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.
See NUMFORMAT Function.
See 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
Tip
For additional examples, see Common Tasks.
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 |
|
|---|---|
Parameter: Formula type | Single row formula |
Parameter: Formula | pi() |
Parameter: New column name | '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 the following functions to generate new and random data in your dataset:
RANDBETWEEN- Generate a random Integer value between two specified Integers. See RANDBETWEEN Function.PI- Generate the value of pi to 15 decimal points. See PI Function.ROUND- Round a decimal value to the nearest Integer or to a specified number of digits. See ROUND Function.TRUNC- Round a value down to the nearest Integer value. See TRUNC Function.
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 | radius_in |
|---|---|
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 |
|
|---|---|
Parameter: Formula type | Single row formula |
Parameter: Formula | ROUND(PI() * (POW(radius_in, 2)), 3) |
Parameter: New column name | 'area_sqin' |
Transformation Name |
|
|---|---|
Parameter: Formula type | Single row formula |
Parameter: Formula | ROUND(PI() * (2 * radius_in), 3) |
Parameter: New column name | '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 |
|
|---|---|
Parameter: Formula type | Single row formula |
Parameter: Formula | TRUNC(circumference_in) |
Parameter: New column name | 'trunc_circumference_in' |
Then, you can calculate the random points using the following:
Transformation Name |
|
|---|---|
Parameter: Formula type | Single row formula |
Parameter: Formula | RANDBETWEEN(0, trunc_circumference_in) |
Parameter: New column name | 'testPt01_in' |
Transformation Name |
|
|---|---|
Parameter: Formula type | Single row formula |
Parameter: Formula | RANDBETWEEN(0, trunc_circumference_in) |
Parameter: New column name | 'testPt02_in' |
Results:
After the trunc_circumference_in column is dropped, the data should look similar to the following:
prodId | radius_in | 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 |