hvPlot.contour#
- hvPlot.contour(x=None, y=None, z=None, colorbar=True, levels=5, logz=False, **kwds)[source]#
Line contour plot.
A contour plot displays isolines representing constant values in a 2D scalar field over gridded data.
Reference: https://hvplot.holoviz.org/ref/api/manual/hvplot.hvPlot.contour.html
Plotting options: https://hvplot.holoviz.org/ref/plotting_options/index.html
- Parameters:
- xstring, optional
The coordinate variable along the x-axis
- ystring, optional
The coordinate variable along the y-axis
- zstring, optional
The data variable to plot
- colorbar: boolean, optional
Whether to display a colorbar. Default is True.
- levels: int or list, optional
The number of contour lines to draw or a list of scalar values used to specify the contour levels. Default is 5.
- logz: bool, optional
Whether to apply log scaling to the z-axis. Default is False.
- **kwdsoptional
Additional keywords arguments are documented in Plotting Options. Run
hvplot.help('contour')for the full method documentation.
- Returns:
holoviews.element.Contours/ Panel objectYou can print the object to study its composition and run:
import holoviews as hv hv.help(the_holoviews_object)
to learn more about its parameters and options.
See also
contourfFilled contour plot.
References
Backend-specific styling options#
alpha, cmap, color, hover_alpha, hover_color, hover_line_alpha, hover_line_cap, hover_line_color, hover_line_dash, hover_line_dash_offset, hover_line_join, hover_line_width, line_alpha, line_cap, line_color, line_dash, line_dash_offset, line_join, line_width, muted, muted_alpha, muted_color, muted_line_alpha, muted_line_cap, muted_line_color, muted_line_dash, muted_line_dash_offset, muted_line_join, muted_line_width, nonselection_alpha, nonselection_color, nonselection_line_alpha, nonselection_line_cap, nonselection_line_color, nonselection_line_dash, nonselection_line_dash_offset, nonselection_line_join, nonselection_line_width, selection_alpha, selection_color, selection_line_alpha, selection_line_cap, selection_line_color, selection_line_dash, selection_line_dash_offset, selection_line_join, selection_line_width, visible
alpha, c, cmap, color, linestyle, linewidth, lw, visible
Examples#
Basic contour lines#
import hvplot.xarray # noqa
import numpy as np
import xarray as xr
x = y = np.linspace(-10, 10, 200)
X, Y = np.meshgrid(x, y)
Z = 10 * np.exp(-(X**2 + Y**2) / 20)
ds = xr.DataArray(Z, coords=[("y", y), ("x", x)], name="z").to_dataset()
ds.hvplot.contour(x="x", y="y", z="z", levels=10, cmap="viridis")
Let’s use a more realistic dataset and plot contours over a 2D field of air temperature for a single time slice.
import hvplot.xarray # noqa
ds = hvplot.sampledata.air_temperature("xarray").sel(time="2014-02-25 12:00")
ds.hvplot.contour(x='lon', y='lat', levels=20, cmap='viridis_r')
Specify contour levels and colobar label#
You can manually control contour levels by setting levels to a list of values, and add a colorbar label with clabel.
import hvplot.xarray # noqa
ds = hvplot.sampledata.air_temperature("xarray").sel(time="2014-02-25 12:00")
ds.hvplot.contour(
x='lon', y='lat', z='air', levels=list(range(240, 300, 5)),
cmap='plasma_r', line_width=1.2, clabel='Air Temperature (K)',
)