Examples with Description com.facebook.presto.spi.function.Description used on opensource projects

Example 36 with Description

use of com.facebook.presto.spi.function.Description in project presto by prestodb.

the class MathFunctions method inverseCauchyCdf.

@Description("Inverse of Cauchy cdf for a given probability, median, and scale (gamma)")
@ScalarFunction
@SqlType(StandardTypes.DOUBLE)
public static double inverseCauchyCdf(@SqlType(StandardTypes.DOUBLE) double median, @SqlType(StandardTypes.DOUBLE) double scale, @SqlType(StandardTypes.DOUBLE) double p) {
    checkCondition(p >= 0 && p <= 1, INVALID_FUNCTION_ARGUMENT, "p must be in the interval [0, 1]");
    checkCondition(scale > 0, INVALID_FUNCTION_ARGUMENT, "scale must be greater than 0");
    CauchyDistribution distribution = new CauchyDistribution(null, median, scale, CauchyDistribution.DEFAULT_INVERSE_ABSOLUTE_ACCURACY);
    return distribution.inverseCumulativeProbability(p);
}

Example 37 with Description

use of com.facebook.presto.spi.function.Description in project presto by prestodb.

the class JoniRegexpFunctions method regexpSplit.

@ScalarFunction
@LiteralParameters("x")
@Description("returns array of strings split by pattern")
@SqlType("array(varchar(x))")
public static Block regexpSplit(@SqlType("varchar(x)") Slice source, @SqlType(JoniRegexpType.NAME) Regex pattern) {
    Matcher matcher = pattern.matcher(source.getBytes());
    BlockBuilder blockBuilder = VARCHAR.createBlockBuilder(null, 32);
    int lastEnd = 0;
    int nextStart = 0;
    int offset = getMatchingOffset(matcher, nextStart, source.length());
    if (offset == -1) {
        VARCHAR.writeSlice(blockBuilder, source);
        return blockBuilder.build();
    }
    do {
        if (matcher.getEnd() == matcher.getBegin()) {
            nextStart = matcher.getEnd() + 1;
        } else {
            nextStart = matcher.getEnd();
        }
        VARCHAR.writeSlice(blockBuilder, source, lastEnd, matcher.getBegin() - lastEnd);
        lastEnd = matcher.getEnd();
        offset = getMatchingOffset(matcher, nextStart, source.length());
    } while (offset != -1);
    VARCHAR.writeSlice(blockBuilder, source.slice(lastEnd, source.length() - lastEnd));
    return blockBuilder.build();
}

Example 38 with Description

use of com.facebook.presto.spi.function.Description in project presto by prestodb.

the class QuantileDigestFunctions method valuesAtQuantilesReal.

@ScalarFunction("values_at_quantiles")
@Description("For each input q between [0, 1], find the value whose rank in the sorted sequence of the n values represented by the qdigest is qn.")
@SqlType("array(real)")
public static Block valuesAtQuantilesReal(@SqlType("qdigest(real)") Slice input, @SqlType("array(double)") Block percentilesArrayBlock) {
    QuantileDigest digest = new QuantileDigest(input);
    BlockBuilder output = REAL.createBlockBuilder(null, percentilesArrayBlock.getPositionCount());
    for (int i = 0; i < percentilesArrayBlock.getPositionCount(); i++) {
        REAL.writeLong(output, floatToRawIntBits(sortableIntToFloat((int) digest.getQuantile(DOUBLE.getDouble(percentilesArrayBlock, i)))));
    }
    return output.build();
}

Example 39 with Description

use of com.facebook.presto.spi.function.Description in project presto by prestodb.

the class QuantileDigestFunctions method quantileAtValueBigint.

@ScalarFunction("quantile_at_value")
@Description("Given an input x between min/max values of qdigest, find which quantile is represented by that value")
@SqlType(StandardTypes.DOUBLE)
@SqlNullable
public static Double quantileAtValueBigint(@SqlType("qdigest(bigint)") Slice input, @SqlType(StandardTypes.BIGINT) long value) {
    QuantileDigest digest = new QuantileDigest(input);
    if (digest.getCount() == 0 || value > digest.getMax() || value < digest.getMin()) {
        return null;
    }
    double bucketCount = digest.getHistogram(ImmutableList.of(value)).get(0).getCount();
    return bucketCount / digest.getCount();
}

Example 40 with Description

use of com.facebook.presto.spi.function.Description in project presto by prestodb.

the class QuantileDigestFunctions method valuesAtQuantilesDouble.

@ScalarFunction("values_at_quantiles")
@Description("For each input q between [0, 1], find the value whose rank in the sorted sequence of the n values represented by the qdigest is qn.")
@SqlType("array(double)")
public static Block valuesAtQuantilesDouble(@SqlType("qdigest(double)") Slice input, @SqlType("array(double)") Block percentilesArrayBlock) {
    QuantileDigest digest = new QuantileDigest(input);
    BlockBuilder output = DOUBLE.createBlockBuilder(null, percentilesArrayBlock.getPositionCount());
    for (int i = 0; i < percentilesArrayBlock.getPositionCount(); i++) {
        DOUBLE.writeDouble(output, sortableLongToDouble(digest.getQuantile(DOUBLE.getDouble(percentilesArrayBlock, i))));
    }
    return output.build();
}