The file include.h sets a variety of options including several compiler dependent options. You may need to edit include.h to get the options you require. If you are using a compiler different from one I have worked with you may have to set up a new section in include.h appropriate for your compiler.
Borland, Turbo, Gnu, Microsoft, Watcom and Zortech are recognised automatically. If none of these are recognised a default set of options is used. These are fine for AT&T, HPUX and Sun C++. If you using a compiler I don't know about you may have to write a new set of options.
Activate the appropriate statement to make the element type float or double.
If you are using the standard style for deleting arrays (AT&T version 2.1 or later) make sure Version21 is #defined. If you are using the old style, make sure it is not #defined.
There is an option in include.h for selecting whether you use compiler supported exceptions, simulated exceptions, or disable exceptions. Use the option for compiler supported exceptions if and only if you have set the option on your compiler to recognise exceptions. Disabling exceptions sometimes helps with compilers that are incompatible with my exception simulation scheme.
I suggest you leave the option TEMPS_DESTROYED_QUICKLY activated, even though the Gnu compiler is the only one I know about that requires it. This stores the trees dsecribing matrix expressions on the heap rather than the stack and, surprisingly, seems to give better performance. See the discussion in newmatb.txt for more explanation.
Leave the option TEMPS_DESTROYED_QUICKLY_R not activated unless you are using the Gnu G++ compiler. This option controls whether the ReturnMatrix construct uses the stack or the heap. The heap version is rather kludgy and probably should be avoided where possible.
The option DO_FREE_CHECK is used for tracking memory leaks and normally should not be activated.
Activate SETUP_C_SUBSCRIPTS if you want to use traditional C style element access.