Hi,
   I have just started using phoenix. I have implemented udf and deployed
in phoenix. Following is code snippet for udf:


import org.apache.phoenix.expression.function.ScalarFunction;
import org.apache.phoenix.parse.FunctionParseNode.Argument;
import org.apache.phoenix.parse.FunctionParseNode.BuiltInFunction;
import org.apache.phoenix.schema.tuple.Tuple;
import org.apache.phoenix.schema.types.PDataType;
import org.apache.phoenix.schema.types.PDouble;
import org.apache.phoenix.schema.types.PVarchar;

@BuiltInFunction(name = CalDistanceFunction.NAME, args = {
    @Argument(allowedTypes = { PVarchar.class }),
    @Argument(allowedTypes = { PVarchar.class }),
    @Argument(allowedTypes = { PVarchar.class }) })
public class CalDistanceFunction extends ScalarFunction {
  Logger LOG = Logger.getLogger(CalDistanceFunction.class);
  public static final String NAME = "CALDIST";
  private String startLat;
  private String startLong;

  public CalDistanceFunction(List<Expression> children) {
    super(children);
    init();
  }

  private void init() {
    LOG.debug("init function");
    LOG.debug("init array size " + getChildren().size());
    Expression startLatExp = getChildren().get(0);
    Expression startLongExp = getChildren().get(1);
    if (startLatExp instanceof LiteralExpression
        && startLongExp instanceof LiteralExpression) {
      startLat = ((LiteralExpression) startLatExp).getValue().toString();
      startLong = ((LiteralExpression) startLongExp).getValue().toString();
    }
  }

  @Override
  public boolean evaluate(Tuple tuple, ImmutableBytesWritable ptr) {
    if (!getChildren().get(2).evaluate(tuple, ptr)) {
      return false;
    }
    String latLangStr = (String) PVarchar.INSTANCE.toObject(ptr,
        getChildren().get(0).getSortOrder());
    String[] splits = latLangStr.split(",");
    String latStr = splits[0];
    String longStr = splits[1];
    if (latStr == null || longStr == null) {
      LOG.info("returning null");
      return false;
    }
    double latValue, longValue, startLatValue, startLongValue;
    try {
      latValue = Double.parseDouble(latStr);
      longValue = Double.parseDouble(longStr);
      startLatValue = Double.parseDouble(startLat);
      startLongValue = Double.parseDouble(startLong);
    } catch (NumberFormatException e) {
      //LOG.error("evaluation failure", e);
      ptr.set(PDouble.INSTANCE.toBytes(Double.MAX_VALUE));
      return true;
    }
    double answer =
        Math.sqrt(Math.pow(111.699 * (latValue - startLatValue), 2) +
Math.pow(
            111.699 * (startLongValue - longValue) * Math.cos(latValue /
57.3),
            2));
    LOG.debug("dz distance calculated : " + answer);
    ptr.set(PDouble.INSTANCE.toBytes(answer));
    return true;
  }

  @Override
  public PDataType getDataType() {
    return PDouble.INSTANCE;
  }

  @Override
  public String getName() {
    return NAME;
  }

}

It woking fine with normal select query

select latitude, longitude, CALDIST('28.1','72.3',
latitude||','||longitude) as dist FROM LOCATION.USER_LOCATIONS_LATEST

but it is giving exception for query with where clause

select latitude, longitude, CALDIST('28.1','72.3',
latitude||','||longitude) as dist FROM LOCATION.USER_LOCATIONS_LATEST where
CALDIST('28.1','72.3', latitude||','||longitude) > 700.0

and exception is

java.util.concurrent.ExecutionException:
org.apache.phoenix.schema.TypeMismatchException: ERROR 203 (22005): Type
mismatch. ERROR 203 (22005): Type mismatch. DOUBLE cannot be coerced to
VARCHAR
at java.util.concurrent.FutureTask.report(FutureTask.java:122)
at java.util.concurrent.FutureTask.get(FutureTask.java:192)
at
org.apache.phoenix.iterate.BaseResultIterators.close(BaseResultIterators.java:802)
at
org.apache.phoenix.iterate.BaseResultIterators.getIterators(BaseResultIterators.java:739)
at
org.apache.phoenix.iterate.BaseResultIterators.getIterators(BaseResultIterators.java:638)
at
org.apache.phoenix.iterate.RoundRobinResultIterator.getIterators(RoundRobinResultIterator.java:176)
at
org.apache.phoenix.iterate.RoundRobinResultIterator.next(RoundRobinResultIterator.java:91)
at org.apache.phoenix.jdbc.PhoenixResultSet.next(PhoenixRe


Thanks,
Suyash

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