TechnicalVariable.java

package jscl.math;

import jscl.math.function.Constant;

import javax.annotation.Nonnull;
import java.util.Collections;
import java.util.Set;

public class TechnicalVariable extends Variable {
    public int subscript[];

    public TechnicalVariable(String name) {
        this(name, new int[0]);
    }

    public TechnicalVariable(String name, int subscript[]) {
        super(name);
        this.subscript = subscript;
    }

    public Generic antiDerivative(Variable variable) throws NotIntegrableException {
        throw new NotIntegrableException(this);
    }

    @Nonnull
    public Generic derivative(Variable variable) {
        if (isIdentity(variable)) return JsclInteger.valueOf(1);
        else return JsclInteger.valueOf(0);
    }

    public Generic substitute(Variable variable, Generic generic) {
        if (isIdentity(variable)) return generic;
        else return expressionValue();
    }

    public Generic expand() {
        return expressionValue();
    }

    public Generic factorize() {
        return expressionValue();
    }

    public Generic elementary() {
        return expressionValue();
    }

    public Generic simplify() {
        return expressionValue();
    }

    public Generic numeric() {
        throw new ArithmeticException("Could not evaluate numeric value for technical variable!");
    }

    public boolean isConstant(Variable variable) {
        return !isIdentity(variable);
    }

    public int compareTo(Variable variable) {
        if (this == variable) return 0;
        int c = comparator.compare(this, variable);
        if (c < 0) return -1;
        else if (c > 0) return 1;
        else {
            TechnicalVariable v = (TechnicalVariable) variable;
            c = name.compareTo(v.name);
            if (c < 0) return -1;
            else if (c > 0) return 1;
            else return compareSubscript(subscript, v.subscript);
        }
    }

    public int compareSubscript(int c1[], int c2[]) {
        if (c1.length < c2.length) return -1;
        else if (c1.length > c2.length) return 1;
        for (int i = 0; i < c1.length; i++) {
            if (c1[i] < c2[i]) return -1;
            else if (c1[i] > c2[i]) return 1;
        }
        return 0;
    }

    public String toString() {
        StringBuffer buffer = new StringBuffer();
        buffer.append(name);
        if (subscript.length == 1) buffer.append(subscript[0]);
        else for (int i = 0; i < subscript.length; i++) buffer.append("[").append(subscript[i]).append("]");
        return buffer.toString();
    }

    public String toJava() {
        return null;
    }

    public String toMathML(Object data) {
        return null;
    }

    @Nonnull
    public Variable newInstance() {
        return new TechnicalVariable(name);
    }

    @Nonnull
    @Override
    public Set<? extends Constant> getConstants() {
        // todo serso: check
        return Collections.emptySet();
    }
}