/*
* Copyright (c) 2005, Graph Builder
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* * Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* * Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* * Neither the name of Graph Builder nor the names of its contributors may be
* used to endorse or promote products derived from this software without
* specific prior written permission.
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package com.graphbuilder.math;
import com.graphbuilder.struc.
Bag;
/**
A node of an expression tree that represents a function. A FuncNode can have 0 or more children.
*/
public class
FuncNode extends
TermNode {
private
Bag bag = new
Bag(1);
private double[]
of = new double[1];
public
FuncNode(
String name, boolean
negate) {
super(
name,
negate);
}
/**
Adds the expression as a child.
*/
public void
add(
Expression x) {
insert(
x,
bag.
size());
}
/**
Adds the expression as a child at the specified index.
*/
public void
insert(
Expression x, int
i) {
checkBeforeAccept(
x);
int
oldCap =
bag.
getCapacity();
bag.
insert(
x,
i);
int
newCap =
bag.
getCapacity();
if (
oldCap !=
newCap)
of = new double[
newCap];
x.
parent = this;
}
/**
Removes the specified expression as a child. Does nothing if the expression was not a child.
*/
public void
remove(
Expression x) {
int
size =
bag.
size();
bag.
remove(
x);
if (
size !=
bag.
size())
x.
parent = null;
}
/**
Returns the number of child expressions.
*/
public int
numChildren() {
return
bag.
size();
}
/**
Returns the child expression at the specified index.
*/
public
Expression child(int
i) {
return (
Expression)
bag.
get(
i);
}
/**
Evaluates each of the children, storing the result in an internal double array. The FuncMap is
used to obtain a Function object based on the name of this FuncNode. The function is passed
the double array and returns a result. If negate is true, the result is negated. The result
is then returned. The numParam passed to the function is the number of children of this FuncNode.
*/
public double
eval(
VarMap v,
FuncMap f) {
int
numParam =
bag.
size();
for (int
i = 0;
i <
numParam;
i++)
of[
i] =
child(
i).
eval(
v,
f);
double
result =
f.
getFunction(
name,
numParam).
of(
of,
numParam);
if (
negate)
result = -
result;
return
result;
}
}