Source code for pygmt.figure
"""
Define the Figure class that handles all plotting.
"""
import base64
import os
from pathlib import Path, PurePath
from tempfile import TemporaryDirectory
from typing import Literal
try:
import IPython
_HAS_IPYTHON = True
except ImportError:
_HAS_IPYTHON = False
import numpy as np
from pygmt.clib import Session
from pygmt.exceptions import GMTInvalidInput
from pygmt.helpers import launch_external_viewer, unique_name
def _get_default_display_method() -> Literal["external", "notebook", "none"]:
"""
Get the default method to display preview images.
The function checks the current environment and determines the most suitable method
to display preview images when calling :meth:`pygmt.Figure.show`. Valid display
methods are:
- ``"external"``: External PDF preview using the default PDF viewer
- ``"notebook"``: Inline PNG preview in the current notebook
- ``"none"``: Disable image preview
The default display method is ``"notebook"`` in the Jupyter notebook environment,
and ``"external"`` in other cases.
Setting environment variable :term:`PYGMT_USE_EXTERNAL_DISPLAY` to ``"false"`` can
disable image preview in external viewers. It's useful when running the tests and
building the documentation to avoid popping up windows.
Returns
-------
method
The default display method.
"""
# Check if an IPython kernel is running.
if _HAS_IPYTHON and (ipy := IPython.get_ipython()) and "IPKernelApp" in ipy.config:
return "notebook"
# Check if the environment variable PYGMT_USE_EXTERNAL_DISPLAY is set to "false".
if os.environ.get("PYGMT_USE_EXTERNAL_DISPLAY", "true").lower() == "false":
return "none"
# Fallback to using the external viewer.
return "external"
# A registry of all figures that have had "show" called in this session.
# This is needed for the sphinx-gallery scraper in pygmt/sphinx_gallery.py
SHOWED_FIGURES = []
# Configurations for figure display.
SHOW_CONFIG = {
"method": _get_default_display_method(), # The image preview display method.
}
[docs]
class Figure:
"""
A GMT figure to handle all plotting.
Use the plotting methods of this class to add elements to the figure. You can
preview the figure using :meth:`pygmt.Figure.show` and save the figure to a file
using :meth:`pygmt.Figure.savefig`.
Examples
--------
>>> import pygmt
>>> fig = pygmt.Figure()
>>> fig.basemap(region=[0, 360, -90, 90], projection="W15c", frame=True)
>>> fig.savefig("my-figure.png")
>>> # Make sure the figure file is generated and clean it up
>>> from pathlib import Path
>>> assert Path("my-figure.png").exists()
>>> Path("my-figure.png").unlink()
The plot region can be specified through ISO country codes (for example, ``"JP"``
for Japan):
>>> import pygmt
>>> fig = pygmt.Figure()
>>> fig.basemap(region="JP", projection="M7c", frame=True)
>>> # The fig.region attribute shows the WESN bounding box for the figure
>>> print(", ".join(f"{i:.2f}" for i in fig.region))
122.94, 145.82, 20.53, 45.52
"""
def __init__(self):
self._name = unique_name()
self._preview_dir = TemporaryDirectory(prefix=f"{self._name}-preview-")
self._activate_figure()
def __del__(self):
"""
Clean up the temporary directory that stores the previews.
"""
if hasattr(self, "_preview_dir"):
self._preview_dir.cleanup()
def _activate_figure(self):
"""
Start and/or activate the current figure.
All plotting commands run afterward will append to this figure.
"""
fmt = "-" # Passing format "-" tells pygmt.end to not produce any files.
with Session() as lib:
lib.call_module(module="figure", args=[self._name, fmt])
def _preprocess(self, **kwargs):
"""
Call the ``figure`` module before each plotting command to ensure we're plotting
to this particular figure.
"""
self._activate_figure()
return kwargs
@property
def region(self) -> np.ndarray:
"""
The geographic WESN bounding box for the current figure.
"""
self._activate_figure()
with Session() as lib:
wesn = lib.extract_region()
return wesn
[docs]
def savefig(
self,
fname: str | PurePath,
transparent: bool = False,
crop: bool = True,
anti_alias: bool = True,
show: bool = False,
worldfile: bool = False,
**kwargs,
):
"""
Save the figure to an image file.
Supported image formats and their extensions:
**Raster image formats**
- BMP (``.bmp``)
- JPEG (``.jpg`` or ``.jpeg``)
- GeoTIFF (``.tiff``)
- PNG (``.png``)
- PPM (``.ppm``)
- TIFF (``.tif``)
**Vector image formats**
- EPS (``.eps``)
- PDF (``.pdf``)
Besides the above formats, you can also save the figure to a KML file
(``.kml``), with a companion PNG file generated automatically. The KML file can
be viewed in Google Earth.
You can pass in any keyword arguments that :meth:`pygmt.Figure.psconvert`
accepts.
Parameters
----------
fname
The desired figure file name, including the extension. See the list of
supported formats and their extensions above.
transparent
Use a transparent background for the figure. Only valid for PNG format and
the PNG file asscoiated with KML format.
crop
Crop the figure canvas (page) to the plot area.
anti_alias
Use anti-aliasing when creating raster images. Ignored if creating vector
images. More specifically, it passes the arguments ``"t2"`` and ``"g2"`` to
the ``anti_aliasing`` parameter of :meth:`pygmt.Figure.psconvert`.
show
Display the figure in an external viewer.
worldfile
Create a companion `world file <https://en.wikipedia.org/wiki/World_file>`__
for the figure. The world file will have the same name as the figure file
but with different extension (e.g., ``.tfw`` for ``.tif``). See
https://en.wikipedia.org/wiki/World_file#Filename_extension for the
convention of world file extensions. This parameter only works for raster
image formats (except GeoTIFF).
**kwargs : dict
Additional keyword arguments passed to :meth:`pygmt.Figure.psconvert`. Valid
parameters are ``dpi``, ``gs_path``, ``gs_option``, ``resize``,
``bb_style``, and ``verbose``.
"""
# All supported formats
fmts = {
"bmp": "b",
"eps": "e",
"jpg": "j",
"kml": "G" if transparent is True else "g",
"pdf": "f",
"png": "G" if transparent is True else "g",
"ppm": "m",
"tif": "t",
"tiff": None, # GeoTIFF doesn't need the -T option
}
fname = Path(fname)
prefix, suffix = fname.with_suffix("").as_posix(), fname.suffix
ext = suffix[1:].lower() # Remove the . and normalize to lowercase
match ext:
case "jpeg": # Alias jpeg to jpg
ext = "jpg"
case "tiff": # GeoTIFF
kwargs["W"] = "+g"
case "kml": # KML
kwargs["W"] = "+k"
case "ps":
msg = "Extension '.ps' is not supported. Use '.eps' or '.pdf' instead."
raise GMTInvalidInput(msg)
case ext if ext not in fmts:
msg = f"Unknown extension '.{ext}'."
raise GMTInvalidInput(msg)
if transparent and ext not in {"kml", "png"}:
msg = f"Transparency unavailable for '{ext}', only for png and kml."
raise GMTInvalidInput(msg)
if anti_alias:
kwargs["Qt"] = 2
kwargs["Qg"] = 2
if worldfile:
if ext in {"eps", "kml", "pdf", "tiff"}:
msg = f"Saving a world file is not supported for '{ext}' format."
raise GMTInvalidInput(msg)
kwargs["W"] = True
# pytest-mpl v0.17.0 added the "metadata" parameter to Figure.savefig, which is
# not recognized. So remove it before calling Figure.psconvert.
kwargs.pop("metadata", None)
self.psconvert(prefix=prefix, fmt=fmts[ext], crop=crop, **kwargs)
# Remove the .pgw world file if exists. Not necessary after GMT 6.5.0.
# See upstream fix https://github.com/GenericMappingTools/gmt/pull/7865
if ext == "tiff":
fname.with_suffix(".pgw").unlink(missing_ok=True)
# Rename if file extension doesn't match the input file suffix.
if ext != suffix[1:]:
fname.with_suffix("." + ext).rename(fname)
if show:
launch_external_viewer(str(fname))
[docs]
def show(
self,
method: Literal["external", "notebook", "none", None] = None,
dpi: int = 300,
width: int = 500,
waiting: float = 0.5,
**kwargs,
):
"""
Display a preview of the figure.
Inserts the preview in the Jupyter notebook output if available, otherwise opens
it in the default viewer for your operating system (falls back to the default
web browser).
Use :func:`pygmt.set_display` to select the default display method
(``"notebook"``, ``"external"``, ``"none"`` or ``None``).
The ``method`` parameter allows to override the default display method for the
current figure. The parameters ``dpi`` and ``width`` can be used to control the
resolution and dimension of the figure in the notebook.
The external viewer can be disabled by setting the environment variable
:term:`PYGMT_USE_EXTERNAL_DISPLAY` to ``"false"``. This is useful when running
tests and building the documentation to avoid popping up windows.
The external viewer does not block the current process, thus it's necessary to
suspend the execution of the current process for a short while after launching
the external viewer, so that the preview image won't be deleted before the
external viewer tries to open it. Set the ``waiting`` parameter to a larger
number if the image viewer on your computer is slow to open the figure.
Parameters
----------
method
The method to display the current image preview. Choose from:
- ``"external"``: External PDF preview using the default PDF viewer
- ``"notebook"``: Inline PNG preview in the current notebook
- ``"none"``: Disable image preview
- ``None``: Reset to the default display method
The default display method is ``"external"`` in Python consoles and
``"notebook"`` in Jupyter notebooks, but can be changed by
:func:`pygmt.set_display`.
dpi
The image resolution (dots per inch) in Jupyter notebooks.
width
The image width (in pixels) in Jupyter notebooks.
waiting
Suspend the execution of the current process for a given number of seconds
after launching an external viewer. Only works if ``method="external"``.
**kwargs : dict
Additional keyword arguments passed to :meth:`pygmt.Figure.psconvert`. Valid
parameters are ``gs_path``, ``gs_option``, ``resize``, ``bb_style``, and
``verbose``.
"""
# Module level variable to know which figures had their show method called.
# Needed for the sphinx-gallery scraper.
SHOWED_FIGURES.append(self)
# Set the display method
if method is None:
method = SHOW_CONFIG["method"]
match method:
case "notebook":
if not _HAS_IPYTHON:
msg = (
"Notebook display is selected, but IPython is not available. "
"Make sure you have IPython installed, "
"or run the script in a Jupyter notebook."
)
raise ImportError(msg)
png = self._preview(
fmt="png", dpi=dpi, anti_alias=True, as_bytes=True, **kwargs
)
IPython.display.display(IPython.display.Image(data=png, width=width))
case "external":
pdf = self._preview(
fmt="pdf", dpi=dpi, anti_alias=False, as_bytes=False, **kwargs
)
launch_external_viewer(pdf, waiting=waiting)
case "none":
pass # Do nothing
case _:
msg = (
f"Invalid display method '{method}'. "
"Valid values are 'external', 'notebook', 'none' or None."
)
raise GMTInvalidInput(msg)
def _preview(self, fmt: str, dpi: int, as_bytes: bool = False, **kwargs):
"""
Grab a preview of the figure.
Parameters
----------
fmt
The image format. Can be any extension that :meth:`pygmt.Figure.savefig`
recognizes.
dpi
The image resolution (dots per inch).
as_bytes
If ``True``, will load the binary contents of the image as a bytes object,
and return that instead of the file name.
Returns
-------
preview
If ``as_bytes = False``, this is the file name of the preview image file.
Otherwise, it is the file content loaded as a bytes object.
"""
fname = Path(self._preview_dir.name) / f"{self._name}.{fmt}"
self.savefig(fname, dpi=dpi, **kwargs)
if as_bytes:
return fname.read_bytes()
return fname
def _repr_png_(self):
"""
Show a PNG preview if the object is returned in an interactive shell.
For the Jupyter notebook or IPython Qt console.
"""
png = self._preview(fmt="png", dpi=70, anti_alias=True, as_bytes=True)
return png
def _repr_html_(self):
"""
Show the PNG image embedded in HTML with a controlled width.
Looks better than the raw PNG.
"""
raw_png = self._preview(fmt="png", dpi=300, anti_alias=True, as_bytes=True)
base64_png = base64.encodebytes(raw_png)
html = '<img src="data:image/png;base64,{image}" width="{width}px">'
return html.format(image=base64_png.decode("utf-8"), width=500)
from pygmt.src import ( # type: ignore[misc]
basemap,
coast,
colorbar,
contour,
grdcontour,
grdimage,
grdview,
histogram,
image,
inset,
legend,
logo,
meca,
plot,
plot3d,
psconvert,
rose,
set_panel,
shift_origin,
solar,
subplot,
ternary,
text,
tilemap,
timestamp,
velo,
wiggle,
)
[docs]
def set_display(method: Literal["external", "notebook", "none", None] = None):
"""
Set the display method when calling :meth:`pygmt.Figure.show`.
Parameters
----------
method
The method to display an image preview. Choose from:
- ``"external"``: External PDF preview using the default PDF viewer
- ``"notebook"``: Inline PNG preview in the current notebook
- ``"none"``: Disable image preview
- ``None``: Reset to the default display method, which is either ``"external"``
in Python consoles or ``"notebook"`` in Jupyter notebooks.
Examples
--------
Let's assume that you're using a Jupyter Notebook:
>>> import pygmt
>>> fig = pygmt.Figure()
>>> fig.basemap(region=[0, 10, 0, 10], projection="X10c/5c", frame=True)
>>> fig.show() # Will display a PNG image in the current notebook
>>>
>>> # Set the display method to "external"
>>> pygmt.set_display(method="external") # doctest: +SKIP
>>> fig.show() # Will display a PDF image using the default PDF viewer
>>>
>>> # Set the display method to "none"
>>> pygmt.set_display(method="none")
>>> fig.show() # Will not show any image
>>>
>>> # Reset to the default display method
>>> pygmt.set_display(method=None)
>>> fig.show() # Again, will show a PNG image in the current notebook
"""
match method:
case "external" | "notebook" | "none":
SHOW_CONFIG["method"] = method
case None:
SHOW_CONFIG["method"] = _get_default_display_method()
case _:
msg = (
f"Invalid display method '{method}'. "
"Valid values are 'external', 'notebook', 'none' or None."
)
raise GMTInvalidInput(msg)