H3 - add function h3ToGeo

This commit is contained in:
bharatnc 2021-06-01 16:42:56 -07:00
parent e5f49477a6
commit e96f23d46b
2 changed files with 104 additions and 0 deletions

102
src/Functions/h3toGeo.cpp Normal file
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@ -0,0 +1,102 @@
#if !defined(ARCADIA_BUILD)
# include "config_functions.h"
#endif
#if USE_H3
#include <array>
#include <math.h>
#include <Columns/ColumnArray.h>
#include <Columns/ColumnTuple.h>
#include <Columns/ColumnsNumber.h>
#include <DataTypes/DataTypeTuple.h>
#include <DataTypes/DataTypesNumber.h>
#include <Functions/FunctionFactory.h>
#include <Functions/IFunction.h>
#include <Common/typeid_cast.h>
#include <ext/range.h>
#include <h3api.h>
namespace DB
{
namespace ErrorCodes
{
extern const int ILLEGAL_TYPE_OF_ARGUMENT;
extern const int ILLEGAL_COLUMN;
}
namespace
{
/// Implements the function h3ToGeo which takes a single argument (h3Index)
/// and returns the latitude and longitude that correspond to the provided h3 index
class FunctionH3ToGeo : public IFunction
{
public:
static constexpr auto name = "H3ToGeo";
static FunctionPtr create(ContextConstPtr) { return std::make_shared<FunctionH3ToGeo>(); }
std::string getName() const override { return name; }
size_t getNumberOfArguments() const override { return 1; }
bool useDefaultImplementationForConstants() const override { return true; }
DataTypePtr getReturnTypeImpl(const DataTypes & arguments) const override
{
const auto * arg = arguments[0].get();
if (!WhichDataType(arg).isUInt64())
throw Exception(
"Illegal type " + arg->getName() + " of argument " + std::to_string(1) + " of function " + getName() + ". Must be UInt64",
ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);
return std::make_shared<DataTypeTuple>(
DataTypes{std::make_shared<DataTypeFloat64>(), std::make_shared<DataTypeFloat64>()},
Strings{"latitude", "longitude"});
}
ColumnPtr executeImpl(const ColumnsWithTypeAndName & arguments, const DataTypePtr &, size_t input_rows_count) const override
{
const auto * col_index = arguments[0].column.get();
auto dst = ColumnVector<Float64>::create();
auto & dst_data = dst->getData();
dst_data.resize(input_rows_count);
ColumnPtr res_column;
auto latitude = ColumnFloat64::create(input_rows_count);
auto longitude = ColumnFloat64::create(input_rows_count);
ColumnFloat64::Container & lon_data = longitude->getData();
ColumnFloat64::Container & lat_data = latitude->getData();
for (const auto row : ext::range(0, input_rows_count))
{
const UInt64 h3Index = col_index->getUInt(row);
GeoCoord coord;
h3ToGeo(h3Index,&coord);
lon_data[row] = coord.lon;
lat_data[row] = coord.lat;
}
MutableColumns result;
result.emplace_back(std::move(latitude));
result.emplace_back(std::move(longitude));
return ColumnTuple::create(std::move(result));
}
};
}
void registerFunctionH3ToGeo(FunctionFactory & factory)
{
factory.registerFunction<FunctionH3ToGeo>();
}
}
#endif

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@ -28,6 +28,7 @@ void registerFunctionSvg(FunctionFactory & factory);
#if USE_H3
void registerFunctionGeoToH3(FunctionFactory &);
void registerFunctionH3ToGeo(FunctionFactory &);
void registerFunctionH3EdgeAngle(FunctionFactory &);
void registerFunctionH3EdgeLengthM(FunctionFactory &);
void registerFunctionH3GetResolution(FunctionFactory &);
@ -66,6 +67,7 @@ void registerFunctionsGeo(FunctionFactory & factory)
#if USE_H3
registerFunctionGeoToH3(factory);
registerFunctionH3ToGeo(factory);
registerFunctionH3EdgeAngle(factory);
registerFunctionH3EdgeLengthM(factory);
registerFunctionH3GetResolution(factory);