Getting mixed real and integer data out of Win32::OLE Safearray

[Halligan]

We are trying to use a vendor provided .dll file to extract data from a binary file. Below is sample code and output as well as the vendor’s documentation. The call is supposed to return a Safearray that contains both real and integer values (2 each). What we get back seems to be an array with 23 real values of which seem to match the expected real values in positions 0 and 8 and the first integer at 17 (close should be 2). We are still missing the last integer value (which we need). What is the method to get both real and integer value out of the same Perl array? Thanks.

Brian D. Halligan, Ph.D.

Biotechnology and Bioengineering Center

Medical College of Wisconsin

8701 Watertown Plank Road

Milwaukee, WI 53226

Sample Code:

 
use Win32::OLE;
use Win32::OLE::Variant qw(:DEFAULT nothing);
use Data::Dumper;

                my $filename = $ARGV[0];
                Win32::OLE->Option( Warn => 3 );
                my $open_raw_file = eval{
                                Win32::OLE->new('MSFileReader.XRawfile
+.1', sub{ $_[0]->Close } );
                }; # eval
                if($@){
                                warn "Could not create XRawfile object
+.$@\nThis function requires Thermo MSFileReader\n";
                } # if
                $open_raw_file->Open($filename);
                $open_raw_file->SetCurrentController( 0, 1 ); # mass s
+pec device, first MS device
                my $scan_num = 1001; # arbitrary scan number
                my $arr = Variant( VT_VARIANT | VT_BYREF);
                my $array_size = Win32::OLE::Variant->new(VT_I4|VT_BYR
+EF, 20);
                $open_raw_file->GetPrecursorInfoFromScanNum($scan_num,
+ $arr, $array_size);
                my @values =  @{$arr->Value};
                print Dumper \@values;
                print "Array size is $array_size\n";
                exit;

Output:

$VAR1 = [
          '414.005279541016',
          '1.83302424514875e-307',
          '3.50253979763967e-310',
          '1.36817960845299e-312',
          '2.68156223007842e+154',
          '9.96719496044929e-206',
          '-7.16479736258273e+154',
          '1.1404242820188e+279',
          '414.005218505859',
          '1.20129076821422e-302',
          '1.74092514125002e-309',
          '6.80048883300789e-312',
          '2.65644095020843e-314',
          '-4.09173827895217e+149',
          '4.97033753286898e-290',
          '5.38341844184884e-309',
          '2.10289782884708e-311',
          '2.00000738352537',
          '7.64529567303078e-298',
          '2.34086864460609e-289',
          '5.57490734202886e-309',
          '4.95144931563519e+173',
          '5.83291545534861e-302',
          '4.11480344154759e-270'
        ];
Array size is 1


Vendor Documentation:

GetPrecursorInfoFromScanNum
                                HRESULT GetPrecursorInfoFromScanNum(lo
+ng nScanNumber,
                                VARIANT* pvarPrecursorInfos,
                                LONG* pnArraySize)
                                Return Value
                                0 if successful; otherwise, see Error 
+Codes.
                Parameters
                                nScanNumber The scan number for which 
+the corresponding precursor info is to be returned.
                                pvarPrecursorInfos A valid pointer to 
+a VARIANT variable to receive the precursor info.
                                pnArraySize A valid pointer to a long 
+variable to receive the number of precursor info packets
                                returned in the precursor info array.
                Remarks
                                This function is used to retrieve info
+rmation about the parent scans of a data dependent MSn scan.
                                You will retrieve the scan number of t
+he parent scan, the isolation mass used, the charge state and the
                                monoisotopic mass as determined by the
+ instrument firmware. You will also get access to the scan data
                                of the parent scan in the form of a XS
+pectrumRead object.
                                For the charge state and the monoisoto
+pic mass it is tried to further refine these values from the actual
                                parent scan data.
                Example
                                struct PrecursorInfo
                                                {
                                                double dIsolationMass;
                                                double dMonoIsoMass;
                                                long nChargeState;
                                                long nScanNumber;
                                                };
                                void CTestOCXDlg::OnOpenParentScansOcx
+()
                                                {
                                                try
                                                {
                                VARIANT vPrecursorInfos;
                                VariantInit(&vPrecursorInfos);
                                long nPrecursorInfos = 0;
                                // Get the precursor scan information
                                2 Function Reference
                                GetPrecursorInfoFromScanNum
                                Thermo Scientific MSFileReader User Gu
+ide (XRawfile2.dll) 197
                                m_Rawfile.GetPrecursorInfoFromScanNum(
+m_nScanNumber,
                                                &vPrecursorInfos,
                                                &nPrecursorInfos);
                                // Access the safearray buffer
                                BYTE* pData;
                                SafeArrayAccessData(vPrecursorInfos.pa
+rray, (void**)&pData);
                                for (int i=0; i < nPrecursorInfos; ++i
+)
                                                {
                                                // Copy the scan infor
+mation from the safearray buffer
                                                PrecursorInfo info;
                                                memcpy(&info,
                                                pData + i * sizeof(MS_
+PrecursorInfo),
                                                sizeof(PrecursorInfo))
+;
                                                // Process the paraent
+ scan information ...
                                                }
                                SafeArrayUnaccessData(vPrecursorInfos.
+parray);
                                }
                                catch (...)
                                                {
                                                AfxMessageBox(_T("Ther
+e was a problem while getting the parent scan
                                                information."));
                                                }