 # ROUND_TO function: rounds double/float to fixed number of decimal places

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#### Details

• New Feature
• Status: Closed
• Minor
• Resolution: Fixed
• 0.12.0
• None
• Patch Available
• Hide
The ROUND_TO(val, digits[, mode]) function accepts a single float or double value, along with an integer number of digits, and returns the value to that number of decimal places. For example, ROUND_TO(3.14159f, 3) returns 3.142f (a float); ROUND_TO(3.14159d, 0) returns 3.0d (a double); and ROUND_TO(1234.56d, -2) returns 1200d. The optional third argument controls the rounding mode; see the documentation.
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The ROUND_TO(val, digits[, mode]) function accepts a single float or double value, along with an integer number of digits, and returns the value to that number of decimal places. For example, ROUND_TO(3.14159f, 3) returns 3.142f (a float); ROUND_TO(3.14159d, 0) returns 3.0d (a double); and ROUND_TO(1234.56d, -2) returns 1200d. The optional third argument controls the rounding mode; see the documentation.

#### Description

The too-often used trick of rounding to a fixed number of decimal places by writing '1000 * Math.round(num / 1000.0)' is not only unsightly, it's numerically imprecise (http://stackoverflow.com/a/12684082/41857). The attached patch adds a function to do this.

ROUND_TO(val, digits) accepts a single float or double value, along with an integer number of digits, and returns the value to that number of decimal places

Examples:

```ROUND_TO(3.14159f, 3) -- returns a float 3.142
ROUND_TO(3.14159d, 0) -- returns a double 3.0.
```

I also added unit tests for ROUND – there were none before that I could find.

I don't know how to write a unit test that the schema correctly routes to FloatRoundTo and DoubleRoundTo – if the ones I provided are insufficient please point me to a simple example to emulate.

#### People Flip Kromer Flip Kromer