Let’s visualise big gridded data with Intake and XrViz

Harman Deep Singh
Jul 24 · 3 min read
Lake Ontario

Here is part 1 of this blog.

This post aims to share the ease of data input with Intake and interactive visualisation of xarray data with XrViz.

Quick Overview

Intake is a lightweight package for finding, investigating, loading and disseminating data. It is useful for all and acts as a common platform that everyone can use to smooth the progression of data from developers and providers to users.

XrViz is an interactive, in browser visualisation interface for Xarrays backed by the full power of the Python ecosystem. It allows controlled data points selection, massive rendering, data display, custom interaction and selection of fields for plotting in the browser using Xarray and PyViz(now HoloViz) collection of tools.

Data Input and Selection

One can simply add the data catalog in the intake gui as follows :

import intakegui = intake.gui
gui.add(‘xarray_data.yml’)
gui
Intake GUI

A catalog can have several dataset sources. The selected data can be loaded using:

data = gui.item.to_dask()

Now we can visualise and inspect data with XrViz.

XrViz Dashboard

from xrviz.dashboard import Dashboarddash = Dashboard(data)
dash.panel

This is all you need to visualise any xarray data with XrViz!

New features added in XrViz are:

1. Style Panel

It provides the user with options to change properties such as height , width , cmap and color_scale to customise the graph.

2. Projection Panel

This panel allows the user to project the data on a map or Cartopy projection, in case it is geographic. This will be immensely useful for Earth Science researchers in analysis of geographical data. It provides options to choose basemap , crs , projection , features and other parameter inputs to modify accordingly.

3. Series extraction

This panel allows the user to extract a series along a third dimension upon selection in fields panel. The user can click on the main 2D graphical output, and have a graph of a third dimension at that point appear in a separate, adjacent panel. Each click will produce a marker, and the line in the graph will have the same colour as that marker. Several lines can be over-plotted, and the dimension to use for the plotting will be chosen in the “fields” section of the interface. Hovering over the line shows more information about that series.

Live Example

Please have a look at these dashboards deployed on binder.

  1. Intake and XrViz Dashboard
  2. Explore-HRRR-with-XrViz

This is how the interface looks now:

Discussions

If you have any ideas or questions regarding this project please feel free to discuss in our Gitter channel or submit a PR on GitHub.

Harman Deep Singh

Written by

Computer Science Student, Interested in Data Visualisation and Deep Learning | GSoC’19 @ESIP

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