gmt-fork/doc/rst/source/supplements/geodesy/velo_common.rst_

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

Reads data values from *files* [or standard input] and
will plot velocity arrows on a map.
Most options are the same as for :doc:`plot </plot>`, except **-S**.

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

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

.. _-J:

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

.. _-R:

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

.. _-S:

**-S**
    Selects the meaning of the columns in the data file and the figure to be plotted.  In all
    cases, the scales are in data units per length unit and sizes are in length units (default length
    unit is controlled by :term:`PROJ_LENGTH_UNIT` unless **c**, **i**, or **p** is appended).

    **-Se**\ *velscale/confidence*\ [**+f**\ *font*]

        Velocity ellipses in (N,E) convention. *velscale* sets the scaling of the
        velocity arrows. The *confidence* sets the 2-dimensional confidence
        limit for the ellipse, e.g., 0.95 for 95% confidence ellipse. *font*
        sets the font and size of the text [9p,Helvetica,black]. The ellipse will be filled with the
        color or shade specified by the |-G| option [default transparent]. The
        arrow and the circumference of the ellipse will be drawn with the pen
        attributes specified by the |-W| option. Parameters are expected to be
        in the following columns:

            **1**,\ **2**:
            longitude, latitude of station (**-:** option interchanges order)
            **3**,\ **4**:
            eastward, northward velocity (**-:** option interchanges order)
            **5**,\ **6**:
            uncertainty of eastward, northward velocities (1-sigma) (**-:** option interchanges order)
            **7**:
            correlation between eastward and northward components
            **8**:
            name of station (optional).

    **-Sn**\ *barscale*

        Anisotropy bars. *barscale* sets the scaling of the bars.
        Parameters are expected to be in the following columns:

            **1**,\ **2**:
            longitude, latitude of station (**-:** option interchanges order)
            **3**,\ **4**:
            eastward, northward components of anisotropy vector (**-:** option interchanges order)

    **-Sr**\ *velscale/confidence*\ [**+f**\ *font*]

        Velocity ellipses in rotated convention. *velscale* sets the scaling of
        the velocity arrows. The *confidence* sets the 2-dimensional
        confidence limit for the ellipse, e.g., 0.95 for 95% confidence ellipse.
        *font* sets the font and size of the text [9p,Helvetica,black]. The ellipse will be
        filled with the color or shade specified by the |-G| option [default
        transparent]. The arrow and the circumference of the ellipse will be
        drawn with the pen attributes specified by the |-W| option. Parameters
        are expected to be in the following columns:

            **1**,\ **2**:
            longitude, latitude, of station (**-:** option interchanges order)
            **3**,\ **4**:
            eastward, northward velocity (**-:** option interchanges order)
            **5**,\ **6**:
            semi-major, semi-minor axes
            **7**:
            counter-clockwise angle, in degrees, from horizontal axis to major axis of ellipse.
            **8**:
            name of station (optional)

    **-Sw**\ *wedgescale/wedgemag*

        Rotational wedges. *wedgescale* sets the size of the wedges. Values are
        multiplied by *wedgemag* before plotting. For example, setting
        *wedgemag* to 1.e7 works well for rotations of the order of 100
        nanoradians/yr. Use **-G** to set the fill color or shade for the wedge,
        and **-E** to set the color or shade for the uncertainty. Parameters are
        expected to be in the following columns:

            **1**,\ **2**:
            longitude, latitude, of station (**-:** option interchanges order)
            **3**:
            rotation in radians
            **4**:
            rotation uncertainty in radians

    **-Sx**\ *cross_scale*

        gives Strain crosses. *cross_scale* sets the size of the cross. Parameters
        are expected to be in the following columns:

            **1**,\ **2**:
            longitude, latitude, of station (**-:** option interchanges order)
            **3**:
            eps1, the most extensional eigenvalue of strain tensor, with
            extension taken positive.
            **4**:
            eps2, the most compressional eigenvalue of strain tensor, with extension taken positive.
            **5**:
            azimuth of eps2 in degrees CW from North.

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

.. _-A:

**-A**\ *parameters*
    Modify vector parameters. For vector heads, append vector head *size* [Default is 9p].
    See `Vector Attributes`_ for specifying additional attributes.

.. _-B:

.. include:: ../../explain_-B.rst_

.. _-D:

**-D**\ *Sigma\_scale*
    can be used to rescale the uncertainties of velocities (**-Se** and
    **-Sr**) and rotations (**-Sw**). Can be combined with the *confidence* variable.

.. _-E:

**-E**\ *fill* :ref:`(more ...) <-Gfill_attrib>`
    Sets the color or shade used for filling uncertainty wedges
    (**-Sw**) or velocity error ellipses (**-Se** or **-Sr**). [If
    **-E** is not specified, the uncertainty regions will be transparent.]

.. _-G:

**-G**\ *fill* :ref:`(more ...) <-Gfill_attrib>`
    Select color or pattern for filling of symbols or polygons [Default is no fill].

.. _-L:

**-L**
    Draw lines. Ellipses and fault planes will have their outlines drawn
    using current pen (see **-W**).

.. _-N:

**-N**
    Do **NOT** skip symbols that fall outside the frame boundary
    specified by **-R**. [Default plots symbols inside frame only].

.. _-U:

.. include:: ../../explain_-U.rst_

.. _-V:

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

.. _-W:

**-W**
    Set pen attributes for velocity arrows, ellipse circumference and
    fault plane edges. [Defaults: width = default, color = black, style = solid].

.. _-X:

.. include:: ../../explain_-XY.rst_

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.. include:: ../../explain_-di.rst_

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.. include:: ../../explain_-e.rst_

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.. include:: ../../explain_-h.rst_

.. include:: ../../explain_-icols.rst_

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.. include:: ../../explain_perspective.rst_

.. include:: ../../explain_-qi.rst_
.. include:: ../../explain_-t.rst_
.. include:: ../../explain_colon.rst_
.. include:: ../../explain_help.rst_

.. include:: ../../explain_vectors.rst_