package net.sf.saxon.option.exslt;
import net.sf.saxon.expr.XPathContext;
import net.sf.saxon.om.Item;
import net.sf.saxon.om.SequenceIterator;
import net.sf.saxon.trans.XPathException;
import net.sf.saxon.value.*;
import java.math.BigDecimal;
import java.util.ArrayList;
/**
* This class implements extension functions in the
* http://exslt.org/math namespace. <p>
*/
public abstract class Math {
/**
* Get the maximum numeric value of the string-value of each of a set of nodes
*/
public static double max (SequenceIterator nsv) throws XPathException {
double max = Double.NEGATIVE_INFINITY;
try {
while (true) {
Item it = nsv.next();
if (it == null) break;
double x = Value.stringToNumber(it.getStringValueCS());
if (Double.isNaN(x)) return x;
if (x>max) max = x;
}
return max;
} catch (NumberFormatException err) {
return Double.NaN;
}
}
/**
* Get the minimum numeric value of the string-value of each of a set of nodes
*/
public static double min (SequenceIterator nsv) throws XPathException {
try {
double min = Double.POSITIVE_INFINITY;
while (true) {
Item it = nsv.next();
if (it == null) break;
double x = Value.stringToNumber(it.getStringValueCS());
if (Double.isNaN(x)) return x;
if (x<min) min = x;
}
return min;
} catch (NumberFormatException e) {
return Double.NaN;
}
}
/**
* Get the items with maximum numeric value of the string-value of each of a sequence of items.
* The items are returned in the order of the original sequence.
*/
public static Value highest (SequenceIterator nsv) throws XPathException {
try {
double max = Double.NEGATIVE_INFINITY;
ArrayList highest = new ArrayList();
while (true) {
Item it = nsv.next();
if (it == null) break;
double x = Value.stringToNumber(it.getStringValueCS());
if (Double.isNaN(x)) return EmptySequence.getInstance();
if (x==max) {
highest.add(it);
} else if (x>max) {
max = x;
highest.clear();
highest.add(it);
}
}
return new SequenceExtent(highest);
} catch (NumberFormatException e) {
return EmptySequence.getInstance();
}
}
/**
* Get the items with minimum numeric value of the string-value of each of a sequence of items
* The items are returned in the order of the original sequence.
*/
public static Value lowest (SequenceIterator nsv) throws XPathException {
try {
double min = Double.POSITIVE_INFINITY;
ArrayList lowest = new ArrayList();
while (true) {
Item it = nsv.next();
if (it == null) break;
double x = Value.stringToNumber(it.getStringValueCS());
if (Double.isNaN(x)) return EmptySequence.getInstance();
if (x==min) {
lowest.add(it);
} else if (x<min) {
min = x;
lowest.clear();
lowest.add(it);
}
}
return new SequenceExtent(lowest);
} catch (NumberFormatException e) {
return EmptySequence.getInstance();
}
}
/**
* Get the absolute value of a numeric value (SStL)
*/
public static double abs (double x) {
return java.lang.Math.abs(x);
}
/**
* Get the square root of a numeric value (SStL)
*/
public static double sqrt (double x) {
return java.lang.Math.sqrt(x);
}
/**
* Get the power of two double or float values, returning the result as a double
*/
// public static double power (double x, double y) { // (SStL)
// return java.lang.Math.pow(x,y);
// }
/**
* Get a number n raised to the power of another number e.
*
* <p>If e is a non-negative integer, then the result will have the same type as n, except
* that a float is always promoted to double.</p>
*
* <p>If e is a negative integer, then the result will have the same type as n except that a float
* is treated as a double and an integer is treated as a decimal.</p>
*
* <p>If e is not an integer (or an xs:decimal representing an integer),
* the result will be a double.</p>
*
* @param n the first argument.
* @param e the second argument. M
* @return the result of n^e
* @throws XPathException if an arithmetic overflow is detected. However, there is no guarantee that
* overflow will always be detected, it may (especially with double arithmetic) lead to wrong answers
* being returned.
*/
public static NumericValue power(NumericValue n, NumericValue e) throws XPathException {
if (n instanceof DoubleValue || n instanceof FloatValue ||
e instanceof DoubleValue || e instanceof FloatValue ||
!e.isWholeNumber()) {
return new DoubleValue(java.lang.Math.pow(n.getDoubleValue(), e.getDoubleValue()));
} else if (e instanceof IntegerValue && n instanceof IntegerValue && e.signum() >= 0) {
long le = e.longValue();
if (le > Integer.MAX_VALUE) {
throw new XPathException("exponent out of range");
}
return IntegerValue.makeIntegerValue(((IntegerValue)n).asBigInteger().pow((int)le));
} else {
BigDecimal nd = n.getDecimalValue();
long le = e.longValue();
if (le > Integer.MAX_VALUE || le < Integer.MIN_VALUE) {
throw new XPathException("exponent out of range");
}
return new DecimalValue(nd.pow((int)le));
// Note JDK 1.5 dependency
// try {
// Class bigDecimalClass = nd.getClass();
// Method pow = bigDecimalClass.getMethod("pow", new Class[]{int.class});
// Integer[] argValues = {new Integer((int)le)};
// BigDecimal result = (BigDecimal)pow.invoke(nd, (Object[])argValues);
// return new DecimalValue(result);
// } catch (NoSuchMethodException err) {
// throw new XPathException("power(decimal) not available in JDK 1.4");
// } catch (IllegalAccessException err) {
// throw new XPathException("power(decimal) not available in JDK 1.4");
// } catch (InvocationTargetException err) {
// throw new XPathException("power(decimal) not available in JDK 1.4");
// }
}
}
/**
* Get a named constant to a given precision (SStL)
*/
public static double constant (XPathContext context, String name, double precision) throws XPathException {
//PI, E, SQRRT2, LN2, LN10, LOG2E, SQRT1_2
String con = "";
if (name.equals("PI")) {
con="3.1415926535897932384626433832795028841971693993751";
} else if (name.equals("E")) {
con="2.71828182845904523536028747135266249775724709369996";
} else if (name.equals("SQRRT2")) {
con="1.41421356237309504880168872420969807856967187537694";
} else if (name.equals("LN2")) {
con="0.69314718055994530941723212145817656807550013436025";
} else if (name.equals("LN10")) {
con="2.302585092994046";
} else if (name.equals("LOG2E")) {
con="1.4426950408889633";
} else if (name.equals("SQRT1_2")) {
con="0.7071067811865476";
} else {
XPathException e = new XPathException("Unknown math constant " + name);
e.setXPathContext(context);
throw e;
}
return Double.parseDouble(con.substring(0, ((int)precision) + 2));
}
/**
* Get the logarithm of a numeric value (SStL)
*/
public static double log (double x) {
return java.lang.Math.log(x);
}
/**
* Get a random numeric value (SStL)
*/
public static double random() {
return java.lang.Math.random();
}
/**
* Get the sine of a numeric value (SStL)
*/
public static double sin (double x) {
return java.lang.Math.sin(x);
}
/**
* Get the cosine of a numeric value (SStL)
*/
public static double cos (double x) {
return java.lang.Math.cos(x);
}
/**
* Get the tangent of a numeric value (SStL)
*/
public static double tan (double x) {
return java.lang.Math.tan(x);
}
/**
* Get the arcsine of a numeric value (SStL)
*/
public static double asin (double x) {
return java.lang.Math.asin(x);
}
/**
* Get the arccosine of a numeric value (SStL)
*/
public static double acos (double x) {
return java.lang.Math.acos(x);
}
/**
* Get the arctangent of a numeric value (SStL)
*/
public static double atan (double x) {
return java.lang.Math.atan(x);
}
/**
* Converts rectangular coordinates to polar (SStL)
*/
public static double atan2 (double x, double y) {
return java.lang.Math.atan2(x,y);
}
/**
* Get the exponential of a numeric value (SStL)
*/
public static double exp (double x) {
return java.lang.Math.exp(x);
}
}
//
// The contents of this file are subject to the Mozilla Public License Version 1.0 (the "License");
// you may not use this file except in compliance with the License. You may obtain a copy of the
// License at http://www.mozilla.org/MPL/
//
// Software distributed under the License is distributed on an "AS IS" basis,
// WITHOUT WARRANTY OF ANY KIND, either express or implied.
// See the License for the specific language governing rights and limitations under the License.
//
// The Original Code is: all this file.
//
// The Initial Developer of the Original Code is Michael H. Kay.
//
// Portions marked SStL were provided by Simon St.Laurent [simonstl@simonstl.com]. All Rights Reserved.
//
// Contributor(s): none.
//