2.1.17.2.4.2 fit_polyline

1 Description
2 Syntax
3 Parameters
4 Return
5 Examples
6 Remark
7 See Also
8 Header to Included
9 Reference

Description

Fit the curve to a polyline, where n is the number of sections, and get the average of each section optionally

Syntax

bool fit_polyline( int iSize, double * px, double * py, int n, vector & slope, vector & ave = NULL, vector & cutoff = NULL, vector & xave = NULL )

Parameters

iSize: [input] number of input points.
px: [input] X-coordinates of input points.
py: [input] Y-coordinates of input points.
n: [input] Number of segments into which the input data is divided.
slope: [output] Collection of slopes for each segment.
ave: [output] Collection of the average values of Y-coordinates in each segment.
cutoff: [output] Collection of intercepts of each segment.
xave: [output] Collection of the average value of X-coordinates in each segment.

Return

Return TRUE for success, else return FALSE.

Examples

EX1

void fit_polyline_ex()
{
    //import data into new worksheet, user may import this data manully.
    LT_execute("win -t W Origin;");
    LT_execute("open -w %(system.path.program$)Samples\Curve Fitting\Linear Fit.dat;");
    
    Worksheet wks = Project.ActiveLayer();
    if ( wks )
    {
        Column colX(wks, 0);
        Column colY(wks, 1);
        
        vector vX(colX);
        vector vY(colY);
        
        vector vCutoff, vSlope, vAve, vXAve;
        int n = 5;
        int nSize = vX.GetSize();
        
        if ( fit_polyline(nSize, vX, vY, n, vSlope, vAve, vCutoff, vXAve) )
        {
            int nSlopes = vSlope.GetSize();
            for ( int ii = 0; ii < nSlopes; ii++ )
            {
                printf("Slope[%d] = %.4lf\n", ii, vSlope[ii]);
            }
        }
    }
}