2.1.23.2.16 ocmath_test_peaks_by_number

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

Description

Find the npeakNum highest peaks.

Syntax

int ocmath_test_peaks_by_number( int nSize, double * pXPeaks, double * pYPeaks, int * pnIndices, int npeakNum )

Parameters

nSize: [input] size of pXPeaks, pYPeaks, pnIndices;
pXPeaks: [modify] Its size is nSize. on input, it contains all peaks' X coordinate's datas; on output, it contains X coordinate's datas of the right peaks needed by user, if number of the right peaks is less than nSize, fill the excrescent elements of it with NANUM.
pYPeaks: [modify] Its size is nSize. on input, it contains all peaks' Y coordinate's datas; on output, it contains y coordinate's datas of the right peaks needed by user, if number of the right peaks is less than nSize, fill the excrescent elements of it with NANUM.
pnIndices: [modify] Its size is nSize. On input, it contains all peaks' indices; on output, it contains indices of the right peaks needed by user, and if number of the right peaks is less than nSize, fill the excrescent elements of it with 0.
npeakNum: [input] the number of peaks needed by user

Return

Return OE_NOERROR if succeed, otherwise, non-zero error code is returned.

Examples

EX1

//Assume in the current graph, curve's XY data is in the first data plot. This piece
//of code get the XY data of the curve from the first data plot, use  
//ocmath_find_peaks_1st_derivative to find the curve's peaks and then test the peaks.
//The result is output in a new worksheet and the peaks will plot in the original 
//data plot.
void ocmath_test_peaks_by_number_ex1( )
{
    GraphLayer gl = Project.ActiveLayer();
    if (!gl)
    {
        return;
    }
 
    //get data from the first dataplot
    DataPlot dp = gl.DataPlots(0);        
    DataRange dr;
    vector vxData, vyData;
    if(dp.GetDataRange(dr))
    {
        DWORD dwPlotID;
        if(dr.GetData(DRR_GET_DEPENDENT | DRR_NO_FACTORS, 0, &dwPlotID, NULL, &vyData, &vxData) < 0)
        {
            printf("get_plot_data failed GetData");
            return;
        }
    }
 
    uint nDataSize = vxData.GetSize();
 
    vector vxPeaks, vyPeaks;
    vector<int> vnIndices;
 
    vxPeaks.SetSize(nDataSize);
    vyPeaks.SetSize(nDataSize);
    vnIndices.SetSize(nDataSize);
	
    //Find curve's peaks by 1st derivative. 
    ocmath_find_peaks_1st_derivative( &nDataSize, vxData, vyData, vxPeaks, vyPeaks, vnIndices, POSITIVE_DIRECTION | NEGATIVE_DIRECTION,11);
    
    vxPeaks.SetSize(nDataSize);
    vyPeaks.SetSize(nDataSize);
    vnIndices.SetSize(nDataSize);
    int peakNum=10;
    int nRet = ocmath_test_peaks_by_number(nDataSize, vxPeaks, vyPeaks, vnIndices, peakNum);
    if( nRet < OE_NOERROR )
    {
        printf("error code: %d\n", nRet);
        return;
    }
    vxPeaks.SetSize(peakNum);
    vyPeaks.SetSize(peakNum);
    vnIndices.SetSize(peakNum);
    
    //new a worksheet to output the result
    WorksheetPage wksPage;
    wksPage.Create();
    Worksheet wksResult = wksPage.Layers(0);
    int nIndCol, nXCol, nYCol;
    nIndCol = wksResult.AddCol("Indices");
    nXCol = wksResult.AddCol("X Coordinate");
    nYCol = wksResult.AddCol("Y Coordinate");
    wksResult.Columns(nIndCol).SetType(OKDATAOBJ_DESIGNATION_X);
    wksResult.Columns(nXCol).SetType(OKDATAOBJ_DESIGNATION_X);
    wksResult.Columns(nYCol).SetType(OKDATAOBJ_DESIGNATION_Y);
    
    DataRange drOut;
    drOut.Add("X", wksResult, 0, nIndCol, -1, nIndCol);
    drOut.Add("Y", wksResult, 0, nXCol, -1, nXCol);
    drOut.Add("Z", wksResult, 0, nYCol, -1, nYCol);
    drOut.SetData(&vyPeaks, &vxPeaks, &vnIndices);
    
    //plot the peaks in the data plot
    XYRange plotRange;
    plotRange.Add("X", wksResult, 0, nXCol, -1, nXCol);
    plotRange.Add("Y", wksResult, 0, nYCol, -1, nYCol);
    gl.AddPlot(plotRange, IDM_PLOT_SCATTER);
}

Remark

Find npeakNum highest peaks depending on the abs of points y value.

In other words, find npeakNum peaks, whose y value's abs is greatest in the residual peaks.

Then, nPeakNum records the number of peaks passed the testing, pXPeaks and pYPeaks contain X and Y coordinate's datas of peaks passed the testing, pnIndices contains the indices of peaks passed testing.