# Overlay ¶

Title
Overlay Container
Dependencies
Matplotlib
Backends
Matplotlib
Bokeh
In [1]:
import numpy as np
import holoviews as hv
hv.extension('matplotlib')


A Overlay is a collection of HoloViews objects that are related in some way, to be displayed simultanously, overlaid in the space space. Like  Layout  ,  GridSpace  and  NdOverlay  a  Overlay  is not dictionary like: it holds potentially heterogeneous types without any dimensioned keys.

A  Overlay  cannot contain any other container type other than  NdOverlay  but can contain any HoloViews elements. See Building Composite Objects for more details on how to compose containers. It is best to learn about  Overlay  and  Layout  together as they are very closely related objects that share many core concepts.

###  Overlay  is a heterogeneous collection ¶

You can build a  Overlay  between any two HoloViews objects (which can have different types) using the  *  operator:

In [2]:
xvals = [0.1* i for i in range(100)]
curve =  hv.Curve((xvals, [np.sin(x) for x in xvals]))
scatter =  hv.Scatter((xvals[::5], np.linspace(0,1,20)))
curve * scatter

Out[2]:

In this example, we have a  Overlay  composed of a  Curve  element and a  Scatter  element.

For more information about both  Overlay  and  Layout  , see the Composing_Elements user guide.