namespace geospatial

// namespaces

namespace xf::data_analytics::geospatial::internal

knn

#include "xf_data_analytics/geospatial/knn.hpp"

template <
    int CSV_PU_NUM = 2,
    int MAX_SORT_NUM = 8
    >
void knn (
    ap_uint <128>* csv_buf,
    ap_uint <8>* schema,
    float base_x,
    float base_y,
    int k,
    float* sorted_dist_buf,
    uint32_t* sorted_idx_buf
    )

K Nearest Neighbors(KNN): find nearest-K points for a given base point.

Parameters:

CSV_PU_NUM	num of csv parser core used to parallel parse csv data, only support 2/4/8
MAX_SORT_NUM	the max number of the sequence can be sorted, should be less than 1024
csv_buf	input csv data
schema	input csv schema
base_x	base point x coordinate
base_y	base point y coordinate
k	num of nearest point, k <= MAX_SORT_NUM
sorted_dist_buf	output distance of nearest-K points
sorted_idx_buf	output index of nearest-K points

strtreeTop

#include "xf_data_analytics/geospatial/strtree_wrap.hpp"

template <
    typename KT,
    typename VT,
    typename PT,
    typename NT,
    int NC,
    int ISN,
    int BSN,
    int MTCN,
    int MSN
    >
void strtreeTop (
    int sz,
    double* inX,
    double* inY,
    double* inZone,
    PT* extPointBuf0,
    PT* extPointBuf1,
    NT* extNodeBuf0,
    NT* extNodeBuf1,
    NT* extNodeBuf2
    )

strtreeTop strtree (a geospatial index) uses bottom-up way to build an R tree for two-dimensional points

Parameters:

KT	key type
VT	value type
PT	point type
NT	node type
NC	node capacity
ISN	insert sort length
BSN	block sort length
MTCN	merge tree channel number
NSN	max sort length
sz	real size of inX or inY
inX	all x value
inX	all y value
inZone	points (x, y) limit zone
extPointBuf0	output ordered points
extPointBuf1	points buffer
extNodeBuf0	output ordered nodes
extNodeBuf1	nodes buffer
extNodeBuf2	nodes buffer