MATLAB: Flag command !!

flag..error

Dear All I am using flag command in my code. But when I run it this error occurs

“??? Maximum recursion limit of 500 reached. Use set(0,'RecursionLimit',N) to change the limit. Be aware that exceeding your available stack space can crash MATLAB and/or your computer” Any Help please Regards

Best Answer

You are never changing flag, so you are recursing indefinitely.

Perhaps you meant to toggle the flag:

else if (flag ==1) 
    HenXoma(~flag, etc...

Or indeed:

    HenXoma(0, etc...

Related Solutions

MATLAB: Global Flag

I'd say that Yw is not used, or has no effect, in the internal code of HenXoma (which we can't see because you didn't post it.) Why don't you post it.

If Yw is a global variable (I assume that's what "Glabal" means to you), you don't need to pass it via the argument list, you just declare it global inside the function.

MATLAB: Can’t figure out how to finalize the code

%V1=volume of first reactor in L
%V2=volume of second reactor in L
%V3=volume of third reactor in L
%V4=volume of forth reactor in L
 
%k1=first order reaction rate in units of (L^3)(M^-1)(T^-1)
%k2=second order reaction rate in units of (L^3)(M^-1)(T^-1)
%Each reactor has different reaction rate
 
%M=mass in units of M
%Qin=inflow in units of (L^3)(T^-1)
%Qout=outflow in units of (L^3)(T^-1)
%Qxy=the flow from reactor x to reactor y (x&y can be 1,2,3..)
%UNITS
%The unit for V1, V2, V3 & V4 is L
%The unit for k1 is hr^-1
%The unit for k2 is L/(mg*hr)
%The unit for M is mg
%The unit for Qin, Qout,Q12, Q23, Q34, Q32, Q43 & Qxy is L/hr
%Given and calculated values  
Qin=10;
Q12=10;
Q23=10+5; %Q23=Q12+Q32
Q34=15-5+3; %Q34=Q23-Q32+Q43
Qout=10;
Q32=5;
Q43=3;
 
Cain=1;
Cbin=0;
 
V1=25;
V2=75;
V3=100;
V4=25;
 
k11=0.05;
k12=0.1;
k13=0.5;
k14=0.1;
 
k21=0.04;
k22=0.08;
k23=0.4;
k24=0.08;
 
%% PARTA
 
%Mass Balance Eqns for Chemical Species A
 
%For reactor 1

%(Qin*Cain)-(Q12*Ca1)-(k11*Cain*V1)==0  %for first order reaction
%(Qin*Cain)-(Q12*Ca1)-(k21*(Cain)^2*V1)==0  %for second oreder reaction
 
%For reactor 2

%(Q12*Ca1)+(Q32*Ca3)-(Q23*Ca2)-(k12*Ca2*V2)==0 %for first order reaction
%(Q12*Ca1)+(Q32*Ca3)-(Q23*Ca2)-(k22*(Ca2)^2*(V2))==0 %for second oreder reaction
 
%For reactor 3

%(Q23*Ca2)+(Q43*Ca4)-(Q32*Ca3)-(Q34*Ca3)-(k13*Ca3*V3)==0  %for first order reaction
%(Q23*Ca2)+(Q43*Ca4)-(Q32*Ca3)-(Q34*Ca3)-(k23*(Ca3)^2*(V3))==0  %for second order reaction
 
%For reactor 4

%(Q34*Ca3)-(Q43*Ca4)-(Qout*Ca4)-(k14*Ca4*V4)==0  %for first order reaction
%(Q34*Ca,3)-(Q43*Ca,4)-(Qout*Ca,4)-(k24*(Ca4)^2*V4)==0  %for second order reaction
 
%Mass Balance Eqns for Chemical Species B
 
%For reactor 1
%(Qin*Cbin)-(Q12*Cb1)+(k11*Ca1*V1)==0  %for first order reaction
%(Qin*Cbin)-(Q12*Cb1)+(k21*(Ca1)^2*V1)==0  %for second oreder reaction
 
%For reactor 2
%(Q12*Cb1)+(Q32*Cb3)-(Q23*Cb2)+(k12*Ca2*V2)==0 %for first order reaction
%(Q12*Cb1)+(Q32*Cb3)-(Q23*Cb2)+(k22*(Ca2)^2*(V2))==0 %for second oreder reaction
 
%For reactor 3
%(Q23*Cb2)+(Q43*Cb4)-(Q32*Cb3)-(Q34*Cb3)+(k13*Ca3*V3)==0  %for first order reaction
%(Q23*Cb2)+(Q43*Cb4)-(Q32*Cb3)-(Q34*Cb3)+(k23*(Ca3)^2*(V3))==0  %for second order reaction
 
%For reactor 4
%(Q34*Cb3)-(Q43*Cb4)-(Qout*Cb4)+(k14*Ca4*V4)==0  %for first order reaction
%(Q34*Cb3)-(Q43*Cb4)-(Qout*Cb4)+(k24*(Ca4)^2*V4)==0  %for second order reaction
 
syms Ca1 Ca2 Ca3 Ca4 Cb1 Cb2 Cb3 Cb4
Eqns_1st_Order=[(Qin*Cain)-(Q12*Ca1)-(k11*Cain*V1)%=0















(Q12*Ca1)+(Q32*Ca3)-(Q23*Ca2)-(k12*Ca2*V2)%=0
(Q23*Ca2)+(Q43*Ca4)-(Q32*Ca3)-(Q34*Ca3)-(k13*Ca3*V3)%=0
(Q34*Ca3)-(Q43*Ca4)-(Qout*Ca4)-(k14*Ca4*V4)%=0
(Qin*Cbin)-(Q12*Cb1)+(k11*Cain*V1)%=0
(Q12*Cb1)+(Q32*Cb3)-(Q23*Cb2)+(k12*Ca2*V2)%=0
(Q23*Cb2)+(Q43*Cb4)-(Q32*Cb3)-(Q34*Cb3)+(k13*Ca3*V3)%=0
(Q34*Cb3)-(Q43*Cb4)-(Qout*Cb4)+(k14*Ca4*V4)]%=0
Eqns_1st_Order = 
 
Eqns_2nd_Order=[(Qin*Cain)-(Q12*Ca1)-(k21*(Cain)^2*V1)%=0
(Q12*Ca1)+(Q32*Ca3)-(Q23*Ca2)-(k22*(Ca2)^2*(V2))%=0
(Q23*Ca2)+(Q43*Ca4)-(Q32*Ca3)-(Q34*Ca3)-(k23*(Ca3)^2*(V3))%=0
(Q34*Ca3)-(Q43*Ca4)-(Qout*Ca4)-(k24*(Ca4)^2*V4)%=0
(Qin*Cbin)-(Q12*Cb1)+(k21*(Cain)^2*V1)%=0
(Q12*Cb1)+(Q32*Cb3)-(Q23*Cb2)+(k22*(Ca2)^2*(V2))%=0
(Q23*Cb2)+(Q43*Cb4)-(Q32*Cb3)-(Q34*Cb3)+(k23*(Ca3)^2*(V3))%=0
(Q34*Cb3)-(Q43*Cb4)-(Qout*Cb4)+(k24*(Ca4)^2*V4)]%=0
Eqns_2nd_Order = 
sol = solve(Eqns_2nd_Order, [Ca1 Ca2 Ca3 Ca4 Cb1 Cb2 Cb3 Cb4])
sol = struct with fields:
    Ca1: [8×1 sym]
    Ca2: [8×1 sym]
    Ca3: [8×1 sym]
    Ca4: [8×1 sym]
    Cb1: [8×1 sym]
    Cb2: [8×1 sym]
    Cb3: [8×1 sym]
    Cb4: [8×1 sym]
sol.Ca1
ans = 
sol.Ca2
ans = 
vpa(sol.Ca2, 3)
ans =

Best Answer

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MATLAB: Global Flag

MATLAB: Can’t figure out how to finalize the code

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