Public Tableau

Tableau Products:

The Picture Superiority Effect refers to the phenomenon when a person is able to recall visual content better than content presented only as text.

Tableau Public:

limitations :
- data become public and can be downloaded by anyone
- visualizations cannot be save locally (if you do not have internet you can not save)
- There are fewer ways to connect data to Tableau Public. (Excel, text)
available for windows and mac
installation :
- download from public.tableau.com/s/
- install and open
- click on open from Tableau Public to create an account
replicate visualization Examples
- download from https://public.tableau.com/profile/govind.acharya#!/vizhome/Lesson1-4firstvisualizationdata/Sheet1. To save a visualization file on Tableau Public, visualized data must be present within the file. For this, when we open the file, we had country field already in it.
- download https://public.tableau.com/s/gallery/mapping-1854-cholera-outbreak tableau workbook classeur). It is not statistically very difficult but it has a historical impact and story telling:
  - hypothesis : cholera is not transmitted through the air as was widely assumed in The 1800s

Survey of tableau workspace:

To view the data underlying a visualization , click on the icon next to the text, “Dimensions” in the data window.
To view a Varibale summary (typee, range),right click to check describe,then load
Fields:
- Dimensions: used to categorize the datas
- Measures : help determine the scale of the categories
Signs:
- '#' : the data is a number,
- 'abc': text data
- globe: geographical data
- calendar : dates
New work sheets unlimited
a dimension and a measure are not interpreted the same when put as rows and columns respectively. A dimension is kept unchanged and a measure is averaged
the swap button allows to easily fix how the visualization is displayed
put a dimension in marks shelf
right click on dimension to show filter
the "show me" botton : different visualization types
click on tableau symbol to connect to a file
TO MERGE worksheets create new dashboard

types :
- local file
  - first row contains varibles names
  - remove any total data
- server
  - OData : An OData connection can access data from traditional websites, content management systems, text files , relational databases
tableau makes joins on selected worksheets automatically based on a common column
tableau makes unions of datasets (ADDING LINES)
when to use a Tableau Data Extract (TDE) vs. a live connection:
- http://drawingwithnumbers.artisart.org/tde-or-live-when-to-use-tableau-data-extracts/
- Using a live connection is better because extracting data adds another step to the data delivery chain. However there are many situations where that isn’t a workable solution, so Tableau has created Tableau Data Extracts to support situations where a live connection to the source is not possible for a production system, too slow, unable to handle volumes, complexity, exposing too much volume, not supporting certain calculations, merge file-bases

Overview Reference :