call IO_writeIntegralQuantities(integer(in) :: isFirst, real(in) :: simTime)
Compute the values of integral quantities (eg. total energy) and write them to an ASCII file. If this is the initial step, create the file and write a header to it before writing the data. Presently, this supports 1, 2, and 3-d Cartesian geometry and 2-d cylindrical geometry (r,z). More geometries can be added by modifying the volume of each zone (dvol). Users should modify this routine if they want to store any quantities other than default values in the flash.dat. Make sure to modify the nGlobalSum parameter to match the number of quantities written. Also make sure to modify the header to match the names of quantities with those calculated in the lsum and gsum arrays.
isFirst - if 1 then write header info plus data, otherwise just write data simTime - simulation time