com.scudata.expression.fn.algebra.Linefit Maven / Gradle / Ivy

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SPL(Structured Process Language) A programming language specially for structured data computing.

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package com.scudata.expression.fn.algebra;

import com.scudata.common.MessageManager;
import com.scudata.common.RQException;
import com.scudata.dm.Context;
import com.scudata.dm.Sequence;
import com.scudata.expression.Function;
import com.scudata.expression.IParam;
import com.scudata.resources.EngineMessage;

/**
 * ??????????ϣ??????????ʵ?൱?ڽⷽ??AX=Y??????AΪϵ??????YΪ????????
 * ??AΪm*m??????????ʱ????????Ψһ?⣻??AΪm*n????m>n????????ʱ??????С???˷?????????Ͻ?
 * @author bd
 */
public class Linefit extends Function {
	/**
	 * ??????ʽ????Ч?ԣ???Ч???׳??쳣
	 */
	public void checkValidity() {
		if (param == null) {
			MessageManager mm = EngineMessage.get();
			throw new RQException("linefit" + mm.getMessage("function.missingParam"));
		} else if (param.getSubSize() != 2) {
			MessageManager mm = EngineMessage.get();
			throw new RQException("linefit" + mm.getMessage("function.invalidParam"));
		}
	}
	
	public Object calculate(Context ctx) {
		IParam sub1 = param.getSub(0);
		IParam sub2 = param.getSub(1);
		if (sub1 == null || sub2 == null) {
			MessageManager mm = EngineMessage.get();
			throw new RQException("linefit" + mm.getMessage("function.invalidParam"));
		}
		
		Object o1 = sub1.getLeafExpression().calculate(ctx);
		Object o2 = sub2.getLeafExpression().calculate(ctx);
		if (o1 instanceof Sequence && o2 instanceof Sequence) {
			Matrix A = new Matrix((Sequence)o1);
			Matrix B = new Matrix((Sequence)o2);
			boolean oneline = B.getRows() == 1;
			if (oneline) {
				B = B.transpose();
			}
			
			if (A.getCols() == 0 || A.getRows() == 0) {
				MessageManager mm = EngineMessage.get();
				throw new RQException("linefit" + mm.getMessage("function.paramTypeError"));
			}
			else if (B.getCols() == 0 || B.getRows() == 0) {
				MessageManager mm = EngineMessage.get();
				throw new RQException("linefit" + mm.getMessage("function.paramTypeError"));
			}
			Matrix X = A.solve(B);
			if (X == null) {
				return null;
			}
			if (oneline) {
				double[][] vs = X.getArray();
				int rows = vs.length;
				if (rows > 0) {
					int cols = vs[0].length;
					if (cols == 1) {
						Sequence result = new Sequence(rows);
						for (int i = 0; i < rows; i++) {
							result.add(vs[i][0]);
						}
						return result;
					}
					else if (rows == 1) {
						Sequence result = new Sequence(cols);
						for (int i = 0; i < cols; i++) {
							result.add(vs[0][i]);
						}
						return result;
					}
				}
			}
			return X.toSequence(option, false);
		} else {
			MessageManager mm = EngineMessage.get();
			throw new RQException("linefit" + mm.getMessage("function.paramTypeError"));
		}
	}
}