Lab | Tableau - Manipulating data from multiple sources

For this lab, we will be using the dataset in the Customer Analysis Business Case. This dataset can be found in files_for_lab folder.

In this lab we are going to take a look at the pdf file, files_for_lab/nz_water_water_resources.pdf, but we will take a look at the other two tables, ie. page 14 table 2 and page 14 table 3.

Context

As discussed during the last lesson, these are another couple of ways in which Tableau reads the data from the table on page 14 in the PDF file.

• page 14 table 2 represents one half of the information
• page 14 table 3 represents the other half of the information

Instructions

1. Create a union between the two tables.
2. Hide the column Table Name.
3. Clean the data.

Hints:

• You will see that the information from the PDF file's column 1 is split into two different columns when the data was imported using Tableau. Select the two columns and then use the option merge mismatch fields to combine those two columns.

• Rename the columns appropriately (rename the headers as years, as given in the PDF)

• Unlike the previous case, here we will keep all the sources except for the totals (ie. filter out the total and keep the rest)

• Select the data and create a pivot as shown below

• Rename the columns as source, year, and million cubic meters.

• As you would notice, there would still be some null values in the column million cubic meters. Remove those nulls.

• Convert the type of column years to the Date type.

• Convert the type of column million cubic meters to whole numbers.

• There would still be some issues with the names of the sources in the first column. Select column drop down and choose Aliases.

  • As you would see from the PDF file, hydroelectricity should be abstraction for hydroelectricity; and generation should be discharge from hydroelectricity generation.
  • Go ahead and change those aliases
  • Change dimensions to measures wherever necessary.
  • Now go to the sheet, and create a plot and show the top 4 sources of generation. The final plot should look like this. Note here we have used a filter in the sheet to remove the column with discharge.