Tableau Basic Module
Module: Calculations
This class demonstration introduces the ways in which the formatting of a worksheet can be customized in Tableau. Students are encouraged to follow along and/or take notes on the provided Student Handout.
This topic uses Sales_Quotas and Telecommunications.
Similar to formulas in Excel, calculations allow you to manipulate your data in any number of ways. Creating a calculated field is as easy as right clicking in the data window and selecting Create Calculated Field.
Data Validation - Nulls to Zeroes
FILE to use: Sales_Quotas.twbx
A common issue with real-world datasets is the presence of null values, or blanks, in the data. This can make data analysis challenging and frustrating (as you may know, some statistical techniques will not work at all if there are nulls in the data). Luckily, with Calculations we can easily remove Nulls from our data:
Now open Sales_Quotas. In this dataset, we have sales quotas for some, but not all of our countries.
Double-click Country to get a dot everywhere we do business. I want to see how we are doing relative to quotas everywhere.
But I have included an issue in the data that needs to be fixed: Right-click somewhere in the map and view data. There are several nulls for Quotas.
Our main goal is to compare the sales to their quotas, but we cannot compare a number to a null. We need to convert our nulls to zeros so that we can do a comparison.
• right-click in the data window and select create calculated field.
• Name it "Corrected Quota".
o And type ZN(
• The ZN function returns a zero wherever there is a null. We can think of this function as asking "Is there a quota for this country? If not, give it a zero."
• Drag out Quota, and close the parentheses.
• Now if we replace Quota with our Corrected Quotas we see zeros in lieu of the blanks we had before.
• Click OK
o NOTE: in this case the Null values had a logical interpretation as zeros. But if it is truly missing data, and we want to exclude the rows with Nulls from our analysis, we can use a Data Source Filter:
i. Right click on the data source and select "Edit Data Source Filters"
ii. Click Add and select the field that contains the Nulls
iii. Tick Null and select Exclude
Now we can visualize how different our sales are from our quotas. Again, we can right-click and create a Calculated Field
o We'll call this our "QuotaCompare"
o SUM(Sales)-SUM(Corrected Quota)
• Double-clickQuotaCompare to bring it into the view
• Taiwan, Portugal, and Austria look pretty good. To get more data into the viz, add Corrected Quota to the Tooltip. Why do these 3 countries look so strong?
Calculated Fields
FILE to use: Telecommunications.twbx
Your task: recreate the dashboard depicted below exactly
Attachment:- data validation.rar