Data visualization with tableau

course link: https://www.udacity.com/course/data-visualization-in-tableau--ud1006

book: the visual display of quantitative information.

visual encoding:

1. lines for trends, if no trend, use bars to compare group
2. histogram is a bar plot where a variable is binned into ranges
3. violin plot = box plot + kernel density estimation

char suggestion:

Tableau

Tableau is an interactive data visualization software for business intelligence. It is founded in 2003, as a result, to commercialize research at Stanford University’s CS department.

free version: https://public.tableau.com/s/

official training: https://www.tableau.com/learn/training

subscription price ranges from $35 to 70 per month.

It supports excel, text, JSON and statistical files.

Union vs Join

https://onlinehelp.tableau.com/current/pro/desktop/en-us/joining_tables.html

	Union	Join
operation	drag right below 1st table	drag elsewhere
column change	combine without merge	merge common fields
	more verbose	more concise

default join is inner join, which only combines data with a common value. Left join will have all the original data.

Dimensions vs Measures

Dimensions are more discrete values, like category, city, date, region.

Measures are more continuous values, like profit, quantity, height, age.

There are some overlaps.

3 working modes

1. sheet. drag x value to “Columns”, y value to “Rows”, label value to “Marks” or “Filters”
2. dashboard: drop multiple sheets together to address something
3. story: ppt-like experience to tell a story.

Remark

This is an elegant and powerful software. It seems to have a web-based functionality in mind. In my public version, I can’t output the graph but can only store everything in its cloud. Maybe it is because the mouse-over feature is data encoded so the stand-alone graph will lose its spotlight.

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