jscl.math.operator.Sum Maven / Gradle / Ivy
package jscl.math.operator;
import jscl.math.Generic;
import jscl.math.JsclInteger;
import jscl.math.NotIntegerException;
import jscl.math.Variable;
import jscl.mathml.MathML;
import javax.annotation.Nonnull;
public class Sum extends Operator {
public static final String NAME = "Σ";
public Sum(Generic expression, Generic variable, Generic from, Generic to) {
super(NAME, new Generic[]{expression, variable, from, to});
}
private Sum(Generic parameters[]) {
super(NAME, parameters);
}
@Override
public int getMinParameters() {
return 4;
}
@Nonnull
@Override
protected String formatUndefinedParameter(int i) {
switch (i) {
case 0:
return "f(i)";
case 1:
return "i";
case 2:
return "from";
case 3:
return "to";
default:
return super.formatUndefinedParameter(i);
}
}
public Generic selfExpand() {
Variable variable = parameters[1].variableValue();
try {
int from = parameters[2].integerValue().intValue();
int to = parameters[3].integerValue().intValue();
Generic result = JsclInteger.ZERO;
for (int i = from; i <= to; i++) {
result = result.add(parameters[0].substitute(variable, JsclInteger.valueOf(i)));
}
return result;
} catch (NotIntegerException e) {
// ok
}
return expressionValue();
}
public void toMathML(MathML element, Object data) {
int exponent = data instanceof Integer ? (Integer) data : 1;
if (exponent == 1) bodyToMathML(element);
else {
MathML e1 = element.element("msup");
MathML e2 = element.element("mfenced");
bodyToMathML(e2);
e1.appendChild(e2);
e2 = element.element("mn");
e2.appendChild(element.text(String.valueOf(exponent)));
e1.appendChild(e2);
element.appendChild(e1);
}
}
@Nonnull
@Override
public Operator newInstance(@Nonnull Generic[] parameters) {
return new Sum(parameters);
}
void bodyToMathML(MathML element) {
MathML e1 = element.element("mrow");
MathML e2 = element.element("munderover");
MathML e3 = element.element("mo");
e3.appendChild(element.text("\u2211"));
e2.appendChild(e3);
e3 = element.element("mrow");
parameters[1].toMathML(e3, null);
MathML e4 = element.element("mo");
e4.appendChild(element.text("="));
e3.appendChild(e4);
parameters[2].toMathML(e3, null);
e2.appendChild(e3);
parameters[3].toMathML(e2, null);
e1.appendChild(e2);
parameters[0].toMathML(e1, null);
element.appendChild(e1);
}
@Nonnull
public Variable newInstance() {
return new Sum(null, null, null, null);
}
}