# decimal

package
Version: v0.0.0-...-a3ba52b Latest Latest

Go to latest
Published: Jul 23, 2016 License: Apache-2.0

## Documentation ¶

### Constants ¶

View Source
`const Precision = 16`

Precision defines the minimum precision all inexact decimal calculations should attempt to achieve.

### Variables ¶

This section is empty.

### Functions ¶

#### func Cbrt ¶

`func Cbrt(z, x *inf.Dec, s inf.Scale) *inf.Dec`

Cbrt calculates the cube root of x to the specified scale and stores the result in z, which is also the return value.

The cube root calculation is implemented using Newton-Raphson method. We start with an initial estimate for cbrt(d), and then iterate:

```x_{n+1} = 1/3 * ( 2 * x_n + (d / x_n / x_n) ).
```

#### func Exp ¶

`func Exp(z, n *inf.Dec, s inf.Scale) *inf.Dec`

Exp computes (e^n) (where n = a*b with a being an integer and b < 1) to the specified scale and stores the result in z, which is also the return value.

#### func Float64FromDec ¶

`func Float64FromDec(dec *inf.Dec) (float64, error)`

Float64FromDec converts a decimal to a float64 value, returning the value and any error that occurred. This converson exposes a possible loss of information.

#### func Log ¶

`func Log(z *inf.Dec, x *inf.Dec, s inf.Scale) *inf.Dec`

Log computes the natural log of x using the Maclaurin series for log(1-x) to the specified scale and stores the result in z, which is also the return value. The function will panic if x is a negative number.

#### func Log10 ¶

`func Log10(z *inf.Dec, x *inf.Dec, s inf.Scale) *inf.Dec`

Log10 computes the log of x with base 10 to the specified scale and stores the result in z, which is also the return value. The function will panic if x is a negative number.

#### func LogN ¶

`func LogN(z *inf.Dec, x *inf.Dec, n *inf.Dec, s inf.Scale) *inf.Dec`

LogN computes the log of x with base n to the specified scale and stores the result in z, which is also the return value. The function will panic if x is a negative number or if n is a negative number.

#### func Mod ¶

`func Mod(z, x, y *inf.Dec) *inf.Dec`

Mod performs the modulo arithmatic x % y and stores the result in z, which is also the return value. It is valid for z to be nil, in which case it will be allocated internally. Mod will panic if the y is zero.

The modulo calculation is implemented using the algorithm:

```x % y = x - (y * ⌊x / y⌋).
```

#### func NewDecFromFloat ¶

`func NewDecFromFloat(f float64) *inf.Dec`

NewDecFromFloat allocates and returns a new Dec set to the given float64 value. The function will panic if the float is NaN or ±Inf.

#### func Pow ¶

`func Pow(z, x, y *inf.Dec, s inf.Scale) *inf.Dec`

Pow computes (x^y) as e^(y ln x) to the specified scale and stores the result in z, which is also the return value. If y is not an integer and x is negative nil is returned.

#### func PowerOfTenDec ¶

`func PowerOfTenDec(pow int) *inf.Dec`

PowerOfTenDec returns an *inf.Dec with the value 10^pow. It should be treated as immutable.

Non-negative powers of 10 will have their value represented in their underlying big.Int with a scale of 0, while negative powers of 10 will have their value represented in their scale with a big.Int value of 1.

#### func PowerOfTenInt ¶

`func PowerOfTenInt(pow int) *big.Int`

PowerOfTenInt returns a *big.Int with the value 10^pow. It should be treated as immutable.

#### func SetFromFloat ¶

`func SetFromFloat(z *inf.Dec, f float64) *inf.Dec`

SetFromFloat sets z to the given float64 value and returns z. The function will panic if the float is NaN or ±Inf.

#### func Sqrt ¶

`func Sqrt(z, x *inf.Dec, s inf.Scale) *inf.Dec`

Sqrt calculates the square root of x to the specified scale and stores the result in z, which is also the return value. The function will panic if x is a negative number.

The square root calculation is implemented using Newton's Method. We start with an initial estimate for sqrt(d), and then iterate:

```x_{n+1} = 1/2 * ( x_n + (d / x_n) ).
```

### Types ¶

This section is empty.