In this blog, I am going to show you how to make the radial column chart and demonstrate this using the sample Super Store data set
Data Densification
Data densification is a way to increase the number of observations in the dataset. For example, you need to perform data densification if you want to show any curved path, like flight paths on a map, Sankey diagrams, radial charts, etc. In this blog, I will create a densification table and link it back to the orders table by the relationship to achieve data densification. The data model setup as below:
Making the Radial Column Chart
Step 1: Create three calculated fields named “ Order Date(Month)” and “Order Date(Year) and Index.
(1) Order Date(Month):
DATETRUNC(‘month’,[Order Date])
(2) Order Date(Year):
YEAR([Order Date])
(3)Index:
INDEX()-1
Step2: Create the following calculated fields
(1) X:
IF MAX([Path])=1
THEN SIN(RADIANS([Index]))
ELSE SIN(RADIANS([Index]))*2
END
(2) Y:
IF MAX([Path])=1
THEN COS(RADIANS([Index]))
ELSE COS(RADIANS([Index]))*2
END
(3) TC_Year
WINDOW_MAX(MAX([Order Date(Year)]))
Step3: I’ll drag X into the column and take Y in the row after creating the above-calculated field. Also, add Order Date(Month) into the detail mask, and make sure that Order Date(Month) is in a discreet place
Step 4: Change the chart to a line chart and drag the Path field into the Path mask. As you can see, a line has been drawn based on the position. Right-click on X and Y, then go to “Compute Using” and select Date of “Order (Month)”
Step 5: Now, I will drag the TC_Year into the Color mask, and you can see the basis of the data visualization
Step 6: I will apply the sales data to the visualization by constructing the following calculated fields:
(1)TC_Sales:
WINDOW_SUM(SUM([Sales]))
(2)TC_Total Sales:
WINDOW_SUM(SUM([Sales]))
(3)TC_Total Sales:
WINDOW_SUM(SUM([Sales]))
Step 7: Let’s modify X, Y again by multiplying TC_Distance
Modify X:
IF MAX([Path])=1
THEN SIN(RADIANS([Index]))
ELSE SIN(RADIANS([Index]))* (1+[TC_Distance])
END
Modify Y:
IF MAX([Path])=1
THEN COS(RADIANS([Index]))
ELSE COS(RADIANS([Index]))* (1+[TC_Distance])
END
Step8: To plot the sales data in the chart, I need to make the following changes to the X and Y table calculations:
Step9: The final step is to add space between the lines to make up the whole circle. Then, I’ll make a calculated field called “TC Space” and modify the X and Y values again.
TC_Space:
(360-(360/WINDOW_MAX([Index])))/WINDOW_MAX([Index])
Modify X:
IF MAX([Path])=1
THEN SIN(RADIANS([Index] *[TC_Space]))
ELSE SIN(RADIANS([Index] *[TC_Space]))*(1+[TC_Distance])
END
Modify Y:
IF MAX([Path])=1
THEN COS(RADIANS([Index] *[TC_Space]))
ELSE COS(RADIANS([Index] *[TC_Space]))*(1+[TC_Distance])
END
Ok, you’ve now learned how to create a radial column chart. I hope you can make your own by following the above steps.
Tableau Public link: