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

by patcat88 (Deacon)
on Nov 03, 2011 at 22:30 UTC ( #935790=note: print w/replies, xml ) Need Help??

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

Hmmmm. Not an Perl OLE expert, but, it seems GetPrecursorInfoFromScanNum returns a Variant array of C structs, not an variant array of integers according to the manual. Every example in the manual is C/C++, zero VB. Is your
"Output: $VAR1 = [ '414.005279541016', '1.83302424514875e-307', '3.50253979763967e-310', '1.36817960845299e-312', '2.68156223007842e+154',
even valid compared to Thermo's official viewer for the file?

I think you need to try to get perl OLE to return an array of string, the strings will be binary garbage but should be 8+8+4+4 bytes long, then do an "unpack('FFll',$arr[$i]);" on it to decode the C struct. Try looking for Visual Basic code for your control and see how its done there.
typedef struct tagMS_PrecursorInfo { double dMonoIsoMZ; double dIsolationMZ; long nChargeState; long nScanNumber; } MS_PrecursorInfo;
I pulled that from the IDL inside your control. Its described the same way in manual page for GetPrecursorInfoFromScanNum. Can you point me to a sample raw file for this control?

Edit, try changing "my $arr = Variant( VT_VARIANT | VT_BYREF);" to " my $arr = Variant( VT_ARRAY | VT_BYREF);"

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Re^2: Getting mixed real and integer data out of Win32::OLE Safearray
by nikosv (Chaplain) on Nov 04, 2011 at 09:15 UTC

    A safearray can only hold one type at a time which means that it can either be an array of integers or an array of reals.

    To bypass that you can make an array of Variants. A Variant in essense is a discriminated union and wraps the actual type, thus in an array of Variants you can have mixed data types.

     my $array_size = Win32::OLE::Variant->new(VT_I4|VT_BYREF, 20);

    is not correct since this is asking for an array of Ints

    I would go for :   my $arr = Variant( VT_VARIANT | VT_ARRAY, 25);
    it's 25 elements right?

    and also I don't think that you can combine VT_ARRAY with VT_BYREF.

    After you get the array of Variants back you can iterate through the elements and check their underlying type with the Type() method and then go on to extract the values

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