"""
colorbar - Plot gray scale or color scale bar.
"""
from pygmt.clib import Session
from pygmt.helpers import build_arg_list, fmt_docstring, kwargs_to_strings, use_alias
__doctest_skip__ = ["colorbar"]
@fmt_docstring
@use_alias(
B="frame",
C="cmap",
D="position",
F="box",
G="truncate",
I="shading",
J="projection",
L="equalsize",
Q="log",
R="region",
V="verbose",
W="scale",
Z="zfile",
c="panel",
p="perspective",
t="transparency",
)
@kwargs_to_strings(
R="sequence", G="sequence", I="sequence", c="sequence_comma", p="sequence"
)
def colorbar(self, **kwargs):
r"""
Plot gray scale or color scale bar.
Both horizontal and vertical colorbars are supported. For CPTs with
gradational colors (i.e., the lower and upper boundary of an interval
have different colors) we will interpolate to give a continuous scale.
Variations in intensity due to shading/illumination may be displayed by
setting the ``shading`` parameter. Colors may be spaced according to a
linear scale, all be equal size, or by providing a file with individual
tile widths.
Full GMT docs at :gmt-docs:`colorbar.html`.
{aliases}
Parameters
----------
frame : str or list
Set colorbar boundary frame, labels, and axes attributes.
{cmap}
position : str
[**g**\|\ **j**\|\ **J**\|\ **n**\|\ **x**]\ *refpoint*\
[**+w**\ *length*\ [/\ *width*]]\ [**+e**\ [**b**\|\ **f**][*length*]]\
[**+h**\|\ **v**][**+j**\ *justify*]\
[**+m**\ [**a**\|\ **c**\|\ **l**\|\ **u**]]\
[**+n**\ [*txt*]][**+o**\ *dx*\ [/*dy*]].
Define the reference point on the map for the color scale using one of
four coordinate systems: (1) Use **g** for map (user) coordinates, (2)
use **j** or **J** for setting *refpoint* via a 2-character
justification code that refers to the (invisible) map domain rectangle,
(3) use **n** for normalized (0-1) coordinates, or (4) use **x** for
plot coordinates (inches, cm, etc.). All but **x** requires both
``region`` and ``projection`` to be specified. Append **+w** followed
by the length and width of the colorbar. If width is not specified
then it is set to 4% of the given length. Give a negative length to
reverse the scale bar. Append **+h** to get a horizontal scale
[Default is vertical (**+v**)]. By default, the anchor point on the
scale is assumed to be the bottom left corner (**BL**), but this can
be changed by appending **+j** followed by a 2-character
justification code *justify*.
box : bool or str
[**+c**\ *clearances*][**+g**\ *fill*][**+i**\ [[*gap*/]\ *pen*]]\
[**+p**\ [*pen*]][**+r**\ [*radius*]][**+s**\ [[*dx*/*dy*/][*shade*]]].
If set to ``True``, draw a rectangular border around the color scale.
Alternatively, specify a different pen with **+p**\ *pen*. Add
**+g**\ *fill* to fill the scale panel [Default is no fill]. Append
**+c**\ *clearance* where *clearance* is either gap, xgap/ygap, or
lgap/rgap/bgap/tgap where these items are uniform, separate in x- and
y-direction, or individual side spacings between scale and border.
Append **+i** to draw a secondary, inner border as well. We use a
uniform gap between borders of 2p and the :gmt-term:`MAP_DEFAULTS_PEN`
unless other values are specified. Append **+r** to draw rounded
rectangular borders instead, with a 6p corner radius. You can override
this radius by appending another value. Finally, append **+s** to draw
an offset background shaded region. Here, *dx/dy* indicates the shift
relative to the foreground frame [Default is ``"4p/-4p"``] and shade
sets the fill style to use for shading [Default is ``"gray50"``].
truncate : list or str
*zlo*/*zhi*.
Truncate the incoming CPT so that the lowest and highest z-levels are
to *zlo* and *zhi*. If one of these equal NaN then we leave that end of
the CPT alone. The truncation takes place before the plotting.
scale : float
Multiply all z-values in the CPT by the provided scale. By default,
the CPT is used as is.
shading : str, list, or bool
Add illumination effects. Passing a single numerical value sets the
range of intensities from -value to +value. If not specified, 1 is
used. Alternatively, set ``shading=[low, high]`` to specify an
asymmetric intensity range from *low* to *high*. [Default is no
illumination].
equalsize : float or str
[**i**]\ [*gap*].
Equal-sized color rectangles. By default, the rectangles are scaled
according to the z-range in the CPT (see also ``zfile``). If *gap* is
appended and the CPT is discrete each annotation is centered on each
rectangle, using the lower boundary z-value for the annotation. If
**i** is prepended the interval range is annotated instead. If
``shading`` is used each rectangle will have its constant color
modified by the specified intensity.
log : bool
Select logarithmic scale and power of ten annotations. All z-values
in the CPT will be converted to p = log10(z) and only integer p-values
will be annotated using the 10^p format [Default is linear scale].
zfile : str
File with colorbar-width per color entry. By default, the width of the
entry is scaled to the color range, i.e., z = 0-100 gives twice the
width as z = 100-150 (see also ``equalsize``). **Note**: The widths
may be in plot distance units or given as relative fractions and will
be automatically scaled so that the sum of the widths equals the
requested colorbar length.
{verbose}
{panel}
{perspective}
{transparency}
Example
-------
>>> import pygmt
>>> # Create a new figure instance with pygmt.Figure()
>>> fig = pygmt.Figure()
>>> # Create a basemap
>>> fig.basemap(region=[0, 10, 0, 3], projection="X10c/3c", frame=True)
>>> # Call the colorbar method for the plot
>>> fig.colorbar(
... # Set cmap to the "roma" CPT
... cmap="roma",
... # Label the x-axis "Velocity" and the y-axis "m/s"
... frame=["x+lVelocity", "y+lm/s"],
... )
>>> # Show the plot
>>> fig.show()
"""
self._activate_figure()
with Session() as lib:
lib.call_module(module="colorbar", args=build_arg_list(kwargs))