| Excerpt |
|---|
Computes the positive or negative sign of a given numeric value. The value can be a Decimal or Integer literal, a function returning Decimal or Integer, or a reference to a column containing numeric values. |
- For positive values, this function returns
1. - For negative values, this function returns
-1. - For the value
0, this function returns 0.
Column reference example:
| D code |
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derive type:single value:SIGN(MyInteger) as:'sign_MyInteger' |
Output: Generates the new sign_MyInteger column containing the absolute value of each value found in the MyInteger column.
Numeric literal example:
| D code |
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delete row:(SIGN(MyInteger) == -1) |
Output: Deletes all rows from the dataset in which the sign of the entry in the MyInteger column is -1. This transform remove all rows contain negative values in the MyInteger column.
| D code |
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derive type:single value:SIGN(numeric_value) |
| Argument | Required? | Data Type | Description |
|---|
| numeric_value | Y | Decimal or Integer | Decimal or Integer literal, function returning Decimal or Integer, or name of column to apply to the function |
numeric_value
Numeric literal, function returning numeric literal, or name of the column containg values the sign of which are to be computed.
- Missing input values generate missing results.
- Literal numeric values should not be quoted. Quoted values are treated as strings.
- Multiple columns and wildcards are not supported.
| Required? | Data Type | Example Value |
|---|
| Yes | String (column reference) or Integer or Decimal value | -10.5 |
Example - Basic SIGN function
Source:
Your source data looks like the following, which measures coordinate distances from a fixed point on a grid:
| X | Y |
|---|
| -2 | 4 |
| -6.2 | -2 |
| 0 | -4.2 |
| 4 | 4 |
| 15 | -0.05 |
Transform:
You can use the following transform to derive the sign values of these columns:
| D code |
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derive type:single value: SIGN(X) as: 'signX' |
| D code |
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derive type:single value: SIGN(Y) as: 'signY' |
Using these two columns, you can assign each set of coordinates into a quadrant:
| D code |
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case cases: [(signX == 1) && (signY == -1),'lower-right'],[(signX == 1) && (signY == 1),'upper-right'],[(signX == -1) && (signY == -1),'lower-left'],[(signX == -1) && (signY == 1),'upper-left'] default: 'line' as: 'quadrant' |
Results:| X | Y | signX | signY | quadrant |
|---|
| -2 | 4 | -1 | 1 | upper-left |
| -6.2 | -2 | -1 | -1 | lower-left |
| 0 | -4.2 | 0 | -1 | line |
| 4 | 4 | 1 | 1 | upper-right |
| 15 | -0.05 | 1 | -1 | lower-right |
