Dashboarding with Vega-Lite and Mondrian

Vega / Vega-Lite / Altair Seattle Meetup - May 2, 2018

Scott Came

Principal

Cascadia Analytics LLC

Big Picture

Mondrian OLAP Library/Schema

SAML Security

CSV

Loading Process

Relational

Database

Dashboard web application

Java EE

jQuery

Bootstrap

Saiku BI Community

Visualization

Definitions

Vega / Vega-Lite

Requirements:

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• Open Source
• Extensible
• Cloud deployment (AWS)
• Ingest data from CSV
• Simple/intuitive dashboard UI
• “Power user” query UI

Dragula.js

Spring Boot

OJBC mondrian-rest

Demo

docker run -d --name dashcard -p 58081:80 scottcame/dashcard

http://localhost:58081/dashcard/demo.html

Code Walk Through

https://github.com/scottcame/dashcard

A Challenge

• mondrian-rest serves up OLAP results in JSON that Vega-Lite expects ( { values: [] } )

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• However, in the real world (i.e., sufficiently complex queries), manipulation is required before setting the data property on the Vega-Lite specification

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• Example: benchmarking (comparing measures in the leaves to the same measure at a rollup level)

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• Idea: a Javascript library for manipulation (what R folks call “tidying”) of the values “data frame”. Example functions could include:

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• mutate(newvar=f(currentVar))
• join(values1, values2, by=[by1, by2, ...])
• gather(keyColumn, valueColumn, gatherColumns=[c1, c2, …])
• spread(keyColumn, valueColumn)

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• Thoughts? Does a library exist to do this already?

Resources

scott@cascadia-analytics.com https://github.com/scottcame

@scottcame / @cascadialytics http://www.cascadia-analytics.com

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Me: