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```{index} single: Math::BigInt::Calc
```

# Math::BigInt::Calc

pure Perl module to support Math::BigInt

## SYNOPSIS

```perl
## to use it with Math::BigInt
use Math::BigInt lib => 'Calc';

## to use it with Math::BigFloat
use Math::BigFloat lib => 'Calc';

## to use it with Math::BigRat
use Math::BigRat lib => 'Calc';

## explicitly set base length and whether to "use integer"
use Math::BigInt::Calc base_len => 4, use_int => 1;
use Math::BigInt lib => 'Calc';
```

## DESCRIPTION

Math::BigInt::Calc inherits from Math::BigInt::Lib.

In this library, the numbers are represented interenally in base B = 10\*\*N,
where N is the largest possible integer that does not cause overflow in the
intermediate computations. The base B elements are stored in an array, with the
least significant element stored in array element zero. There are no leading
zero elements, except a single zero element when the number is zero. For
instance, if B = 10000, the number 1234567890 is represented internally as
\[7890, 3456, 12\].

## OPTIONS

When the module is loaded, it computes the maximum exponent, i.e., power of 10,
that can be used with and without "use integer" in the computations. The default
is to use this maximum exponent. If the combination of the 'base\_len' value and
the 'use\_int' value exceeds the maximum value, an error is thrown.

- base\_len

    The base length can be specified explicitly with the 'base\_len' option. The
    value must be a positive integer.

    ```perl
    use Math::BigInt::Calc base_len => 4;  # use 10000 as internal base
    ```

- use\_int

    This option is used to specify whether "use integer" should be used in the
    internal computations. The value is interpreted as a boolean value, so use 0 or
    "" for false and anything else for true. If the 'base\_len' is not specified
    together with 'use\_int', the current value for the base length is used.

    ```perl
    use Math::BigInt::Calc use_int => 1;   # use "use integer" internally
    ```

## METHODS

This overview constains only the methods that are specific to
`Math::BigInt::Calc`. For the other methods, see [Math::BigInt::Lib](Lib.md).

- \_base\_len()

    Specify the desired base length and whether to enable "use integer" in the
    computations.

    ```perl
    Math::BigInt::Calc -> _base_len($base_len, $use_int);
    ```

    Note that it is better to specify the base length and whether to use integers as
    options when the module is loaded, for example like this

    ```perl
    use Math::BigInt::Calc base_len => 6, use_int => 1;
    ```

## SEE ALSO

[Math::BigInt::Lib](Lib.md) for a description of the API.

Alternative libraries [Math::BigInt::FastCalc](FastCalc.md), [Math::BigInt::GMP](https://metacpan.org/pod/Math::BigInt::GMP),
[Math::BigInt::Pari](https://metacpan.org/pod/Math::BigInt::Pari), [Math::BigInt::GMPz](https://metacpan.org/pod/Math::BigInt::GMPz), and [Math::BigInt::BitVect](https://metacpan.org/pod/Math::BigInt::BitVect).

Some of the modules that use these libraries [Math::BigInt](../BigInt.md),
[Math::BigFloat](../BigFloat.md), and [Math::BigRat](../BigRat.md).