"""
colorbar - Plot gray scale or color scale bar.
"""
from collections.abc import Sequence
from typing import Literal
from pygmt._typing import AnchorCode
from pygmt.alias import Alias, AliasSystem
from pygmt.clib import Session
from pygmt.exceptions import GMTValueError
from pygmt.helpers import build_arg_list, fmt_docstring, use_alias
from pygmt.helpers.utils import is_nonstr_iter
from pygmt.params import Box, Position
from pygmt.src._common import _parse_position
__doctest_skip__ = ["colorbar"]
def _alias_option_D( # noqa: N802, PLR0913
position=None,
length=None,
width=None,
orientation=None,
reverse=False,
nan=False,
nan_position=None,
fg_triangle=False,
bg_triangle=False,
triangle_height=None,
move_text=None,
label_as_column=False,
):
"""
Return a list of Alias objects for the -D option.
"""
# Build the +e modifier from fg_triangle/bg_triangle/triangle_height
if fg_triangle and bg_triangle:
modifier_e = ""
elif fg_triangle:
modifier_e = "f"
elif bg_triangle:
modifier_e = "b"
else:
modifier_e = None
if modifier_e is not None and triangle_height is not None:
modifier_e = f"{modifier_e}{triangle_height}"
# Build the +m modifier from move_text/label_as_column
modifier_m = None
if move_text or label_as_column:
modifier_m = ""
_valids = {"annotations", "label", "unit"}
if move_text is not None:
if (isinstance(move_text, str) and move_text not in _valids) or (
is_nonstr_iter(move_text) and not all(v in _valids for v in move_text)
):
raise GMTValueError(
move_text,
description="move_text",
choices=_valids,
)
if isinstance(move_text, str):
modifier_m = move_text[0]
elif is_nonstr_iter(move_text):
modifier_m = "".join(item[0] for item in move_text)
if label_as_column:
modifier_m += "c"
return [
Alias(position, name="position"),
Alias(length, name="length", prefix="+w"), # +wlength/width
Alias(width, name="width", prefix="/"),
Alias(
orientation,
name="orientation",
mapping={"horizontal": "+h", "vertical": "+v"},
),
Alias(reverse, name="reverse", prefix="+r"),
Alias(
nan,
name="nan",
prefix="+n" if nan_position in {"start", None} else "+N",
),
Alias(
modifier_e,
name="fg_triangle/bg_triangle/triangle_height",
prefix="+e",
),
Alias(modifier_m, name="move_text/label_as_column", prefix="+m"),
]
@fmt_docstring
@use_alias(C="cmap", L="equalsize", Z="zfile")
def colorbar( # noqa: PLR0913
self,
position: Position | Sequence[float | str] | AnchorCode | None = None,
length: float | str | None = None,
width: float | str | None = None,
orientation: Literal["horizontal", "vertical"] | None = None,
reverse: bool = False,
nan: bool = False,
nan_position: Literal["start", "end"] | None = None,
bg_triangle: bool = False,
fg_triangle: bool = False,
triangle_height: float | None = None,
move_text: Literal["annotations", "label", "unit"] | Sequence[str] | None = None,
label_as_column: bool = False,
box: Box | bool = False,
truncate: Sequence[float] | None = None,
shading: float | Sequence[float] | bool = False,
log: bool = False,
scale: float | None = None,
projection: str | None = None,
region: Sequence[float | str] | str | None = None,
frame: str | Sequence[str] | bool = False,
verbose: Literal["quiet", "error", "warning", "timing", "info", "compat", "debug"]
| bool = False,
panel: int | Sequence[int] | bool = False,
perspective: float | Sequence[float] | str | bool = False,
transparency: float | None = None,
**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.
.. note::
For GMT >=6.5.0, the fontsizes of the colorbar x-label, x-annotations,
and y-label are scaled based on the width of the colorbar following
:math:`\sqrt{colorbar\_width / 15}`. To set a desired fontsize via the
GMT default parameters :gmt-term:`FONT_ANNOT_PRIMARY`,
:gmt-term:`FONT_ANNOT_SECONDARY`, and :gmt-term:`FONT_LABEL` (or jointly
:gmt-term:`FONT`) users have to divide the desired fontsize by the value
calculated with the formula given above before passing it to the default
parameters. To only affect fontsizes related to the colorbar, the
defaults can be changed locally only using ``with pygmt.config(...):``.
Full GMT docs at :gmt-docs:`colorbar.html`.
$aliases
- B = frame
- F = box
- G = truncate
- I = shading
- J = projection
- Q = log
- R = region
- V = verbose
- W = scale
- c = panel
- p = perspective
- t = transparency
.. hlist::
:columns: 1
- D = position, **+w**: length/width, **+h**/**+v**: orientation,
**+r**: reverse, **+n**: nan/nan_position,
**+e**: fg_triangle/bg_triangle/triangle_height,
**+m**: move_text/label_as_column
Parameters
----------
$cmap
position
Position of the colorbar on the plot. It can be specified in multiple ways:
- A :class:`pygmt.params.Position` object to fully control the reference point,
anchor point, and offset.
- A sequence of two values representing the x- and y-coordinates in plot
coordinates, e.g., ``(1, 2)`` or ``("1c", "2c")``.
- A :doc:`2-character justification code </techref/justification_codes>` for a
position inside the plot, e.g., ``"TL"`` for Top Left corner inside the plot.
If not specified, defaults to bottom-center outside of the plot.
length
width
Length and width of the colorbar. If length is given with a unit ``%`` then it
is in percentage of the corresponding plot side dimension (i.e., plot width for
a horizontal colorbar, or plot height for a vertical colorbar). If width is
given with unit ``%`` then it is in percentage of the bar length. [Length
defaults to 80% of the corresponding plot side dimension, and width defaults
to 4% of the bar length].
orientation
Set the colorbar orientation to either ``"horizontal"`` or ``"vertical"``.
[Default is vertical, unless ``position`` is set to bottom-center or top-center
with ``cstype="outside"`` or ``cstype="inside"``, then horizontal is the
default].
reverse
Reverse the positive direction of the bar.
nan
Draw a rectangle filled with the NaN color (via the **N** entry in the CPT or
:gmt-term:`COLOR_NAN` if no such entry) at the start or end of the colorbar
(controlled via ``nan_position``). If a string is given, use that string as the
label for the NaN color.
nan_position
Set the position of the NaN rectangle. Choose either ``"start"`` or ``"end"`` to
place the NaN color rectangle at the start or end of the colorbar [Default is
``"start"``].
bg_triangle
fg_triangle
If ``True``, draw triangles for the back- or foreground colors [Default is
no triangles]. The back- and/or foreground colors are taken from the **B**
and **F** entries in the CPT. If no such entries exist, then the system default
colors for **B** and **F** are used instead (:gmt-term:`COLOR_BACKGROUND` and
:gmt-term:`COLOR_FOREGROUND`).
triangles_height
Height of the triangles for back- and foreground colors [Default is half
of the bar width].
move_text
Move text (annotations, label, and unit) to opposite side. Accept a sequence of
strings containing one or more of ``"annotations"``, ``"label"``, and
``"unit"``. The default placements of these texts depend on the colorbar
orientation and position.
label_as_column
Print a vertical label as a column of characters (does not work with special
characters).
box
Draw a background box behind the colorbar. If set to ``True``, a simple
rectangular box is drawn using :gmt-term:`MAP_FRAME_PEN`. To customize the box
appearance, pass a :class:`pygmt.params.Box` object to control style, fill, pen,
and other box properties.
truncate
(*zlow*, *zhigh*).
Truncate the incoming CPT so that the lowest and highest z-levels are to *zlow*
and *zhigh*. If one of these equal NaN then we leave that end of the CPT alone.
The truncation takes place before the plotting.
scale
Multiply all z-values in the CPT by the provided scale. By default, the CPT is
used as is.
shading
Add illumination effects [Default is no illumination].
- If ``True``, a default intensity range of -1 to +1 is used.
- Passing a single numerical value *max_intens* sets the range of intensities
from *-max_intens* to *+max_intens*.
- Passing a sequence of two numerical values (*low*, *high*) sets the intensity
range from *low* to *high* to specify an asymmetric range.
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
Select logarithmic scale and power of ten annotations. All z-values in the CPT
will be converted to :math:`p = \log_{10}(z)` and only integer p values will be
annotated using the :math:`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.
$projection
$region
frame
Set colorbar boundary frame, labels, and axes attributes.
$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="SCM/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()
position = _parse_position(
position,
kwdict={
"length": length,
"width": width,
"orientation": orientation,
"reverse": reverse,
"nan": nan,
"nan_position": nan_position,
"bg_triangle": bg_triangle,
"fg_triangle": fg_triangle,
"triangle_height": triangle_height,
"move_text": move_text,
"label_as_column": label_as_column,
},
default=None, # Use GMT's default behavior if position is not provided.
)
aliasdict = AliasSystem(
D=_alias_option_D(
position=position,
length=length,
width=width,
orientation=orientation,
reverse=reverse,
nan=nan,
nan_position=nan_position,
bg_triangle=bg_triangle,
fg_triangle=fg_triangle,
triangle_height=triangle_height,
move_text=move_text,
label_as_column=label_as_column,
),
F=Alias(box, name="box"),
G=Alias(truncate, name="truncate", sep="/", size=2),
I=Alias(shading, name="shading", sep="/", size=2),
Q=Alias(log, name="log"),
W=Alias(scale, name="scale"),
).add_common(
B=frame,
J=projection,
R=region,
V=verbose,
c=panel,
p=perspective,
t=transparency,
)
aliasdict.merge(kwargs)
with Session() as lib:
lib.call_module(module="colorbar", args=build_arg_list(aliasdict))