package net.iponweb.disthene.reader.graphite.functions;
import net.iponweb.disthene.reader.beans.TimeSeries;
import net.iponweb.disthene.reader.exceptions.EvaluationException;
import net.iponweb.disthene.reader.exceptions.InvalidArgumentException;
import net.iponweb.disthene.reader.exceptions.TimeSeriesNotAlignedException;
import net.iponweb.disthene.reader.graphite.Target;
import net.iponweb.disthene.reader.graphite.evaluation.TargetEvaluator;
import net.iponweb.disthene.reader.utils.TimeSeriesUtils;
import java.util.ArrayList;
import java.util.List;
/**
* @author Andrei Ivanov
*/
public class LogarithmFunction extends DistheneFunction {
public LogarithmFunction(String text) {
super(text, "logarithm");
}
@Override
public List<TimeSeries> evaluate(TargetEvaluator evaluator) throws EvaluationException {
List<TimeSeries> processedArguments = new ArrayList<>();
processedArguments.addAll(evaluator.eval((Target) arguments.get(0)));
if (processedArguments.size() == 0) return new ArrayList<>();
if (!TimeSeriesUtils.checkAlignment(processedArguments)) {
throw new TimeSeriesNotAlignedException();
}
double base = arguments.size() > 1 ? (Double) arguments.get(1) : 10.;
double logBase = Math.log(base);
int length = processedArguments.get(0).getValues().length;
for (TimeSeries ts : processedArguments) {
for (int i = 0; i < length; i++) {
if (ts.getValues()[i] != null && ts.getValues()[i] > 0 && logBase != 0) {
ts.getValues()[i] = Math.log(ts.getValues()[i]) / logBase;
} else {
ts.getValues()[i] = null;
}
}
ts.setName("logarithm(" + ts.getName() + "," + base + ")");
}
return processedArguments;
}
@Override
public void checkArguments() throws InvalidArgumentException {
if (arguments.size() > 2 || arguments.size() == 0) throw new InvalidArgumentException("logarithm: number of arguments is " + arguments.size() + ". Must be one or two.");
if (!(arguments.get(0) instanceof Target)) throw new InvalidArgumentException("logarithm: argument is " + arguments.get(0).getClass().getName() + ". Must be series");
if (arguments.size() > 1 && !(arguments.get(1) instanceof Double)) throw new InvalidArgumentException("logarithm: argument is " + arguments.get(1).getClass().getName() + ". Must be a number");
if (arguments.size() > 1 && ((Double) arguments.get(1) <= 0)) throw new InvalidArgumentException("logarithm: base is " + arguments.get(1).getClass().getName() + ". Must be > 0.");
}
}