convert variant into COleSafeArray in MFC c++

Question

How can I put VARIANT into COleSafeArray? I tried

Variant vara;
COleSafeArray force= vara;

and got "debug assertion failed"

I used a library to convert voltage value to Force value. In Library, there is below function:

VARIANT _Calibration::ConvertToFT(VARIANT* Voltages, LPCTSTR ForceUnits, LPCTSTR TorqueUnits)
{
    VARIANT result;
    static BYTE parms[] =
        VTS_PVARIANT VTS_BSTR VTS_BSTR;
    InvokeHelper(0x60030040, DISPATCH_METHOD, VT_VARIANT, (void*)&result, parms,
        Voltages, ForceUnits, TorqueUnits);
    return result;
}

So in my main program:

COleSafeArray voltagesk;
double voltages[6];
_read-voltage(voltages);
long y;
    for (y = 0; y<6; y++) {
        // COleSafeArrays use pass-by-reference methods to read or write
        voltagesk.PutElement(&y, &(voltages[y]));
    }
COleSafeArray forces = GetActiveCalibration().ConvertToFT(voltagesk, L"lb", L"in-lb");
for (y = 0; y<6; y++) {
        // COleSafeArrays use pass-by-reference methods to read or write
        forces.GetElement(&y, &(voltages[y]));

I tried deleting this line"COleSafeArray forces = GetActiveCalibration().ConvertToFT(voltagesk, L"lb", L"in-lb");", my program ran well, but cannot convert voltage into force so I think that converting from VARIANT to COleSafeArray, has problem

Answer 1

Thanks for your opinions. Actually, this code for purpose converting from voltage into measurement value. voltagesk is not empty because _read-voltage(voltages) put values into voltages. "GetActiveCalibration().ConvertToFT" read calibration info from calibration file and convert voltage into desired value ( following rule of calibration file) I changed my code following:

long y;

Double tempc[6];

_read (voltages);

for (y = 0; y<7; y++) {

    voltagesk.PutElement(&y, &(voltages[y]));
}
VARIANT vara= GetActiveCalibration().ConvertToFT(voltagesk, L"N", L"N-m");

 //returned value type of convertToFT is VARIANT
  COleSafeArray forces;
forces.Create(VT_R8, 1, numElements);
for (y = 0; y<6; y++) 
    {
        forces.PutElement(&y, &vara);
    }
for (y = 0; y<6; y++) {

    forces.GetElement(&y, &tempc[y]); // tempc is the converted value 

    } 

my program ran well, however the converted value is very low ( 2.3333E-1233). I think that type"VT_R8" has a problem in QT. I changed method. Instead using code read calibration file, I read and understand it by myself. After that, I re-wrote my program well and simply for converting purpose without COleSafeArray