function psat=psat(t,const)
  for i=1:rows(const)
    psat(i)=exp(const(i,1)-const(i,2)/(t+const(i,3)));
  end
endfunction

function tsat=tsat(p,const)
  for i=1:rows(const)
    tsat(i)=const(i,2)/(const(i,1)-log(p))-const(i,3);
  end
endfunction

function pbr=pbr(t,x,const)
    psats=psat(t,const);
    p=sum(x.*psats);
    y=x.*psats/p;
    pbr=[y p];
endfunction

x=[0.3,0.7];
ctes=[14.2724,2945.47,224;14.2043,2972.64,209];
res=pbr(75,x,ctes)

function prr=prr(t,y,const)
    psats=psat(t,const);
    p=1/sum(y./psats);
    x=p*y./psats;
    for i=1:length(y)
        prr.(['x',num2str(i)])=x(i);
    end
    prr.('P')=p;
endfunction

ctes=[14.2724,2945.47,224;14.2043,2972.64,209];;
ys=[0.3,0.7];
res=prr(75,ys,ctes)

function tbr=tbr(p,x,const,ref)
    tsats=tsat(p,const);
    tguess=mean(tsats);
    tol=0.001;
    while 1
        psats=psat(tguess,const);
        alfas=psats/psats(ref);
        psatrefn=p/sum(x.*alfas);
        tsatrefn=tsat(psatrefn,const(ref,:));
        if abs(tguess-tsatrefn)<=tol
            break
        else
            tguess=tsatrefn;
        end
    end
    y=x.*psats/p;
    tbr=[y tsatrefn];
endfunction

const=[14.2724,2945.47,224;14.2043,2972.64,209];
xs=[0.6,0.4];
res=tbr(70,xs,const,2)

function trr=trr(p,y,const,ref)
    tsats=tsat(p,const);
    tguess=mean(tsats);
    tol=0.001;
    while 1
        psats=psat(tguess,const);
        alfas=psats/psats(ref);
        psatrefn=p*sum(y./alfas);
        tsatrefn=tsat(psatrefn,const(ref,:));
        if abs(tguess-tsatrefn)<=tol
            break
        else
            tguess=tsatrefn;
        end
    end
    x=p*(y./psats);
    trr=[x tsatrefn];
endfunction

const=[14.2724,2945.47,224;14.2043,2972.64,209];
ys=[0.3,0.7];
res=trr(70,ys,const,1)