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Copy pathAbs.java
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77 lines (66 loc) · 2.09 KB
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package symjava.symbolic;
import java.util.Map;
import com.sun.org.apache.bcel.internal.Constants;
import com.sun.org.apache.bcel.internal.generic.ConstantPoolGen;
import com.sun.org.apache.bcel.internal.generic.InstructionFactory;
import com.sun.org.apache.bcel.internal.generic.InstructionHandle;
import com.sun.org.apache.bcel.internal.generic.InstructionList;
import com.sun.org.apache.bcel.internal.generic.MethodGen;
import com.sun.org.apache.bcel.internal.generic.ObjectType;
import com.sun.org.apache.bcel.internal.generic.Type;
import symjava.symbolic.Expr.TYPE;
import symjava.symbolic.arity.UnaryOp;
import symjava.symbolic.utils.Utils;
public class Abs extends UnaryOp {
public Abs(Expr arg) {
super(arg);
label = "|" + arg + "|";
sortKey = label;
}
@Override
public Expr simplify() {
return this;
}
@Override
public boolean symEquals(Expr other) {
if(other instanceof Abs) {
Utils.symCompare(this.arg, ((Cos) other).arg);
}
return false;
}
public static Expr simplifiedIns(Expr expr) {
return new Abs(expr);
}
/**
* Recall that |f(x)| = sqrt(f(x)*f(x)), so
* |f(x)|' = f(x)*f'(x)/|f(x)|
*/
@Override
public Expr diff(Expr x) {
return arg.multiply(arg.diff(x)).divide(this);
}
@Override
public InstructionHandle bytecodeGen(String clsName, MethodGen mg,
ConstantPoolGen cp, InstructionFactory factory,
InstructionList il, Map<String, Integer> argsMap, int argsStartPos,
Map<Expr, Integer> funcRefsMap) {
InstructionHandle startPos = arg.bytecodeGen(clsName, mg, cp, factory, il, argsMap, argsStartPos, funcRefsMap);
if(arg.getType() == TYPE.MATRIX || arg.getType() == TYPE.VECTOR) {
il.append(factory.createInvoke("symjava.symbolic.utils.BytecodeOpSupport", "abs",
new ObjectType("Jama.Matrix"),
new Type[] { new ObjectType("Jama.Matrix") },
Constants.INVOKESTATIC));
} else {
il.append(factory.createInvoke("java.lang.Math", "abs",
Type.DOUBLE,
new Type[] { Type.DOUBLE },
Constants.INVOKESTATIC));
}
return startPos;
}
@Override
public void updateLabel() {
label = "|" + arg + "|";
sortKey = label;
}
}