I have decided to experiment sin and cos functions in Tableau and play a bit with them.

First of all, a bit of context of what I have done and some maths references about the circle equation & formulas.

STEP 1 – “HOME MADE” EXCEL WORKSHEET

I have built a simple excel sheet with

  • Path: basically an ID per row
  • Alpha: angle, calculated with excel using the pi() function (for example, type pi()*1/4 to get an angle of 45 degrees)

alpha_path

 

STEP 2 – MATHS BEHIND THE SCENE

Consider the case of a circle with radius r=1 and center in C(x_0=0,y_0=0). After connecting Tableau to this dataset, create two calculated fields, X and Y:

X

Y

Why these formulas?

A bit of mathematics about circle: the general formulas to calculate x and y are the following

  • x=x_0+r*cos(alpha)
  • y=y_0+r*sin(alpha)

In our case, the formulas will be simply (because we are supposing that r=1, C(0,0)):

  • x=cos(alpha)
  • y=sin(alpha).

 

STEP 3 – TABLEAU VIZ

And now, what can you viz?

Drag X and Y into Columns and Rows (and if you want the angle Alpha into size), you will get:

CIRCLE_1

Now, if you switch to “line” in the mark field and add path to path, you will get an Octagon:

Octagon_2

I hope you enjoy it.

A presto!