mirror of
https://github.com/ClickHouse/ClickHouse.git
synced 2024-12-04 21:42:39 +00:00
96 lines
2.9 KiB
C++
96 lines
2.9 KiB
C++
#if !defined(ARCADIA_BUILD)
|
|
# include "config_functions.h"
|
|
#endif
|
|
|
|
#if USE_H3
|
|
|
|
#include <Columns/ColumnsNumber.h>
|
|
#include <DataTypes/DataTypesNumber.h>
|
|
#include <Functions/FunctionFactory.h>
|
|
#include <Functions/IFunction.h>
|
|
#include <IO/WriteHelpers.h>
|
|
#include <Common/typeid_cast.h>
|
|
#include <base/range.h>
|
|
|
|
#include <constants.h>
|
|
#include <h3api.h>
|
|
|
|
|
|
namespace DB
|
|
{
|
|
namespace ErrorCodes
|
|
{
|
|
extern const int ILLEGAL_TYPE_OF_ARGUMENT;
|
|
extern const int ARGUMENT_OUT_OF_BOUND;
|
|
}
|
|
|
|
namespace
|
|
{
|
|
|
|
// Average metric edge length of H3 hexagon. The edge length `e` for given resolution `res` can
|
|
// be used for converting metric search radius `radius` to hexagon search ring size `k` that is
|
|
// used by `H3kRing` function. For small enough search area simple flat approximation can be used,
|
|
// i.e. the smallest `k` that satisfies relation `3 k^2 - 3 k + 1 >= (radius / e)^2` should be
|
|
// chosen
|
|
class FunctionH3EdgeLengthM : public IFunction
|
|
{
|
|
public:
|
|
static constexpr auto name = "h3EdgeLengthM";
|
|
|
|
static FunctionPtr create(ContextPtr) { return std::make_shared<FunctionH3EdgeLengthM>(); }
|
|
|
|
std::string getName() const override { return name; }
|
|
|
|
size_t getNumberOfArguments() const override { return 1; }
|
|
bool useDefaultImplementationForConstants() const override { return true; }
|
|
bool isSuitableForShortCircuitArgumentsExecution(const DataTypesWithConstInfo & /*arguments*/) const override { return false; }
|
|
|
|
DataTypePtr getReturnTypeImpl(const DataTypes & arguments) const override
|
|
{
|
|
const auto * arg = arguments[0].get();
|
|
if (!WhichDataType(arg).isUInt8())
|
|
throw Exception(
|
|
ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT,
|
|
"Illegal type {} of argument {} of function {}. Must be UInt8",
|
|
arg->getName(), 1, getName());
|
|
|
|
return std::make_shared<DataTypeFloat64>();
|
|
}
|
|
|
|
ColumnPtr executeImpl(const ColumnsWithTypeAndName & arguments, const DataTypePtr &, size_t input_rows_count) const override
|
|
{
|
|
const auto * col_hindex = arguments[0].column.get();
|
|
|
|
auto dst = ColumnVector<Float64>::create();
|
|
auto & dst_data = dst->getData();
|
|
dst_data.resize(input_rows_count);
|
|
|
|
for (const auto row : collections::range(0, input_rows_count))
|
|
{
|
|
const UInt64 resolution = col_hindex->getUInt(row);
|
|
if (resolution > MAX_H3_RES)
|
|
throw Exception(
|
|
ErrorCodes::ARGUMENT_OUT_OF_BOUND,
|
|
"The argument 'resolution' ({}) of function {} is out of bounds because the maximum resolution in H3 library is ",
|
|
resolution, getName(), MAX_H3_RES);
|
|
|
|
Float64 res = getHexagonEdgeLengthAvgM(resolution);
|
|
|
|
dst_data[row] = res;
|
|
}
|
|
|
|
return dst;
|
|
}
|
|
};
|
|
|
|
}
|
|
|
|
void registerFunctionH3EdgeLengthM(FunctionFactory & factory)
|
|
{
|
|
factory.registerFunction<FunctionH3EdgeLengthM>();
|
|
}
|
|
|
|
}
|
|
|
|
#endif
|