/*
* GeoTools - The Open Source Java GIS Toolkit
* http://geotools.org
*
* (C) 2002-2008, Open Source Geospatial Foundation (OSGeo)
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation;
* version 2.1 of the License.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*/
package org.geotools.filter.function;
/**
* Classifies into ranges of minimum and maximum values.
* <p>
* The buckets are defined such that:<br>
* min <= x < max
* </p>
* <p>
* So if you provide the following min/max values:<br>
* min = {3, 6, 9}<br>
* max = {4, 10, 30}<br>
* </p>
* <p>
* The classify function will classify items based on:<br>
* 3 <= x < 4<br>
* 6 <= x < 10<br>
* 9 <= x <= 30<br>
*
* @author Cory Horner, Refractions Research
*
*
*
*
* @source $URL$
*/
public final class RangedClassifier extends Classifier {
Comparable<?> min[];
Comparable<?> max[];
public RangedClassifier(Comparable min[], Comparable max[]) {
this.min = min;
this.max = max;
//initialize titles
this.titles = new String[min.length];
for (int i = 0; i < titles.length; i++) {
titles[i] = generateTitle( min[i], max[i] );
}
}
/**
* Null safe title generation.
*
* @param min
* @param max
* @return generated title
*/
private String generateTitle(Comparable<?> min, Comparable<?> max) {
if( min == null && max == null){
return "Other";
}
else if ( min == null ){
return "Below "+truncateZeros( String.valueOf( max ));
}
else if ( max == null ){
return "Above "+truncateZeros( String.valueOf( min ));
}
else {
return truncateZeros(String.valueOf(min)) + ".." + truncateZeros(String.valueOf(max));
}
}
/**
* Used to remove trailing zeros; preventing out put like 1.00000.
* @param str
* @return origional string with any trailing decimal places removed.
*/
private String truncateZeros(String str) {
if (str.indexOf(".") > -1) {
while(str.endsWith("0")) {
str = str.substring(0, str.length() - 1);
}
if (str.endsWith(".")) {
str = str.substring(0, str.length() - 1);
}
}
return str;
}
public int getSize() {
return Math.min(min.length, max.length);
}
public Object getMin(int slot) {
return min[slot];
}
public Object getMax(int slot) {
return max[slot];
}
public int classify(Object value) {
return classify((Comparable) value);
}
@SuppressWarnings("rawtypes")
private int classify(Comparable<?> val) {
Comparable<?> value = val;
if (val instanceof Integer) { //convert to double as java is stupid
value = new Double(((Integer) val).intValue());
}
//check each slot and see if: min <= value < max
int last = min.length - 1;
for (int i = 0; i <= last; i++) {
Comparable localMin = this.min[i];
Comparable localMax = this.max[i];
if ((localMin == null || localMin.compareTo(value) < 1 ) &&
( localMax == null || localMax.compareTo(value) > 0)) {
return i;
}
}
if (compareTo(max[last],value) == 0) { //if value = max, put it in the last slot
return last;
}
return -1; // value does not fit into any of the provided categories
}
private int compareTo(Comparable compare, Comparable value) {
if( compare == null && value == null ){
return 0;
}
else if( compare == null ){
return -1;
}
else if( value == null ){
return +1;
}
return value.compareTo(compare);
}
}