2.1.18.9 ocmath_gridding_weighted_average

Description

This gridding function search neighborhood data points within specified radius. And then estimate the grid point value by weighted averaged method.

Syntax

int ocmath_gridding_weighted_average( int nSize, const double * pX, const double * pY, const double * pZ, int nOutSize, const double * pXout, const double * pYout, double * pZout, double dRadius, int nMethod = WEIGHTED_AVERAGE_SQUARE )

Parameters

nSize

[input] the size of the input data

pX

[input] double pointer to the array which specify the x-coordinate of the raw data.

pY

[input] double pointer to the array which specify the y-coordinate of the raw data.

pZ

[input] double pointer to the array which specify the responded z-value of the raw data.

nOutSize

[input] the size of the output data.

pXout

[input] double pointer to the array which specify the x-coordinate of the grid.

pYout

[input] double pointer to the array which specify the y-coordinate of the grid.

pZout

[output] double pointer to the array the get the value of the grid.

dRadius

[input] searching radius, points within the area will be used for counting the gridding value.

nMethod

[input] specify the method used for counting the weight.

Return

Returns OE_NOERROR if succeed, error codes otherwise.

Examples

EX1

//Suppose you have an active worksheet with three columns which are designated as XYZ.
#include <wks2mat.h>
#define NUM_ROWS 11
#define NUM_COLS 11
int ocmath_gridding_weighted_average_ex1(double dRadius, int nMethod)
{
    Worksheet wks=Project.ActiveLayer();

    Dataset dx(wks, 0), dy(wks, 1), dz(wks, 2);
    vector<double> vx = dx, vy = dy, vz = dz;
    double dxMin, dxMax;
    double dyMin, dyMax;
    vx.GetMinMax(dxMin, dxMax);
    vy.GetMinMax(dyMin, dyMax);
    
    MatrixLayer ml;
    ml.Create();
    MatrixObject mo = ml.MatrixObjects(0);
    mo.SetXY(dxMin, dyMin, dxMax, dyMax);
    mo.SetNumCols(NUM_COLS);
    mo.SetNumRows(NUM_ROWS);
    matrix& mat = mo.GetDataObject();

    vector vXGrid(NUM_ROWS * NUM_COLS), vYGrid(NUM_ROWS * NUM_COLS);
    int iRet = ocmath_mat_to_regular_xyz(NULL, NUM_ROWS, NUM_COLS, dxMin, dxMax, dyMin, dyMax, vXGrid, vYGrid, NULL);
    if (iRet <= 0) { 
        printf("Thin plate spline: failed to create XY gridding!\n");
        return false;
    }
    
    ocmath_gridding_weighted_average(
                    vx.GetSize(),vx, vy, vz, 
                    NUM_ROWS * NUM_COLS, vXGrid, vYGrid, mat, 
                    dRadius, nMethod);
    return 0;
}

Remark

See Also

Header to Include

wks2mat.h

Reference