# MATLAB: Operands to the || and && operators must be convertible to logical scalar values.

operandsoperators must be logical scalars

I am trying to run a file with given input. the function scripts and
the main files to be run are enclosed belo.I keep geeting errors that says"Operands to the and && operators must be convertible to logical scalar values"
``function [gamma,a]=ACTIVITY_WILSON(MW,rhoL,BIP,T,Z)%This program calculates the activity coefficients (gamma) and the %activities (a) of each component of a mixture of c components using the %Wilson model. %INPUT PARAMETERS: MW: vector (1xc) reporting the molecular weights of the %c components; rhoL, vector (1xc) reporting the liquid density of the c %pure components at temperature T; BIP is a matrix cxc reporting the energy   %interaction parameters (BIP(i,j)=lambda_ij-lambda_ii, J/mol). The energy%interaction parameters are temperature independent; T: temperature of the %system; x vector (1xc) reporting the mole fractions of the components of %the mixture.   %OUTPUT PARAMETERS: gamma: vector 1xc reporting the activity %coefficients of the components of the mixture; a: vector 1xc reporting the %activities of the components of the mixture. %Unless otherwise stated, all input/output parameters are expressed%according to MKS.R=8.314;c=length(Z);%Molar volumes of the pure liquid components composing the mixtureVl=1./((rhoL*1000)./MW);%Lambda terms (dimensionless) of the Wilson formulafor i=1:c    for j=1:c        Lambda(i,j)=(Vl(j)/Vl(i))*exp(-BIP(i,j)/(R*T));    endendfor i=1:c    for j=1:c        A=sum(Z.*Lambda(j,:));        C(j)=Z(j)*Lambda(j,i)/A;    end    lngamma(i)=1-log(sum(Z.*Lambda(i,:)))-sum(C);    gamma(i)=exp(lngamma(i));    a(i)=gamma(i)*Z(i);endend%%function [PD,xDew]=PD_VLE_wilson (C,MW,rhoL,BIP,T,Z)% this is a function that calculates the dewpoint of a mixture with the% wilson correlation for generating activity coefficients for non ideal %liquid phasec=length(Z);for i=1:c     Ps=exp((C(i,1))+(C(i,2)/T)+(C(i,3)*log(T))+(C(i,4)*T^C(i,5)));end % initial guess of Pdew using PD_VLE_ID(C,T,y)[PD,xDew]=PDew_Raoult(C,Ps,Z,T); %initial guess of PD(1) and calculation of x1[gamma,~]=ACTIVITY_WILSON(MW,rhoL,BIP,T,Z);% calculation of gamma at the initial guess of x1iter=0;while  max(abs((PD*Z-Ps.*Z.*gamma)./(PD*Z)))>0.001 &&iter<1000  %isofugacity conditions and control on the  number of iterations    PD=1/sum(Z./Ps.*gamma);    xDew=(PD*Z)./(Ps.*gamma);    [gamma,~]=ACTIVITY_WILSON(MW,rhoL,BIP,T,Z);% initial guess of gamma    iter =iter +1;endif iter<1000    PD=1/sum(Z./Ps.*gamma);    xDew=(PD*Z)./(Ps.*gamma);else    PD=0;    xDew=0;    disp("bubble point not found");endend%%function[PD,xDew]=PDew_Raoult(C,Ps,y,T)% compute dew pressure at defined T for a mixture with a user given vapour% pressure using the Raoult Lawc=length(y);for i=1:c    Ps=exp((C(i,1))+(C(i,2)/T)+(C(i,3).*log(T))+(C(i,4).*T.^C(i,5)));PD=1/sum(y./Ps);xDew=y*PD./Ps;end%%function[PB,y]=Pbubble_Raoult(C,Ps,Z,T)%this is a function that calculates the bubble point of a fluid with given%vapour pressure and composition i=length(Z); Ps=exp((C(i,1))+(C(i,2)/T)+(C(i,3).*log(T))+(C(i,4).*T.^C(i,5)));PB=Ps.*Z;y=Ps.*Z/PB;end%%function[PB,y]=PB_VLE_Wilson(Z,C,MW,rhoL,T,BIP)% this is a function that calculates the bubble point using the wilson% activity coeefficient model.c=length(Z);for i=1:c   Ps(i)=exp(C(i,1)+C(i,2)/T+C(i,3).*log(T)+C(i,4).*(T).^(C(i,5)));    [gamma,~]=ACTIVITY_WILSON(MW,rhoL,BIP,T,Z);    PB=sum(Ps(i).*Z.*gamma);    y=Ps(i).*gamma/PB;    disp('PB VLE Wilson')    disp(PB)    disp(y)end%%function [ alphaV ] = RACHFORDRICE_BISECT( K,Z )%This function applies the bisection method to the Rachford-Rice equation%for alphaV in (0,1).%Input/output are on molar basis. a=0;b=1;%psi_0=sum(z.*(K-1))%psi_1=sum((z.*(K-1))./K)while b-a>0.000001    alphaV=(a+b)/2;    psi_alphaV=sum((Z.*(K-1))./((1-alphaV)+alphaV*K));    psi_b=sum((Z.*(K-1))./((1-b)+b*K));    if psi_alphaV*psi_b<0        a=alphaV;    else        b=alphaV;    endendend%%function[Xeq, Yeq, alphaV, Fl, Fv]=PTFLASH_VLE_Wilson(C,MW,rhoL,BIP,P,T,Z)%this is a function that calculates PT flash for non -ideal systems where K%cannot be explicit since it depends on X which is also a variablex=length(Z);for i=1:x  Ps(i)=exp(C(i,1)+C(i,2)/T+C(i,3).*log(T)+C(i,4).*(T).^(C(i,5)));end% validating the possibility of having VLE[PB,y]=PB_VLE_Wilson(Z,C,MW,rhoL,T,BIP);[PD,x]=PD_VLE_wilson (C,MW,rhoL,BIP,T,Z);% checking if there is VLEif  P<=PD           %% y here represents the mole fraction of componenets    Xeq=0;    Yeq=y;    alphaV=1;    Fl=0;    Fv=P*Z;    elseif P>=PB           %% x here represents the mole fraction of components    Xeq=x;    Yeq=0;    alphaV=0;    [gamma,a]=ACTIVITY_WILSON(MW,rhoL,BIP,T,Xeq);    Fl=Ps.*Xeq.*gamma;    Fv=0;else    Xeq=(x+y)/2 ;      % first guess on x    [gamma,a]=ACTIVITY_WILSON(MW,rhoL,BIP,T,Xeq);   %first guess on gamma    K=(Ps.*gamma)/P;  % first guess on K     Psi_0=sum(Z.*(K-1));        Psi_1=sum(Z.*(K-1)./K);        if Psi_0*Psi_1>=0    % bad initial guess    Xeq=0;    Yeq=0;    alphaV=0;    Fl=0;    Fv=0;    disp("bad initial guess")        else       %supposedly good initial guess            Fl=zeros(1,x);     % trick to enter the while cycle at the begininng            Fv=Fl+1;            iter=0;            % initialization of iteration count            while max(abs((Fv-Fl)./Fv))>0.00001 && iter<10000 && Psi_0*Psi_1<0                [ alphaV ] = RACHFORDRICE_BISECT( K,Z );     xeq=Z./((1-alphaV)+alphaV*K);            Yeq=K.*xeq;           [gamma,a]=ACTIVITY_WILSON(MW,rhoL,BIP,T,Z);   %Gamma new guess            K=(Ps.*gamma)/P;            psi_0=sum(Z.*(K-1));            psi_1=sum(Z.*(K-1)./K);            Fv=P*Yeq;             Fl=Ps.Xeq.*gamma;            iter=iter+1;            end         endendend``
%% input
T=343;
z=[0.1 0.9];
P=4000000;
MW=[60 100];
rhoL=[803 802];
BIP=[1972.2 3700.10;1972.2 3700.10];
C1=[88.134 153.23];
C2=[-8489.6 -155];
C3=[-9.0766 -19.848];
C4=[8.3303E-18 1.6426E-05];
C5=[6 2];
C = [C1' C2' C3' C4' C5'];
[Xeq, Yeq, alphaV, Fl, Fv]=PTFLASH_VLE_Wilson(C,MW,rhoL,BIP,P,T,Z)

``>> dbstop if error``