Matlab return C call by reference

I am using a compiled C DLL library to compute various astronomical functions, for example time since epoch and ra/dec to az/el conversions. I figured out how to call these functions from Python, but Matlab is another matter. The call is of this form:

time_since_1950 = TimeFunc.TimeComps(c_int(year), c_int(dayOfYear), c_int(hour), c_int(minute), c_double(seconds));
Astro.RaDecToAzEl(c_double(time_since_1950), c_double(float(lat)), c_double(float(lon)), ...
    c_double(RA), c_double(dec), byref(az), byref(el));

There are several issues here:

1. Dot indexing is not supported for function calls
2. c_int and c_double typecasting are not supported. Can I just replace these with Matlab int32 and double?
3. RaDecToAzEl returns az and el by reference. I don't know how to make this work.

I have already defined my Matlab input arguments as int32 and double, as appropriate.

Is there a way to make this work with the existing C libraries?

[dpb]

I wonder if the following will be of any use ... <cpp-interface>

[Kurt]

I'll take a look. Thanks

Answer 1

[Kurt]

The solution was to first load my Dynamic Link Libraries (DLLs).

Then the Matlab calls to my library functions look like this:

time_since_1950 = calllib('TimeFunc','TimeComps', year, dayOfYear, hour, minute, seconds);
azPtr = libpointer('doublePtr', az);
elPtr = libpointer('doublePtr', el);
calllib('Astro','RaDecToAzEl',time_since_1950, lat, lon, RA, dec, azPtr, elPtr);
az = azPtr.Value;
el = elPtr.Value;

Turns out, Matlab really CAN work with pointers to and from C code.