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eduardovalentim edited this page Aug 30, 2022 · 4 revisions

Examples

Algebra

  1. Define the @Formula you need in an interface method:
import java.math.BigDecimal;
import com.github.eduardovalentim.easymath.annotations.Formula;

public interface Algebra {

	@Formula("(a ^ 3) + (b ^ 3)")
	public double cubesSum(Number... args);

	@Formula("(a + b) * ((a ^ 2) - (a * b) + (b ^ 2))")
	public BigDecimal cubesSumExpansion(Number... args);
}
  1. Compile the code (of course you'll need setup) and see an automagically implementation of the interface Algebra.
import static com.github.eduardovalentim.easymath.Numbers.*;

import java.math.BigDecimal;
import java.math.MathContext;
import java.math.RoundingMode;

import javax.annotation.Generated;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.github.eduardovalentim.easymath.FunctionCatalog;
import com.github.eduardovalentim.easymath.functions.CoreFunctionCatalog;

@Generated("com.github.eduardovalentim.easymath.processor.mathematical.MathematicalProcessor")
@SuppressWarnings({"all", "warnings", "unchecked", "unused", "cast"})
public class AlgebraImpl implements Algebra {

	private static MessageFactory factory = new MessageFormatMessageFactory();
	private static Logger logger = LogManager.getLogger(AlgebraImpl.class, factory);

	private static final java.math.BigDecimal BD2 = new BigDecimal("2");
	private static final double D3 = 3D;

	private FunctionCatalog catalog = new CoreFunctionCatalog();

	/**
	 * Public constructor with catalog customization
	 * @param catalogs
	 */
        public AlgebraImpl(FunctionCatalog... catalogs) {
		/*
		 * Method protection
		 */
		if (catalogs == null)
			throw new IllegalArgumentException("Argument 'catalogs' cannot be null.");
		/*
		 * Join the default catalog with all informed
		 */
		this.catalog = catalog.join(catalogs);
	}

	/**
	 * The implementation of the formula: (a ^ 3) + (b ^ 3)
	 * 
	 * @param inputs The inputs for calculation
	 * @return the result of the calculation
	 */
	@Override
	public double cubesSum(Number... inputs) {
		/*
		 * Method protection block
		 */
		if (inputs == null)
			throw new IllegalArgumentException("Argument 'inputs' cannot be null.");
		if (inputs.length != 2)
			throw new IllegalArgumentException(
					"Length mismatch for argument 'inputs'. Expected '2' actual '" + inputs.length + "'");
		/*
		 * Typecast block
		 */
		double a = toDouble(inputs[0], 0);
		double b = toDouble(inputs[1], 1);

		return cubesSum(a, b);
	}

	/**
	 * The implementation of the formula: (a ^ 3) + (b ^ 3)
	 * 
	 * @param a The a input
	 * @param b The b input
	 * @return the result of the calculation
	 */
	protected double cubesSum(double a, double b) {
		logger.debug(
				"Resolving expression (a ^ 3) + (b ^ 3) with ({0, number, #.##########} ^ 3) + ({1, number, #.##########} ^ 3)",
				a, b);
		/*
		 * Function precision and rounding mode definition
		 */
		MathContext mc = new MathContext(7, RoundingMode.HALF_UP);
		/*
		 * Function resolution
		 */
		double r1 = toDouble(catalog.solve("pow", mc, a, D3), 0);
		logger.trace(
				"Resolving operation a^3 with {0, number, #.##########}^{1, number, #.##########} = {2, number, #.##########}",
				a, D3, r1);
		double r2 = toDouble(catalog.solve("pow", mc, b, D3), 0);
		logger.trace(
				"Resolving operation b^3 with {0, number, #.##########}^{1, number, #.##########} = {2, number, #.##########}",
				b, D3, r2);
		double r0 = r1 + r2;
		logger.trace(
				"Resolving operation (a^3)+(b^3) with {0, number, #.##########}+{1, number, #.##########} = {2, number, #.##########}",
				r1, r2, r0);
		// ensure the necessary precision
		logger.trace("Rounding the result {0, number, #.##########}", r0);
		r0 = round(r0, mc);
		/*
		 * Result
		 */
		logger.debug("Returning {0, number, #.#######} as the result!", r0);
		return r0;
	}

	/**
	 * The implementation of the formula: (a + b) * ((a ^ 2) - (a * b) + (b ^ 2))
	 * 
	 * @param inputs The inputs for calculation
	 * @return the result of the calculation
	 */
	@Override
	public java.math.BigDecimal cubesSumExpansion(Number... inputs) {
		/*
		 * Method protection block
		 */
		if (inputs == null)
			throw new IllegalArgumentException("Argument 'inputs' cannot be null.");
		if (inputs.length != 2)
			throw new IllegalArgumentException(
					"Length mismatch for argument 'inputs'. Expected '2' actual '" + inputs.length + "'");
		/*
		 * Typecast block
		 */
		java.math.BigDecimal a = toBigDecimal(inputs[0], 0);
		java.math.BigDecimal b = toBigDecimal(inputs[1], 1);

		return cubesSumExpansion(a, b);
	}

	/**
	 * The implementation of the formula: (a + b) * ((a ^ 2) - (a * b) + (b ^ 2))
	 * 
	 * @param a The a input
	 * @param b The b input
	 * @return the result of the calculation
	 */
	protected java.math.BigDecimal cubesSumExpansion(java.math.BigDecimal a, java.math.BigDecimal b) {
		logger.debug(
				"Resolving expression (a + b) * ((a ^ 2) - (a * b) + (b ^ 2)) with ({0, number, #.##########} + {1, number, #.##########}) * (({0, number, #.##########} ^ 2) - ({0, number, #.##########} * {1, number, #.##########}) + ({1, number, #.##########} ^ 2))",
				a, b);
		/*
		 * Method protection block
		 */
		if (a == null)
			throw new IllegalArgumentException("Argument 'a' cannot be null.");
		if (b == null)
			throw new IllegalArgumentException("Argument 'b' cannot be null.");
		/*
		 * Function precision and rounding mode definition
		 */
		MathContext mc = new MathContext(7, RoundingMode.HALF_UP);
		/*
		 * Function resolution
		 */
		java.math.BigDecimal r1 = a.add(b, mc);
		logger.trace(
				"Resolving operation a+b with {0, number, #.##########}+{1, number, #.##########} = {2, number, #.##########}",
				a, b, r1);
		java.math.BigDecimal r4 = toBigDecimal(catalog.solve("pow", mc, a, BD2), 0);
		logger.trace(
				"Resolving operation a^2 with {0, number, #.##########}^{1, number, #.##########} = {2, number, #.##########}",
				a, BD2, r4);
		java.math.BigDecimal r5 = a.multiply(b, mc);
		logger.trace(
				"Resolving operation a*b with {0, number, #.##########}*{1, number, #.##########} = {2, number, #.##########}",
				a, b, r5);
		java.math.BigDecimal r3 = r4.subtract(r5, mc);
		logger.trace(
				"Resolving operation (a^2)-(a*b) with {0, number, #.##########}-{1, number, #.##########} = {2, number, #.##########}",
				r4, r5, r3);
		java.math.BigDecimal r6 = toBigDecimal(catalog.solve("pow", mc, b, BD2), 0);
		logger.trace(
				"Resolving operation b^2 with {0, number, #.##########}^{1, number, #.##########} = {2, number, #.##########}",
				b, BD2, r6);
		java.math.BigDecimal r2 = r3.add(r6, mc);
		logger.trace(
				"Resolving operation (a^2)-(a*b)+(b^2) with {0, number, #.##########}+{1, number, #.##########} = {2, number, #.##########}",
				r3, r6, r2);
		java.math.BigDecimal r0 = r1.multiply(r2, mc);
		logger.trace(
				"Resolving operation (a+b)*((a^2)-(a*b)+(b^2)) with {0, number, #.##########}*{1, number, #.##########} = {2, number, #.##########}",
				r1, r2, r0);
		/*
		 * Result
		 */
		logger.debug("Returning {0, number, #.#######} as the result!", r0);
		return r0;
	}
}
  1. If you configure your log subsystem to DEBUG level, you will see extra lines in the output.
[DEBUG] c.g.e.e.t.AlgebraImpl.cubesSum Resolving expression (a ^ 3) + (b ^ 3) with ( 7,3 ^ 3) + ( 3,7 ^ 3)
[DEBUG] c.g.e.e.t.AlgebraImpl.cubesSum Returning  439,67 as the result!

If you need a deeper understanding of how the formula is calculated, set the log level to TRACE.

[DEBUG] c.g.e.e.t.AlgebraImpl.cubesSum Resolving expression (a ^ 3) + (b ^ 3) with ( 7,3 ^ 3) + ( 3,7 ^ 3)
[TRACE] c.g.e.e.t.AlgebraImpl.cubesSum Resolving operation a^3 with  7,3^ 3 =  389,017
[TRACE] c.g.e.e.t.AlgebraImpl.cubesSum Resolving operation b^3 with  3,7^ 3 =  50,653
[TRACE] c.g.e.e.t.AlgebraImpl.cubesSum Resolving operation (a^3)+(b^3) with  389,017+ 50,653 =  439,67
[TRACE] c.g.e.e.t.AlgebraImpl.cubesSum Rounding the result  439,67
[DEBUG] c.g.e.e.t.AlgebraImpl.cubesSum Returning  439,67 as the result!
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