Overview of Tableau
Introduction
Tableau is a business intelligence (BI) tool that focuses on data visualization, dashboarding, and data discovery. It connects to a wide range of data sources and enables users to gain valuable insights, show trends quickly, and create reports. In Tableau, charts are vital in transforming raw data into meaningful insights.
How is Tableau used in Data Analytics?
1. Connecting your data using tableau
Tableau is capable of connecting with a wide range of data sources. It can connect to files present in your system, such as Microsoft Excel, text files, JSON, PDF, etc. Your data can come from a PDF or text file but using a Microsoft Excel file offers the smoothest data transition. Tableau creates a direct connection to the file. There is no importing or storing of the data, meaning that any changes you make to the spreadsheet will be directly tied to your Workbook. Select the Spreadsheet you want your data to be sourced from and drag it into your Workbook.
The following is an example of importing an excel file to Tableau Desktop. Under Connect, click on Microsoft Excel. Locate the Excel file present in your system, which will export the dataset into Tableau. As you can see below, we have imported the Sample - Superstore dataset. Now, drag the required sheets under the “Drag tables here” space.
Once you have connected to your data and have selected the spreadsheet you want to work with, it's time to create your first Worksheet in the workspace.
2. Tableau Desktop Interface
Tableau Desktop’s interface, or the workspace, consists of menus, a toolbar, cards, shelves, data pane, different sheets for creating reports, dashboards, and stories.
3. Dimensions and Measures in Tableau
Once you load a dataset, Tableau automatically divides the data into dimensions and measures. You can see this in the workspace area under the data pane.
Dimensions are usually categorical fields that cannot be aggregated, while measures are numerical fields that can be measured, aggregated, or manipulated.
Dimensions are marked in blue, while measures are marked in green.
4. How to Create a Tableau Visualization to Analyze Data
Since Tableau is a drag-and-drop application, go ahead and drag whichever data field you want to be represented in the Column. Now you can format to show specific data.
Next, take a corresponding value and drag it over to the Rows. You will now be able to visualize and interact with the data you have created.
If you would like to make the data set more interactive for an end-user, add some data sets to the Filter panel and edit what you would want to see. Try and change the Color, Size, and Label in the Marks panel as well!
5. Creating visualizations using charts
A Chart is a representation of data in the form of a graph, diagram, map, or tabular format and helps you to identify which one works better for your data.
Tableau Charts are the visual medium to analyze and communicate data effectively. Charts display many forms of analysis in a visual format: Comparison, Relationship, distribution and Composition.
Consider the most common charts: Scatterplots, Bar charts, Line Graphs, Pie Charts, Tree Maps, Map Charts etc. We can see some of the charts below.
Simple dual axis chart
A dual-axis chart will analyze sales and profits by order month. Drag the order date field on to columns and profit field on the right corner where you see a green rectangle. Synchronize the profit axis and change sales to bars.
Bar Chart
The horizontal bar chart below shows sales of different subcategories of products with the color of the bars indicating the profit. Sort the sales axis in descending order and change the color of the bars using a different palette.
Tree map
A straightforward rectangular chart, Tree Map is representing data in nested rectangles. Here, the dimensions are defining the structure of rectangles. Moreover, this helps relate varying segments of the data to the whole of it.
Map Chart
Maps in Tableau help users visualize geographic data and analyze certain measure values. The following is an example of analyzing sales and profits across different states in the US. Drag the country field on to the view and expand it to see all states.
States marked in green made the highest profit, while those marked in orange made the least amount of profit. This shows that California has the highest sales and profit, followed by New York. It also reveals that Texas made a decent amount of sales, but overall, made the least amount of profit.
You can also change the map into a filled map by selecting “map” from the marks card.
6. Building Dashboards Using Tableau
A Tableau dashboard is a collection of several charts and graphs from different worksheets. It provides a single view for analyzing the entire business dataset.
To create a dashboard in Tableau, click on the “New Dashboard” tab at the bottom.
Drag all desired worksheets to the dashboard view and adjust all the sheets so that everything looks clean and organized.
As you can see, we have four sheets placed on the dashboard. There is a bar chart, a dual axis chart, a map, and a tree map that provides a clear picture of sales and profit across different regions, states, order dates, categories and subcategories of products.
7. Creating a Story
A story is a sheet that contains a sequence of worksheets or dashboards that work together to convey information. You can create stories to show how facts are connected, provide context, demonstrate how decisions relate to outcomes and save your work in Tableau public.
Saving the work
Tableau Desktop
To save a Tableau workbook locally, Select File > Save. Specify the workbook file name in the Save As dialog box Tableau by default saves the file with the .twb extension.
Tableau Public
With Tableau Public all the views and data are made public and anybody on the internet has access to it. Select Server > Tableau Public > Save to Tableau Public and enter the credentials.
Conclusion
We explored what tableau is exactly, how to download it to file types to data types and so much more and how to create interactive reports and dashboards using business data, which derives meaningful insights for making important business decisions by analyzing data. So, with experimentation and practice, tableau becomes a lot more familiar and will unleash amazing features to help us analyze present data.