Precise floating-point operations include addition, subtraction, multiplication, division, and rounding.

Import java. Math. bigdecimal;

 

/**

* Because Java's simple types cannot accurately perform floating-point operations, this tool provides

* A real floating point number operation, including addition, subtraction, multiplication, division, and rounding.

*/

Public class Arith {

 

// Default division operation precision

Private Static final int def_div_scale = 10;

 

// This class cannot be instantiated

Private Arith (){

}

 

 

/**

* Provides precise addition operations.

* @ Param V1 add count

* @ Param V2 addend

* @ Return the sum of the two parameters

*/

Public static double add (double V1, double V2 ){

Bigdecimal b1 = new bigdecimal (double. tostring (V1 ));

Bigdecimal b2 = new bigdecimal (double. tostring (V2 ));

Return b1.add (B2). doublevalue ();

}

 

/**

* Provides precise subtraction operations.

* @ Param V1 subtrahend

* @ Param V2 subtrahend

* @ Return Difference Between Two Parameters

*/

Public static double sub (double V1, double V2 ){

Bigdecimal b1 = new bigdecimal (double. tostring (V1 ));

Bigdecimal b2 = new bigdecimal (double. tostring (V2 ));

Return b1.subtract (B2). doublevalue ();

}

 

/**

* Provides precise multiplication.

* @ Param V1 Multiplier

* @ Param V2 Multiplier

* @ Return the product of two parameters

*/

Public static double MUL (double V1, double V2 ){

Bigdecimal b1 = new bigdecimal (double. tostring (V1 ));

Bigdecimal b2 = new bigdecimal (double. tostring (V2 ));

Return b1.multiply (B2). doublevalue ();

}

 

/**

* Provides (relatively) accurate Division operations, accurate

* 10 digits after the decimal point, and the digits after the decimal point are rounded down.

* @ Param V1 Divisor

* @ Param V2 Divisor

* @ Return parameter vendors

*/

Public static double Div (double V1, double V2 ){

Return Div (V1, V2, def_div_scale );

}

 

/**

* Provides (relatively) accurate Division operations. In case of division, the scale parameter indicates

* Set the precision. The number is rounded down.

* @ Param V1 Divisor

* @ Param V2 Divisor

* @ Param scale indicates the number of digits after the decimal point.

* @ Return parameter vendors

*/

Public static double Div (double V1, double V2, int scale ){

If (scale <0 ){

Throw new illegalargumentexception (

"The scale must be a positive integer or zero ");

}

Bigdecimal b1 = new bigdecimal (double. tostring (V1 ));

Bigdecimal b2 = new bigdecimal (double. tostring (V2 ));

Return b1.divide (B2, scale, bigdecimal. round_half_up). doublevalue ();

}

 

/**

* Provides precise rounding of decimal places.

* @ Param V refers to the number rounded up.

* @ Param scale: number of digits after the decimal point

* @ Return returns the result after rounding.

*/

Public static double round (Double V, int scale ){

If (scale <0 ){

Throw new illegalargumentexception (

"The scale must be a positive integer or zero ");

}

Bigdecimal B = new bigdecimal (double. tostring (V ));

Bigdecimal one = new bigdecimal ("1 ");

Return B. Divide (one, scale, bigdecimal. round_half_up). doublevalue ();

}

};