% Insert the code fragments below into your version of parcel.m
% Existing code in parcel.m is shown for reference.
%----start---------------------------------------------      
      CAPE = 0;
%----end-----------------------------------------------      

%     DO ASCENT

%      while (p > ptop)
      while (z < ztop)

      i = i + 1;  
      z = z + dz;

%-----start--------------------------------------------      
%     for CAPE: save T, Te, p from previous level
      T1 = T;
      Te1 = Te;
      p1 = p;     
%-----end----------------------------------------------      
%     environment T, p (US Standard Atmosphere)

      [Te pe] = TP_std ( z );      
      p = pe;

==================================================
(code omitted)
==================================================

%     display  values       
%     disp ( [p_mb(i) th_K(1) T_C(i) qv_gkg(i) qc_gkg(i)] )

%-----start--------------------------------------------      
      dCAPE =  rgas * ( T - Te + T1 - Te1 ) / 2 * log(p1/p);
      CAPE = CAPE + max(0, dCAPE);

%     LFC: dCAPE becomes > 0
      if T1-Te1 < 0 && T-Te > 0 
          LFC = (p1 + p) / 2 / pa_per_mb
      end
%     LNB: dCAPE becomes < 0
      if T1-Te1 > 0 && T-Te < 0 
          LNB = (p1 + p) / 2 / pa_per_mb
      end
      
%      disp ( [ p_mb(i) CAPE dCAPE T-Te ] )
%-----end----------------------------------------------      
       
      end
%-----start--------------------------------------------           
      CAPE
      wmax = sqrt(2*CAPE)
%-----end----------------------------------------------