/**
* Creates a new data row reader for sparse format. The attributes indices must not be set. If
* they are, they are reassigned new values when this constructor is called!
*
* @param factory Factory used to create {@link DataRow} instances.
* @param format One Out of FORMAT_XY, FORMAT_YX, FORMAT_PREFIX, and FORMAT_SEPARATE_FILE.
* @param prefixMap Maps prefixes to special attribute names (e.g. "l" to
* "label").
* @param attributeSet Set of regular and special attributes.
* @param attributeReader Reader for the data
* @param labelReader Reader for the labels. Only necessary if format is FORMAT_SEPARATE_FILE.
* @param sampleSize sample size, may be -1 for no limit.
* @param useQuotesForNominalValues Determines whether nominal values are surrounded by quotes or
* not. If <code>useQuotesForNominalValues == true</code> the first and last character of the
* nominal values are ignored.
* @param quoteChar The char that is used to surround nominal values.
*/
public SparseFormatDataRowReader(
DataRowFactory factory,
int format,
Map<String, String> prefixMap,
AttributeSet attributeSet,
Reader attributeReader,
Reader labelReader,
int sampleSize,
boolean useQuotesForNominalValues,
char quoteChar) {
super(factory);
this.format = format;
this.prefixMap = prefixMap;
this.attributeSet = attributeSet;
if (attributeSet == null) {
throw new IllegalArgumentException("AttributeSet must not be null.");
}
this.dimension = attributeSet.getAllAttributes().size();
this.maxNumber = sampleSize;
this.inAttributes = new BufferedReader(attributeReader);
if (format == FORMAT_SEPARATE_FILE) {
if (labelReader == null)
throw new IllegalArgumentException(
"labelReader must not be null if format is 'separate_file'!");
this.inLabels = new BufferedReader(labelReader);
}
if (format != FORMAT_NO_LABEL) {
if (attributeSet.getSpecialAttribute("label") == null) {
throw new IllegalArgumentException(
"If format is not no_label, label attribute must be defined.");
}
}
this.useQuotesForNominalValues = useQuotesForNominalValues;
this.quoteChar = quoteChar;
}
private boolean readLine() throws IOException {
String attributeLine = null;
do {
attributeLine = inAttributes.readLine();
if (attributeLine == null) return false;
} while (attributeLine.startsWith("#") || (attributeLine.length() == 0));
this.currentDataRow = getFactory().create(dimension);
StringTokenizer tokenizer = new StringTokenizer(attributeLine);
String labelString = null;
if (format == FORMAT_YX) {
labelString = tokenizer.nextToken();
} else if (format == FORMAT_SEPARATE_FILE) {
do {
labelString = inLabels.readLine();
if (labelString == null) return false;
} while (labelString.startsWith("#") || (labelString.length() == 0));
}
while (tokenizer.hasMoreTokens()) {
String attributeToken = tokenizer.nextToken();
int colonIndex = attributeToken.indexOf(':');
if ((format == FORMAT_XY) && (colonIndex == -1)) {
if (labelString != null) {
throw new IOException("Malformed line in examplefile: " + attributeToken);
} else {
labelString = attributeToken;
}
} else {
String pos = attributeToken.substring(0, colonIndex); // references
// the
// attribute
String value = attributeToken.substring(colonIndex + 1); // the
// attribute
// value
Attribute attribute = null; // the referenced attribute
try {
int index = Integer.parseInt(pos) - 1;
if ((index < 0) || (index >= attributeSet.getNumberOfRegularAttributes()))
throw new IOException(
"Attribute index out of range: '"
+ (index + 1)
+ "'! Index must be between 1 and dimension "
+ attributeSet.getNumberOfRegularAttributes()
+ "!");
attribute = attributeSet.getAttribute(index);
} catch (NumberFormatException e) {
String specialAttributeName = prefixMap.get(pos);
if (specialAttributeName == null) {
attribute = attributeSet.getSpecialAttribute(pos);
if (attribute == null)
throw new IOException(
"Illegal attribute index: '"
+ pos
+ "' (legal values are integers and defined prefixes for special attributes (Parameter prefix_map of SparseFormatExampleSource))!");
} else {
attribute = attributeSet.getSpecialAttribute(specialAttributeName);
}
if (attribute == null)
throw new IOException("Unknown special attribute: " + specialAttributeName);
}
if (attribute != null) {
if (attribute.isNominal()) {
if (useQuotesForNominalValues) {
String quote = Character.toString(quoteChar);
if (value.startsWith(quote) && value.endsWith(quote)) {
value = value.substring(1, value.length() - 1);
} else {
throw new RuntimeException(
"The value ' "
+ value
+ " ' does not start and end with a quote character ' "
+ quote
+ " '.");
}
Tools.unescape(value);
}
currentDataRow.set(attribute, attribute.getMapping().mapString(value));
} else {
try {
currentDataRow.set(attribute, Double.parseDouble(value));
} catch (NumberFormatException e) {
throw new IOException("Attribute is not numerical: '" + value + "'!");
}
}
}
}
}
if (labelString != null) {
Attribute label = attributeSet.getSpecialAttribute("label");
if (label.isNominal()) {
currentDataRow.set(label, label.getMapping().mapString(labelString));
} else {
try {
currentDataRow.set(label, Double.parseDouble(labelString));
} catch (NumberFormatException e) {
throw new IOException("Label is not numerical: '" + labelString + "'.");
}
}
}
currentDataRow.trim();
return true;
}