void test()
{
	int importnum = 366;
	int timewindow = 15;
	int ananum = 24 * 60 / timewindow;
	int anawidth = timewindow * 60 / 10;	
        double dDate;
	Worksheet wRes("anaresults"); // declare results wks
	Worksheet wFiles("importfiles"); // declare file list wks
	Worksheet wks; // declare import wks
	wks.Create(NULL,CREATE_TEMP); // create as temporary, will be destroyed when done
	//wks.Columns(0).SetFormat(OKCOLTYPE_TIME);
	//wks.Columns(0).SetSubFormat(3);
	Dataset dd(wks,1); // declare 2nd column of import wks as dataset
	Dataset dRes(wRes,1); // declare 2nd column of results wks as dataset
	vector v1,v2; // declare two temporary vectors
	string sFileName;
	matrix mm(ananum, anawidth); // declare matrix with ananum rows, anawidth columns
	for(int i=0; i<importnum; i++)
	{
		dDate = wFiles.Cell(i,0); // get date from file list wks
		sFileName = "p" + get_date_str(dDate, LDF_YYMMDD); // convert to file name
		if( import_one_file(wks, sFileName) )
		{
			wks.DeleteRange(0,0,4,wks.GetNumCols()-1); // delete rows 1-5
			mm.SetByVector(dd); // fill matrix row-wise from column 2
			mm.GetColumn(v1,0); // first column to vector v1 (bigindata)
			mm.GetColumn(v2,anawidth-1); // last column to vector v2 (enddata)
			v2 -= v1; // subtract v1 from v2 (gradient)
			dRes.Append(v2); // append v2 to results wks
		}
	}
}

bool import_one_file(Worksheet wks, string sFileName)
{
	string sDataPath = "h:\\Datafiles\\data\\";
	ASCIMP	ascimp;
	if( AscImpReadFileStruct(sDataPath + sFileName + ".csv", &ascimp)==0 )
	{
		if( wks.ImportASCII(sFileName, ascimp)==0 )
			return true;
	}
	return false;
}