Contents:
Each argument can be a Decimal or Integer literal or a reference to a column containing numeric values.
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:
pow(10,3)
Output: Returns the value of 10 3, which is 1000.
Column reference example:
pow(MyValue,2)
Output: Returns the value of the MyValue column raised to the power of 2 (squared).
Syntax and Arguments
pow(base_numeric_value, exp_numeric_value)
| Argument | Required? | Data Type | Description |
|---|---|---|---|
| base_numeric_value | Y | string, decimal, or integer | Name of column or Decimal or Integer literal that is the base value to be raised to the power of the second argument |
| exp_numeric_value | Y | string, decimal, or integer | Name of column or Decimal or Integer literal that is the power to which to raise the base value |
For more information on syntax standards, see Language Documentation Syntax Notes.
base_numeric_value
Name of the column or numeric literal whose values are used as the bases for the exponential computation.
- Missing input values generate missing results.
- Literal numeric values should not be quoted.
- Multiple columns and wildcards are not supported.
Usage Notes:
| Required? | Data Type | Example Value |
|---|---|---|
| Yes | String (column reference) or Integer or Decimal literal | 2.3 |
exp_numeric_value
Name of the column or numeric literal whose values are used as the power to which the base-numeric value is raised.
- Missing input values generate missing results.
- Literal numeric values should not be quoted.
- Multiple columns and wildcards are not supported.
Usage Notes:
| Required? | Data Type | Example Value |
|---|---|---|
| Yes | String (column reference) or Integer or Decimal literal | 5 |
Tip: For additional examples, see Common Tasks.
Examples
Example - Exponential functions
Functions:
| Item | Description |
|---|---|
| EXP Function | Computes the value of e raised to the specified power. The value can be a Decimal or Integer literal or a reference to a column containing numeric values. |
| LN Function | Computes the natural logarithm of an input value. The value can be a Decimal or Integer literal or a reference to a column containing numeric values. |
| LOG Function | Computes the logarithm of the first argument with a base of the second argument. |
| POW Function | Computes the value of the first argument raised to the value of the second argument. |
Source:
| rowNum | X |
|---|---|
| 1 | -2 |
| 2 | 1 |
| 3 | 0 |
| 4 | 1 |
| 5 | 2 |
| 6 | 3 |
| 7 | 4 |
| 8 | 5 |
Transformation:
| Transformation Name | New formula |
|---|---|
| Parameter: Formula type | Single row formula |
| Parameter: Formula | EXP (X) |
| Parameter: New column name | 'expX' |
| Transformation Name | New formula |
|---|---|
| Parameter: Formula type | Single row formula |
| Parameter: Formula | LN (expX) |
| Parameter: New column name | 'ln_expX' |
| Transformation Name | New formula |
|---|---|
| Parameter: Formula type | Single row formula |
| Parameter: Formula | LOG (X) |
| Parameter: New column name | 'logX' |
| Transformation Name | New formula |
|---|---|
| Parameter: Formula type | Single row formula |
| Parameter: Formula | POW (10,logX) |
| Parameter: New column name | 'pow_logX' |
Results:
In the following, (null value) indicates that a null value is generated for the computation.
| rowNum | X | expX | ln_expX | logX | pow_logX |
|---|---|---|---|---|---|
| 1 | -2 | 0.1353352832366127 | -2 | (null value) | (null value) |
| 2 | -1 | 0.1353352832366127 | -0.9999999999999998 | (null value) | (null value) |
| 3 | 0 | 1 | 0 | (null value) | 0 |
| 4 | 1 | 2.718281828459045 | 1 | 0 | 1 |
| 5 | 2 | 7.3890560989306495 | 2 | 0.30102999566398114 | 1.9999999999999998 |
| 6 | 3 | 20.085536923187668 | 3 | 0.47712125471966244 | 3 |
| 7 | 4 | 54.59815003314423 | 4 | 0.6020599913279623 | 3.999999999999999 |
| 8 | 5 | 148.41315910257657 | 5 | 0.6989700043360187 | 4.999999999999999 |
Example - Pythagorean Theorem
Functions:
| Item | Description |
|---|---|
| POW Function | Computes the value of the first argument raised to the value of the second argument. |
| SQRT Function | 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. |
Source:
The dataset below contains values for x and y:
| X | Y |
|---|---|
| 3 | 4 |
| 4 | 9 |
| 8 | 10 |
| 30 | 40 |
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:
| X | Y | Z |
|---|---|---|
| 3 | 4 | 5 |
| 4 | 9 | 9.848857801796104 |
| 8 | 10 | 12.806248474865697 |
| 30 | 40 | 50 |
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