not enought input arguments in ode45 and isqcurvefit

Hi again! I'm still trying to solve a pharmacokinetic in 13 compartiments and fitting my concentration data vs time with the result, I've learned a lot from you all who have helped me to fix my problems with matlab. I started with solving with ode45 a system of 13 differential equations, I made it! After read Monodkinetics and Igor Moura y tryed to run an isqcurvefit with my pharmacokinetic data. I have concentration data vs time from compartiment number 12 and I want to fit them with equations system, and estimate two elimination constants (K(1) and K(2). So far I go here: I have two files First file named odefcn_script4

%
%
%       K(1)= constante de eliminación en hígado (hepatic clearance)
%       K(2)= constante de eliminación plasmática (plasmatic clearance)
t=[5
  15
  30
  60
  120
  240];
c=[11.46
  21.24
  3.35
  4.53
  1.73
  2.49];
  K0 = [1;14];
[K,Rsdnrm,Rsd,ExFlg,OptmInfo,Lmda,Jmat]=lsqcurvefit(@odefcn4,K0,t,c);
fprintf(1,'\tConstants:\n')
for k1 = 1:length(K)
  fprintf(1, '\t\tK(%d) = %8.5f\n', k1, K(k1))
end
tv = linspace(min(t), max(t));
Cfit = odefcn4(K, tv);
figure(1)
plot(t, C, 'p')
hold on
hlp = plot(tv, Cfit);
hold off
grid
xlabel('Time')
ylabel('Concentration')
legend(hlp, 'C_1(t)', 'C_2(t)', 'C_3(t)', 'C_4(t)','C_5(t)','C_6(t)','C_7(t)','C_8(t)','C_9(t)','C_10(t)','C_11(t)','C_12(t)','C_13(t)','Location','N')

and file two named odefcn4:

% File odefcn4.m
function C=odefcn4(K,t)
CLr=0.0441;
Pb=4.47176966;
Pcer=1.3191;
Pcor=3.3789;
Pf=7.2458;
Ph=6.1711;
Phu=1.2509;
Pint=3.7487;
Plu=5.4719;
Pm=2.4497;
Pp=2.53282;
Pr=6.7441;
Qb=0.0017;
Qc=0.0831;
Qcer=0.0017;
Qcor=0.0041;
Qf=0.0058;
Qh=0.0145;
Qha=0.0019;
Qhu=0.0101;
Qint=0.0109;
Qlu=0.0831;
Qm=0.0231;
Qp=0.0048;
Qr=0.0117;
Va=0.0065;
Vb=5.0000e-04;
Vcer=0.0014;
Vcor=8.0000e-04;
Vf=0.0207;
Vh=0.0092;
Vhu=0.0052;
Vint=0.0065;
Vlu=0.0012;
Vm=0.0972;
Vp=0.0429;
Vr=0.0017;
Vv=0.0129;
c0 = [0;0;0;0;0;0;0;0;0;0;0;96.8750;0];
tspan=[0,240];
[T,Cv]=ode45(@DifEq,t,c0,CLr,Pb,Pcer,Pcor,Pf,Ph,Phu,Pint,Plu,Pm,Pp,Pr,Qb,Qc,Qcer,Qcor,Qf,Qh,Qha,Qhu,Qint,Qlu,Qm,Qp,Qr,Va,Vb,Vcer,Vcor,Vf,Vh,Vhu,Vint,Vlu,Vm,Vp,Vr,Vv);
  function dC = DifEq(t,c,CLr,Pb,Pcer,Pcor,Pf,Ph,Phu,Pint,Plu,Pm,Pp,Pr,Qb,Qc,Qcer,Qcor,Qf,Qh,Qha,Qhu,Qint,Qlu,Qm,Qp,Qr,Va,Vb,Vcer,Vcor,Vf,Vh,Vhu,Vint,Vlu,Vm,Vp,Vr,Vv)
dcdt=zeros(13,1);
dcdt(1)=(Qc*((c(13)/Plu)-c(1)))/Va;
dcdt(2)=(Qf*(c(1)-(c(2)/Pf)))/Vf;
dcdt(3)=(Qp*(c(1)-(c(3)/Pp)))/Vp;
dcdt(4)=(Qhu*(c(1)-(c(4)/Phu)))/Vhu;
dcdt(5)=(Qm*(c(1)-(c(5)/Pm)))/Vm;
dcdt(6)=(Qcor*(c(1)-(c(6)/Pcor)))/Vcor;
dcdt(7)=(Qint*(c(1)-(c(7)/Pint)))/Vint;
dcdt(8)=(Qb*(c(1)-(c(8)/Pb)))/Vb;
dcdt(9)=((Qha*c(1))+(Qb*(c(8)/Pb))+(Qint*(c(7)/Pint))-(Qh*(c(9)/Ph))-(K(1)*Vh*Ph))/Vh;
dcdt(10)=((Qr*(c(1)-(c(10)/Pr)))-(CLr*c(10)))/Vr;
dcdt(11)=(Qcer*(c(1)-(c(11)/Pcer)))/Vcer;
dcdt(12)=((Qf*(c(2)/Pf))+(Qp*(c(3)/Pp))+(Qhu*(c(4)/Phu))+(Qm*(c(5)/Pm))+(Qcor*(c(6)/Pcor))+(Qr*(c(10)/Pr))+(Qcer*(c(11)/Pcer))+(Qh*(c(9)/Ph))-(Qc*c(12))-((K(2)*c(12))/Vv))/Vv;
dcdt(13)=(Qlu*(c(12)-(c(13)/Plu)))/Vlu;
dC=dcdt;
  end
C=Cv(:,12);
end

I run the first file and i got this error message:

Not enough input arguments.
Error in odefcn4/DifEq (line 58)
dcdt(12)=((Qf*(c(2)/Pf))+(Qp*(c(3)/Pp))+(Qhu*(c(4)/Phu))+(Qm*(c(5)/Pm))+(Qcor*(c(6)/Pcor))+(Qr*(c(10)/Pr))+(Qcer*(c(11)/Pcer))+(Qh*(c(9)/Ph))-(Qc*c(12)))/Vv;
Error in odearguments (line 90)
f0 = feval(ode,t0,y0,args{:});   % ODE15I sets args{1} to yp0.
Error in ode45 (line 115)
  odearguments(FcnHandlesUsed, solver_name, ode, tspan, y0, options, varargin);
Error in odefcn4 (line 44)
[T,Cv]=ode45(@DifEq,t,c0,CLr,Pb,Pcer,Pcor,Pf,Ph,Phu,Pint,Plu,Pm,Pp,Pr,Qb,Qc,Qcer,Qcor,Qf,Qh,Qha,Qhu,Qint,Qlu,Qm,Qp,Qr,Va,Vb,Vcer,Vcor,Vf,Vh,Vhu,Vint,Vlu,Vm,Vp,Vr,Vv);
Error in lsqcurvefit (line 202)
          initVals.F = feval(funfcn_x_xdata{3},xCurrent,XDATA,varargin{:});
Error in odefcn_script4 (line 19)
[K,Rsdnrm,Rsd,ExFlg,OptmInfo,Lmda,Jmat]=lsqcurvefit(@odefcn4,K0,t,c);
Caused by:
  Failure in initial objective function evaluation. LSQCURVEFIT cannot continue.
Not enough input arguments.
Error in odefcn4/DifEq (line 58)
dcdt(12)=((Qf*(c(2)/Pf))+(Qp*(c(3)/Pp))+(Qhu*(c(4)/Phu))+(Qm*(c(5)/Pm))+(Qcor*(c(6)/Pcor))+(Qr*(c(10)/Pr))+(Qcer*(c(11)/Pcer))+(Qh*(c(9)/Ph))-(Qc*c(12))-((K(2)*c(12))/Vv))/Vv;
Error in odearguments (line 90)
f0 = feval(ode,t0,y0,args{:});   % ODE15I sets args{1} to yp0.
Error in ode45 (line 115)
  odearguments(FcnHandlesUsed, solver_name, ode, tspan, y0, options, varargin);
Error in odefcn4 (line 44)
[T,Cv]=ode45(@DifEq,t,c0,CLr,Pb,Pcer,Pcor,Pf,Ph,Phu,Pint,Plu,Pm,Pp,Pr,Qb,Qc,Qcer,Qcor,Qf,Qh,Qha,Qhu,Qint,Qlu,Qm,Qp,Qr,Va,Vb,Vcer,Vcor,Vf,Vh,Vhu,Vint,Vlu,Vm,Vp,Vr,Vv);
Error in lsqcurvefit (line 202)
          initVals.F = feval(funfcn_x_xdata{3},xCurrent,XDATA,varargin{:});
Caused by:
  Failure in initial objective function evaluation. LSQCURVEFIT cannot continue.

any help would be valuable,

Answer 1

[Walter Roberson]

The call

[T,Cv]=ode45(@DifEq,t,c0,CLr,Pb,Pcer,Pcor,Pf,Ph,Phu,Pint,Plu,Pm,Pp,Pr,Qb,Qc,Qcer,Qcor,Qf,Qh,Qha,Qhu,Qint,Qlu,Qm,Qp,Qr,Va,Vb,Vcer,Vcor,Vf,Vh,Vhu,Vint,Vlu,Vm,Vp,Vr,Vv);

is wrong. That call takes t as the timespan, and c0 as the initial conditions, and CLr as the options, and the items from Pb onwards as additional arguments. The options (CLr) are not passed to the function called, so where you have

    function dC = DifEq(t,c,CLr,Pb,Pcer,Pcor,Pf,Ph,Phu,Pint,Plu,Pm,Pp,Pr,Qb,Qc,Qcer,Qcor,Qf,Qh,Qha,Qhu,Qint,Qlu,Qm,Qp,Qr,Va,Vb,Vcer,Vcor,Vf,Vh,Vhu,Vint,Vlu,Vm,Vp,Vr,Vv)

then CLr of DifEq will receive the value from the caller's Pb, and Pb of DifEQ will receive the value from the caller's Pcer, and so on, with Vr of DifEq receiving the value of the caller's Vv, and with Vv of DifEq receiving no argument.

You should avoid that coding style. The ability of ode45 to receive extra arguments has been undocumented since about R6.5 over a decade ago.

http://www.mathworks.com/help/matlab/math/parameterizing-functions.html

[María Elena Bravo-Gómez]

thank you very much!. It was very helpful!