Add LineCollection plot

[Illviljan]

This adds a line plotter based on LineCollections, called .lines.

I wanted to replace darray.plot() with using LineCollection instead. But unfortunately due to how many cases are supported (and tested in xarray) darray.plot() will continue using plt.plot.

Examples:

https://www.reddit.com/r/dataisbeautiful/comments/1d4ahr1/oc_north_atlantic_sea_surface_temperature_anomaly/

Got this working with xarray:

Details

# https://www.reddit.com/r/dataisbeautiful/comments/1d4ahr1/oc_north_atlantic_sea_surface_temperature_anomaly/#lightbox# https://github.com/afinemax/climate_change_bot/blob/main/bot.pyimportrequestsimportnumpyasnpimportmatplotlib.pyplotaspltimportxarrayasxrdefdownload_json(url):
try:
response=requests.get(url)
response.raise_for_status() # Raise an exception for unsuccessful responses (4xx, 5xx)json_data=response.json()
returnjson_dataexceptrequests.exceptions.RequestExceptionase:
print(f"Error downloading JSON: {e}")
returnNoneurl=r"https://climatereanalyzer.org/clim/sst_daily/json/oisst2.1_natlan1_sst_day.json"sst_daily_data=download_json(url)
data= []
years= []
foriinrange(len(sst_daily_data) -3):
years.append((sst_daily_data[i]["name"]))
data.append(sst_daily_data[i]["data"])
# convert data from list into nd arrdata=np.asarray(data, dtype=float) # first index is year, 2nd index is day# Datetimes not working for some unrelated reason:# ds = xr.Dataset(# data_vars=dict(temperature=(("year", "day"), data)),# coords=dict(# year=np.array(dict_names, dtype="datetime64[D]"),# day=np.arange(data.shape[-1], dtype="timedelta64[D]"),# ),# )ds=xr.Dataset(
data_vars=dict(
temperature=(
("year", "day"),
data,
dict(
long_name="Daily North Atlantic (0-60N) Sea Surface Temperature (SST)",
units="degC",
),
)
),
coords=dict(
year=np.array(years, dtype=int),
day=np.arange(data.shape[-1], dtype=int),
),
)
plt.figure()
ds.plot.lines(x="day", y="temperature", hue="year")

Calling it lines since scatter is not called path_collection:

• PathCollection (Very low-level, e.g. no datetime handling) -> plt.scatter (Handles datetime etc.)-> xr.plot.scatter
• LineCollection (Very low-level, e.g. no datetime handling) -> _line (Handles datetime etc. Pretty much a copy of plt.scatter) -> xr.plot.lines

Seaborns new object-based plotting uses lines as well with similar argument:
https://seaborn.pydata.org/generated/seaborn.objects.Line.html
https://seaborn.pydata.org/generated/seaborn.objects.Lines.html

xref:
#4820
#5622

[Illviljan]

Scatter vs. Lines:

Details

ds=xr.tutorial.scatter_example_dataset(seed=42)
hue_="y"x_="y"size_="y"z_="z"fig=plt.figure()
ax=fig.add_subplot(1, 2, 1, projection='3d')
ds.A.sel(w="one").plot.lines(x=x_, z=z_, hue=hue_, linewidth=size_, ax=ax)
ax=fig.add_subplot(1, 2, 2, projection='3d')
ds.A.sel(w="one").plot.scatter(x=x_, z=z_, hue=hue_, markersize=size_, ax=ax)