"""
Functions to load sample data.
"""
import pandas as pd
from pygmt.src import which
[docs]def load_japan_quakes():
"""
Load a table of earthquakes around Japan as a pandas.Dataframe.
Data is from the NOAA NGDC database. This is the ``@tut_quakes.ngdc``
dataset used in the GMT tutorials.
The data are downloaded to a cache directory (usually ``~/.gmt/cache``) the
first time you invoke this function. Afterwards, it will load the data from
the cache. So you'll need an internet connection the first time around.
Returns
-------
data : pandas.Dataframe
The data table. Columns are year, month, day, latitude, longitude,
depth (in km), and magnitude of the earthquakes.
"""
fname = which("@tut_quakes.ngdc", download="c")
data = pd.read_csv(fname, header=1, sep=r"\s+")
data.columns = [
"year",
"month",
"day",
"latitude",
"longitude",
"depth_km",
"magnitude",
]
return data
[docs]def load_ocean_ridge_points():
"""
Load a table of ocean ridge points for the entire world as a
pandas.DataFrame.
This is the ``@ridge.txt`` dataset used in the GMT tutorials.
The data are downloaded to a cache directory (usually ``~/.gmt/cache``) the
first time you invoke this function. Afterwards, it will load the data from
the cache. So you'll need an internet connection the first time around.
Returns
-------
data : pandas.Dataframe
The data table. Columns are longitude and latitude.
"""
fname = which("@ridge.txt", download="c")
data = pd.read_csv(
fname, sep=r"\s+", names=["longitude", "latitude"], skiprows=1, comment=">"
)
return data
[docs]def load_sample_bathymetry():
"""
Load a table of ship observations of bathymetry off Baja California as a
pandas.DataFrame.
This is the ``@tut_ship.xyz`` dataset used in the GMT tutorials.
The data are downloaded to a cache directory (usually ``~/.gmt/cache``) the
first time you invoke this function. Afterwards, it will load the data from
the cache. So you'll need an internet connection the first time around.
Returns
-------
data : pandas.Dataframe
The data table. Columns are longitude, latitude, and bathymetry.
"""
fname = which("@tut_ship.xyz", download="c")
data = pd.read_csv(
fname, sep="\t", header=None, names=["longitude", "latitude", "bathymetry"]
)
return data
[docs]def load_usgs_quakes():
"""
Load a table of global earthquakes form the USGS as a pandas.Dataframe.
This is the ``@usgs_quakes_22.txt`` dataset used in the GMT tutorials.
The data are downloaded to a cache directory (usually ``~/.gmt/cache``) the
first time you invoke this function. Afterwards, it will load the data from
the cache. So you'll need an internet connection the first time around.
Returns
-------
data : pandas.Dataframe
The data table. Use ``print(data.describe())`` to see the available
columns.
"""
fname = which("@usgs_quakes_22.txt", download="c")
data = pd.read_csv(fname)
return data