Page tree

Trifacta Dataprep


Contents:

On April 28, 2021, Google is changing the required permissions for attaching IAM roles to service accounts. If you are using IAM roles for your Google service accounts, please see Changes to User Management.

   

Computes the square root of the input parameter.  Input value can be a Decimal or Integer literal or a reference to a column containing numeric values. All generated values are non-negative.

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

Numeric literal example:

sqrt(25)

Output: Returns the square root of 25, which is 5.

Column reference example:

sqrt(MyValue)

Output: Returns the square root of the values of the MyValue column. 

Syntax and Arguments

sqrt(numeric_value)


ArgumentRequired?Data TypeDescription
numeric_valueYstring, decimal, or integerName of column or Decimal or Integer literal to apply to the function

For more information on syntax standards, see Language Documentation Syntax Notes.

numeric_value

Name of the column or numeric literal whose values are used to compute the square root.

NOTE: Negative input values generate null output values.

  • Missing input values generate missing results.
  • Literal numeric values should not be quoted. 
  • Multiple columns and wildcards are not supported.

Usage Notes:

Required?Data TypeExample Value
YesString (column reference) or Integer or Decimal literal25

Examples

Tip: For additional examples, see Common Tasks.

Example - Pythagorean Theorem

The following example demonstrates how the POW and SQRT functions work together to compute the hypotenuse of a right triangle using the Pythagorean theorem.
  • POW - X Y . In this case, 10 to the power of the previous one. See POW Function
  • SQRT - computes the square root of the input value. See SQRT Function.

The Pythagorean theorem states that in a right triangle the length of each side (x,y) and of the hypotenuse (z) can be represented as the following:

z2 = x 2 + y 2  

Therefore, the length of z can be expressed as the following:

z = sqrt(x 2  + y 2 )

Source:

The dataset below contains values for x and y:

 

XY
34
49
810
3040

Transformation:

You can use the following transformation to generate values for z2

NOTE: Do not add this step to your recipe right now.

Transformation Name New formula
Parameter: Formula type Single row formula
Parameter: Formula (POW(x,2) + POW(y,2))
Parameter: New column name 'Z'

You can see how column Z is generated as the sum of squares of the other two columns, which yields z2.

Now, edit the transformation to wrap the value computation in a SQRT function. This step is done to compute the value for z, which is the distance between the two points based on the Pythagorean theorem.

Transformation Name New formula
Parameter: Formula type Single row formula
Parameter: Formula SQRT((POW(x,2) + POW(y,2)))
Parameter: New column name 'Z'

Results:

XYZ
345
499.848857801796104
81012.806248474865697
304050

This page has no comments.