# PI Function

The PI function generates the value of pi to 15 decimal places: 3.1415926535897932.

This function uses no parameters. Generated values are of Decimal type and have fifteen digits of precision after the decimal point. If you want to see a fewer number of digits in the generated value, you might need to apply a different number format or using the ROUND function.

Wrangle vs. SQL: This function is part of Wrangle, a proprietary data transformation language. Wrangle is not SQL. For more information, see Wrangle Language.

## Basic Usage

pi()

Output: Returns the value of pi.

## Syntax and Arguments

There are no arguments for this function.

## Examples

Astuce

### Example - pi column

In the following example, the source is simply the source column, and the pi column is generated by the PI function:

 Transformation Name New formula Single row formula pi() 'pi'

source

pi

A

3.1415926535897932

B

3.1415926535897932

C

3.1415926535897932

D

3.1415926535897932

### Example - RANDBETWEEN, PI, and TRUNC functions

This example illustrates how you can apply functions to generate random numeric data in your dataset.

Functions:

Item

Description

RANDBETWEEN Function

Generates a random integer between a low and a high number. Two inputs may be Integer or Decimal types, functions returning these types, or column references.

PI Function

The PI function generates the value of pi to 15 decimal places: 3.1415926535897932.

ROUND Function

Rounds input value to the nearest integer. Input can be an Integer, a Decimal, a column reference, or an expression. Optional second argument can be used to specify the number of digits to which to round.

TRUNC Function

Removes all digits to the right of the decimal point for any value. Optionally, you can specify the number of digits to which to round. Input can be an Integer, a Decimal, a column reference, or an expression.

POW Function

Computes the value of the first argument raised to the value of the second argument.

Source:

In the following example, a company produces 10 circular parts, the size of which is measured in each product's radius in inches.

prodId

p001

1

p002

2

p003

3

p004

4

p005

5

p006

6

p007

7

p008

8

p009

9

p010

10

Based on the above data, the company wants to generate some additional sizing information for these circular parts, including the generation of two points along each part's circumference where quality stress tests can be applied.

Transformation:

To begin, you can use the following steps to generate the area and circumference for each product, rounded to three decimal points:

 Transformation Name New formula Single row formula ROUND(PI() * (POW(radius_in, 2)), 3) 'area_sqin'
 Transformation Name New formula Single row formula ROUND(PI() * (2 * radius_in), 3) 'circumference_in'

For quality purposes, the company needs two tests points along the circumference, which are generated by calculating two separate random locations along the circumference. Since the RANDBETWEEN function only calculates using Integer values, you must first truncate the values from circumference_in:

 Transformation Name New formula Single row formula TRUNC(circumference_in) 'trunc_circumference_in'

Then, you can calculate the random points using the following:

 Transformation Name New formula Single row formula RANDBETWEEN(0, trunc_circumference_in) 'testPt01_in'
 Transformation Name New formula Single row formula RANDBETWEEN(0, trunc_circumference_in) 'testPt02_in'

Results:

After the trunc_circumference_in column is dropped, the data should look similar to the following:

prodId

area_sq_in

circumference_in

testPt01_in

testPt02_in

p001

1

3.142

6.283

5

5

p002

2

12.566

12.566

3

3

p003

3

28.274

18.850

13

13

p004

4

50.265

25.133

24

24

p005

5

78.540

31.416

0

0

p006

6

113.097

37.699

15

15

p007

7

153.938

43.982

11

11

p008

8

201.062

50.265

1

1

p009

9

254.469

56.549

29

29

p010

10

314.159

62.832

21

21