Are there libraries for Square Root over BigDecimal? [closed]

Answer 1

JScience v4.3.1 has a Real class which seems to be the equivalent of BigDecimal and that might help you. An example of usage:

// The Square Root of Two, to 30 digits
// According to "The Square Root of Two, to 5 million digits."
// Source: http://www.gutenberg.org/files/129/129.txt
System.out.println("1.41421356237309504880168872420");

// Using JScience with 50 digits precision
Real.setExactPrecision(50);
System.out.println(Real.valueOf(2).sqrt());

// Using default java implementation
System.out.println(Math.sqrt(2));

> 1.41421356237309504880168872420
> 1.414213562373095048801689
> 1.4142135623730951

Edit: Updated the code and the links to reflect the current version at the time (v4.3.1). Based on @ile an @Tomasz comments, thanks.

Answer 2

Try Big Square Roots. It uses the Newton's method for approximating solutions such as square roots.

Answer 3

(This is may not be a solution for you)

As long as your BigDecimal is in the range of double, you can convert the BigDecimal to double, use Math.sqrt() and promote the double back to BigDecimal. It will probably be faster than carrying out the calculation on BigDecimals. In many cases the loss of precision due to conversion between types will be negligible compared to the inevitable error in computing the square root.