PRO Respint, f, c                 ;f=flux, or df/da, c=countrate or dc/da
   
   COMMON Rsp, nch, nsc, esc, rsc   ;characteristics of the detector
   
   c = rsc#f            ;just a quick matrix multiplication
   ;so the first dimension of f must be nsc
   ;f=f(nsc,anything)
   RETURN
END