-Rz|
[ |-A|\ [**m**\|\ **p**\|\ **x**\|\ **y**\|\ **r**\|\ **t**] ]
[ |SYN_OPT-B| ]
[ |-C|\ *cpt* ]
[ |-D|\ *dx*\ [/*dy*] ]
[ |-E|\ [**x**\|\ **y**\|\ **X**\|\ **Y**][**+a**\|\ **A**][**+cl**\|\ **f**][**+n**][**+w**\ *width*\ [/*cap*]][**+p**\ *pen*] ]
[ |-F|\ [**c**\|\ **n**\|\ **p**][**a**\|\ **s**\|\ **t**\|\ **r**\|\ *refpoint*] ]
[ |-G|\ *fill*\|\ **+z** ]
[ |-H|\ [*scale*] ]
[ |-I|\ [*intens*] ]
[ |-L|\ [**+b**\|\ **d**\|\ **D**][**+xl**\|\ **r**\|\ *x0*][**+yb**\|\ **t**\|\ *y0*][**+p**\ *pen*] ]
[ |-M|\ [**c**\|\ **s**][**+l**\ *seclabel*][**+g**\ *fill*][**+p**\ *pen*][**+r**\ *pen*][**+y**\ [*level*]] ]
[ |-N|\ [**c**\|\ **r**] ]
[ |-S|\ [*symbol*][*size*] ]
[ |SYN_OPT-U| ]
[ |SYN_OPT-V| ]
[ |-W|\ [*pen*][*attr*] ]
[ |SYN_OPT-X| ]
[ |SYN_OPT-Y| ]
[ |-Z|\ *value*\|\ *file*]\ [**+t**\|\ **T**] ]
[ |SYN_OPT-a| ]
[ |SYN_OPT-bi| ]
[ |SYN_OPT-di| ]
[ |SYN_OPT-e| ]
[ |SYN_OPT-f| ]
[ |SYN_OPT-g| ]
[ |SYN_OPT-h| ]
[ |SYN_OPT-i| ]
[ |SYN_OPT-l| ]
[ |SYN_OPT-p| ]
[ |SYN_OPT-qi| ]
[ |SYN_OPT-tv| ]
[ |SYN_OPT-w| ]
[ |SYN_OPT-:| ]
[ |SYN_OPT--| ]

.. module_common_begins

Description
-----------

Reads (*x*,\ *y*) pairs from *files* [or standard input] and will plot lines, polygons, or symbols at those locations on a map.
If a symbol is selected and no symbol size given, then it will interpret the third column of the input data as symbol size.
Symbols whose *size* is <= 0 are skipped. If no symbols are specified then the symbol code (see |-S| below) must be present as
last column in the input. If |-S| is not used, a line connecting the data points will be drawn instead. To explicitly close
polygons, use |-L|. Select a fill with |-G|. If |-G| is set, |-W| will control whether the polygon outline is drawn or not.
If a symbol is selected, |-G| and |-W| determine the fill and outline/no outline, respectively.

Required Arguments
------------------

.. |Add_intables| unicode:: 0x20 .. just an invisible code
.. include:: explain_intables.rst_

.. |Add_-J| replace:: |Add_-J_links|
.. include:: explain_-J.rst_
    :start-after: **Syntax**
    :end-before: **Description**

.. |Add_-R| replace:: |Add_-R_auto_table|
.. include:: explain_-R.rst_
    :start-after: **Syntax**
    :end-before: **Description**

.. |Add_-Rz| unicode:: 0x20 .. just an invisible code
.. include:: explain_-Rz.rst_

Optional Arguments
------------------

.. _-A:

.. include:: explain_line_draw.rst_

.. |Add_-B| replace:: |Add_-B_links|
.. include:: explain_-B.rst_
    :start-after: **Syntax**
    :end-before: **Description**

.. _-C:

**-C**\ *cpt*
    Give a CPT or specify **-C**\ *color1,color2*\ [*,color3*\ ,...]
    to build a linear continuous CPT from those colors automatically,
    where *z* starts at 0 and is incremented by one for each color.
    In this case *color*\ **n** can be a r/g/b triplet, a color name,
    or an HTML hexadecimal color (e.g. #aabbcc ).
    If |-S| is set, let symbol fill color be
    determined by the *z*-value in the third column. Additional fields are
    shifted over by one column (optional *size* would be 4th rather than 3rd
    field, etc.).
    If |-S| is not set, then it expects the user to
    supply a multisegment file where each segment header contains a
    **-Z**\ *value* string. The *value* will control the color of the line or
    polygon (if |-L| is set) via the CPT.  Alternatively, see the |-Z|
    option for how to assign *z*-values. **Note**: If modern mode and no
    argument is given then we select the current CPT.

.. _-D:

**-D**\ *dx*\ [/*dy*]
    Offset the plot symbol or line locations by the given amounts
    [Default is no offset]. If *dy* is not given it is set equal to *dx*.
    You may append dimensional units from **c**\ \|\ **i**\ \|\ **p** to each value.

.. _-E:

**-E**\ [**x**\|\ **y**\|\ **X**\|\ **Y**][**+a**\|\ **A**][**+cl**\|\ **f**][**+n**][**+w**\ *width*\ [/*cap*]][**+p**\ *pen*]
    Draw error bars or box-and-whisker symbols. Make the selection via a directive
    (if no directive is given we plot both the *x* and *y* error bars, i.e., |-E|\ **xy**):

    - **x** - Draw an error bar in *x* direction. The *x* errors must be stored
      in the columns after the (*x, y*) pair [or (*x, y, z*) triplet].
    - **y** - Draw an error bar in *y* direction. The *y* errors must be stored
      in the columns after the (*x, y*) pair [or (*x, y, z*) triplet].
    - **X** - Draw a box-and-whisker symbol (i.e., stem-and-leaf) in *x* direction.
      The *x* coordinate is then taken as the median value, and four more columns
      are expected to contain the minimum (0% quantile), the 25% quantile, the 75% quantile,
      and the maximum (100% quantile) *x*-values. The 25-75% box may be filled by
      using |-G|. These quantities must be stored in the columns after the (*x, y*)
      pair [or (*x, y, z*) triplet].
    - **Y** - Draw a box-and-whisker symbol (i.e., stem-and-leaf) in *y* direction.
      Same layount as for **X**.

    Several modifiers can affect the appearance of the symbols:

    - **+a** - Draw asymmetrical error bars [Default is symmetrical error bars];
      these requires two rather than one extra data column, with the two signed
      deviations.
    - **+A** - Similar, but read the low and high bounds rather than signed deviations.
    - **+n** - Draw notched "box-and-whisker" symbols where the notch width reflects
      the uncertainty in the median. This symbol requires a 5th extra data column to
      contain the number of points in the distribution.
    - **+w** - Set the *width* that indicates the length of the end-cap on error bars [7\ **p**].
      For box-and-whisker symbols it sets both the default box width *and* whisker cap length [7\ **p**].
      Append *width*\ /*cap* to set separate width and cap dimensions for such symbols.
    - **+p** - Append preferred error bar *pen* [Defaults: width = 0.25p, color = black, style = solid].
    - **+c** - When |-C| is used we can control how the look-up color is applied to our symbol.
      Append **+cf** to use it to fill the symbol, while **+cl** will just
      set the error pen color and turn off symbol fill.  Giving **+c** without an argument
      will set both color items.

    **Note**: The error bars are placed behind symbols except for the large vertical and
    horizontal bar symbols (**-Sb**\|\ **B**) where they are plotted on top to avoid the
    lower bounds being obscured.

.. _-F:

**-F**\ [**c**\|\ **n**\|\ **p**][**a**\|\ **r**\|\ **s**\|\ **t**\|\ *refpoint*]
    Alter the way points are connected (by specifying a *scheme*) and data are grouped (by specifying a *method*).
    Append one of three line connection schemes:

    - **c**\ : Form continuous line segments for each group [Default].
    - **n**\ : Form networks of line segments between all points in each group.
    - **p**\ : Form line segments from a reference point reset for each group.

    Optionally, append the one of four segmentation methods to define the group:

    - **a**\ : Ignore all segment headers, i.e., let all points belong to a single group,
      and set group reference point to the very first point of the first file.
    - **r**\ : Segment headers are honored so each segment is a group; the group
      reference point is reset after each record to the previous point (this method
      is only available with the **-Fp** scheme).
    - **s**\ : Same as **r**, but the group reference point is reset to the first
      point of each incoming segment [Default].
    - **t**\ : Consider all data in each table to be a single separate group and
      reset the group reference point to the first point of each group.

    Instead of the codes **a**\|\ **r**\|\ **s**\|\ **t** you may append the
    *lon/lat* (or *x/y*) coordinates of a *refpoint*, which will serve as a fixed
    external reference point for all groups.

    .. figure:: /_images/GMT_segmentize.*
        :width: 600 px
        :align: center

        Use the |-F| option to create various networks between input point.  Dashed lines
        indicate input ordering for the two tables, while solid lines are the resulting
        network connections. Top left is original input, while the next five reflect the results
        of directives **pa**, **pt**, **ps**, **p**\ 10/35 and **na**.

.. _-G:

**-G**\ *fill*\|\ **+z** :ref:`(more ...) <-Gfill_attrib>`
    Select color or pattern for filling of symbols or polygons [Default is no fill].
    Note that this module will search for |-G| and |-W| strings in all the
    segment headers and let any values thus found over-ride the command line settings.
    If |-Z| is set, use **-G+z** to assign fill color via **-C**\ *cpt* and the
    *z*-values obtained (same if transparency is set via |-Z|). Finally, if
    *fill* = *auto*\ [*-segment*] or *auto-table* then
    we will cycle through the fill colors implied by :term:`COLOR_SET` and change on a per-segment
    or per-table basis.  Any *transparency* setting is unchanged.

.. _-H:

**-H**\ [*scale*]
    Scale symbol sizes and pen widths on a per-record basis using the *scale* read from the
    data set, given as the first column after the (optional) *z* and *size* columns [no scaling].
    The symbol size is either provided by |-S| or via the input *size* column.  Alternatively,
    append a constant *scale* that should be used instead of reading a scale column.

.. _-I:

**-I**\ *intens*
    Use the supplied *intens* value (nominally in the ±1 range) to
    modulate the fill color by simulating illumination [none]. If no intensity
    is provided we will instead read *intens* from the first data column after
    the symbol parameters (if given).

.. _-L:

**-L**\ [**+b**\|\ **d**\|\ **D**][**+xl**\|\ **r**\|\ *x0*][**+yb**\|\ **t**\|\ *y0*][**+p**\ *pen*] |ex_OPT-L|
    Force closed polygons.  Alternatively, append modifiers to build a polygon from a line segment:

    - **+d** - Build a symmetrical envelope around *y*\ (*x*) using deviations *dy*\ (*x*) given in extra column 3.
    - **+D** - Build an asymmetrical envelope around *y*\ (*x*) using deviations *dy1*\ (*x*) and *dy2*\ (*x)* from extra columns 3-4.
    - **+b** - Build an asymmetrical envelope around *y*\ (*x*) using bounds *yl*\ (*x*) and *yh*\ (*x*) from extra columns 3-4.
    - **+x** - Connect first and last point to anchor points at either *xmin* (append **l**), *xmax* (append **r**), or *x0* (append it).
    - **+y** - Connect first and last point to anchor points at either *ymin* (append **b**), *xmax* (append **t**), or *y0* (append it).

    Such polygons may be painted (|-G|) and optionally outlined by adding modifier **+p**\ *pen* [no outline].
    **Note**: When option |-Z| is passed via segment headers you will need |-L| to ensure
    your segments are interpreted as polygons, else they will be seen as lines.

.. _-M:

**-M**\ [**c**\|\ **s**][**+l**\ *seclabel*][**+g**\ *fill*][**p**\ *pen*][**+r**\ *pen*][**+y**\ [*level*]]
    Fill the middle area between two curves :math:`y_0(x)` and :math:`y_1(x)`, expected to be
    given via one or more pairs of separate tables, each pair of tables having the same
    number of segments (which can vary from pair to pair). Thus, the order of the even
    number of tables given on the command line is important. Two directives are available:

    - **c** - Indicate that :math:`y_1(x)` is co-registered with :math:`y_0(x)` and is given
      as column 2 (i.e., third) in any number of files having three columns. Each file may
      contain any number of segments per file.
    - **s** - Same but the two curves are given via separate pairs of tables [Default].
    
    Several modifiers are at your disposal:

    - **+g** - We use the *fill* set via |-G| to fill the areas where :math:`y_0(x)` exceeds
      :math:`y_1(x)`. For the opposite case, append another *fill* here.  
    - **+l** - For the primary curve :math:`y_0(x)`, a legend label can be set via option
      |SYN_OPT-l|. For a secondary label use this modifier to append the label.  
    - **+p** - Specify a separate pen for drawing curve :math:`y_1(x)` [Default is same pen
      as :math:`y_0(x)`]. See |-W| for specifying the pen for curve :math:`y_0(x)`.
    - **+r** - Specify a pen to simply draw a line instead of a filled box in the legend, but
      replace the color information with that from the fill settings (i.e., only the *pen*
      width is used as specified, the color is not used).
    - **+y** - Compare your data with a horizontal constant line then append the level and the
      :math:`y_1(x)` curve is generated for you and all input files will be compared with it.

    **Notes**: (1) Normally, we show one (|-G|) or two (**+g**) filled rectangles in the legend
    if fill was selected for the alternating areas between the two curves. (2) You must at least
    specify either one fill or one pen, depending on your desired result.

    .. figure:: /_images/GMT_fill_curves.*
        :width: 600 px
        :align: center

        Use the |-M| option to paint the area between curves. Intersections and NaN-gaps are
        found and the color depends on which curve is on top. Legends can be set as filled
        rectangles or lines with colors from the fill selections via **+r**.

.. _-N:

**-N**\ [**c**\|\ **r**]
    Do **not** clip symbols that fall outside map border [Default plots points
    whose coordinates are strictly inside the map border only]. For periodic (360-longitude)
    maps we must plot all symbols twice in case they are clipped by the repeating
    boundary. The |-N| will turn off clipping and not plot repeating symbols.
    Use **-Nr** to turn off clipping but retain the plotting of such repeating symbols, or
    use **-Nc** to retain clipping but turn off plotting of repeating symbols.
    **Note**: A plain |-N| may also be used with lines or polygons but note that this deactivates
    any consideration of periodicity (e.g., longitudes) and may have unintended consequences.

.. _-S:

.. include:: explain_symbols.rst_

.. |Add_-U| replace:: |Add_-U_links|
.. include:: explain_-U.rst_
    :start-after: **Syntax**
    :end-before: **Description**

.. |Add_-V| replace:: |Add_-V_links|
.. include:: explain_-V.rst_
    :start-after: **Syntax**
    :end-before: **Description**

.. _-W:

**-W**\ [*pen*][*attr*] :ref:`(more ...) <-Wpen_attrib>`
    Set pen attributes for lines or the outline of symbols [Defaults:
    *width* = 0.25p, *color* = black, *style* = solid]. Modifiers can be used to change the
    appearance of the line:

    - **+c** - Determine how the color from the cpt file lookup is applied to symbol 
      and|or fill.  Append **l** to have the color of the line to be taken from the CPT (see
      |-C|). If instead **f** is appended then the color from the cpt file is applied
      to symbol fill.  If no argument is given the we use the color for both pen and fill.
    - **+o** - Append *offset*\ [*unit*] and we will start and stop drawing the line at the
      given distance *offset* from the end point. Append a *unit* from **c**\|\ **i**\|\ **p** to
      indicate plot distance offsets on the map or append map distance units instead (see Units below)
      [Cartesian distances]. Give *offset* as *b_offset*/*e_offset* if the beginning and end of the
      line should have different offsets.
    - **+s** - Draw the line using a Bezier spline [linear spline].
    - **+v** - Given [**b**\|\ **e**]\ *vspecs*, we place a vector head at the ends of the lines. Prepend
      **b** (beginning) or **e** (end) to add a vector at only one end [Default is shared specs for both end of the line].
      **Note** - Because **+v** may take additional modifiers it must necessarily be given
      at the end of the pen specification. See the `Vector Attributes`_ for more information or such modifiers.
    - **+z** - If |-Z| is set, assign pen color via **-C**\ *cpt* and the *z*-values obtained
      (same if transparency is set via |-Z|).  Finally, if pen *color* = *auto*\ [*-segment*] or *auto-table* then
      we will cycle through the pen colors implied by :term:`COLOR_SET` and change on a per-segment
      or per-table basis.  The *width*, *style*, or *transparency* settings are unchanged.

.. |Add_-XY| replace:: |Add_-XY_links|
.. include:: explain_-XY.rst_
    :start-after: **Syntax**
    :end-before: **Description**

.. _-Z:

**-Z**\ *value*\|\ *file*\ [**+t**\|\ **T**]
    Control the color and|or transparency of line and polygons.
    Instead of specifying a line or polygon fill and outline color via |-G| and |-W|,
    pass a color lookup table via |-C|. Then, select one of two modes:

    1. Append a *value* and the color is looked-up via the CPT.
    2. Give the name of a *file* with one z-value (read from the last column) for each polygon
       or line in the input data.

    To apply the color we must use the |-G| or |-W| options in conjunction with |-Z|:

    - **-G+z** - Apply the color to the polygon fill.
    - **-W+z** - Apply the color to the pen instead.

    Two modifiers is used to also handle transparency and|or color:

    - **+t** - Modulate the transparency of the polygon or line instead; the
      *z*-value will be assumed to be transparency in the 0-100 % range.
    - **+T** - Supply two columns via *file*: The last column must be the *z*-value
      while the penultimate column must have transparencies (in 0-100 % range).

.. include:: explain_-aspatial.rst_

.. |Add_-bi| replace:: [Default is the required number of columns given the chosen settings].
.. include:: explain_-bi.rst_

.. |Add_-di| unicode:: 0x20 .. just an invisible code
.. include:: explain_-di.rst_

.. |Add_-e| unicode:: 0x20 .. just an invisible code
.. include:: explain_-e.rst_

.. |Add_-f| unicode:: 0x20 .. just an invisible code
.. include:: explain_-f.rst_

.. |Add_-g| replace:: The **-g** option is ignored if |-S| is set.
.. include:: explain_-g.rst_

.. |Add_-h| unicode:: 0x20 .. just an invisible code
.. include:: explain_-h.rst_

.. include:: explain_-icols.rst_

.. |Add_-l| unicode:: 0x20 .. just an invisible code
.. include:: explain_-l.rst_

.. include:: explain_-qi.rst_

.. include:: explain_colon.rst_

.. |Add_perspective| unicode:: 0x20 .. just an invisible code
.. include:: explain_perspective.rst_

.. include:: explain_-tv_full.rst_

.. include:: explain_-w.rst_

.. include:: explain_help.rst_

.. include:: explain_distunits.rst_

.. include:: explain_vectors.rst_

.. module_common_ends

Examples
--------

.. include:: explain_example.rst_

.. include:: oneliner_info.rst_

To plot solid red circles (diameter = 0.2 cm) at the positions listed
in the remote file DSDP.txt on a Mercator map at 0.3 cm/degree of the area 100E to
160E, 20S to 30N, with automatic tick-marks and gridlines::

    gmt plot @DSDP.txt -R100/160/-20/30 -Jm0.3c -Sc0.2c -Gred -Bafg -pdf map

To plot the xyz values in the file quakes.xyzm as circles with size
given by the magnitude in the 4th column and color based on the depth in
the third using the CPT rgb.cpt on a linear map::

    gmt plot quakes.xyzm -R0/1000/0/1000 -JX6i -Sc -Crgb -B200 -pdf map

To plot the file trench.txt on a Mercator map, with white triangles with
sides 0.25 inch on the left side of the line, spaced every 0.8 inch::

    gmt plot trench.txt -R150/200/20/50 -Jm0.15i -Sf0.8i/0.1i+l+t -Gwhite -W -B10 -pdf map

To plot a circle with color dictated by the *t.cpt* file for the *z*-value 65::

    echo 175 30 | gmt plot -R150/200/20/50 -JM15c -B -Sc0.5c -Z65 -Ct.cpt -G+z -pdf map

To plot the data in the file misc.txt as symbols determined by the code in
the last column, and with size given by the magnitude in the 4th column,
and color based on the third column via the CPT chrome on a
linear maps::

    gmt plot misc.txt -R0/100/-50/100 -JX6i -S -Cchrome -B20 -pdf map

If you need to place vectors on a plot you can choose among
straight Cartesian vectors, math circular vectors, or geo-vectors (these
form small or great circles on the Earth).  These can have optional heads at either
end, and heads may be the traditional arrow, a circle, or a terminal cross-line.
To place a few vectors with
a circle at the start location and an arrow head at the end::

    gmt plot -R0/50/-50/50 -JX6i -Sv0.15i+bc+ea -Gyellow -W0.5p -Baf -pdf map << EOF
    10 10 45 2i
    30 -20 0 1.5i
    EOF

To plot vectors (red vector heads, solid stem) from the file data.txt that contains
record of the form *lon, lat, dx, dy*, where *dx, dy* are the Cartesian
vector components given in user units, and these user units should be converted
to cm given the scale 3.60::

    gmt plot -R20/40/-20/0 -JM6i -Sv0.15i+e+z3.6c -Gred -W0.25p -Baf data.txt -pdf map

.. include:: plot_notes.rst_

.. include:: auto_legend_info.rst_

See Also
--------

:doc:`gmt`, :doc:`gmt.conf`,
:doc:`gmtcolors`,
:doc:`basemap`, :doc:`plot3d`

.. ------------------------------------- Examples per option -------------------

.. |ex_OPT-L| raw:: html

   <a href="#openModal">Example</a>
   <div id="openModal" class="modalDialog">
    <div>
        <a href="#close" title="Close" class="close">X</a>
        <h2>-L example</h2>
        <p>
        cat << EOF > t.txt</br>
        1 1</br>
        2 3</br>
        3 2</br>
        4 4</br>
        EOF</br>
        gmt begin filler pdf</br>
          gmt plot -R0/5/0/5 -JX3i -B t.txt -Gred -W2p -L+yb</br>
          gmt plot -B t.txt -Gred -W2p -L+yt -X3.25i</br>
          gmt plot -B t.txt -Gred -W2p -L+xl -X-3.25i -Y3.25i</br>
          gmt plot -B t.txt -Gred -W2p -L+xr -X3.25i</br>
          gmt plot -B t.txt -Gred -W2p -L+y4 -X-3.25i -Y3.25i</br>
          gmt plot -B t.txt -Gred -W2p -L+x4.5 -X3.25i</br>
        gmt end show</br>
        </p>
    </div>
   </div>
