ocmath_test_peaks_by_number

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;
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);
}


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.