# MATLAB: Subscript indices must either be real positive integers or logicals.

debug

I am running this code an keep hitting this error when running the code. It occurs in line 36. The suggestions said it is matrix or vector related so i have indexed and called any variable as a constant yet it still occurs.
Pc = 2.74e6; Tc = 530.3; count=0;yellow=0;T = [100:.1:1000]; Pr = [0.02, 0.50, 1.0, 2.0];P = Pc.*Pr;V = 1:length(T);acen = .333;R = 8.3145; b = 0.0778*R*Tc/Pc;Cp_IG = (1:length(T));colors = ['y' 'm' 'r' 'c'];colorindx = 1;hold on;for Puse = P    n = 1;      Cp = 1:length(T);      yellow=yellow+1;      for Tuse = T;          a =3.243943838*(1.858281421-0.3727046432e-1*sqrt(Tuse))^2 ;            Vest1 = R*Tuse/Puse;          Vest2 = R*Tuse/(Puse+(a/(Vest1*(Vest1 + b)+b*(Vest1-b))))+b;          while abs((Vest1-Vest2))/Vest1 > .0001              Vest1 = Vest2;              Vest2 = R*Tuse/(Puse+(a/(Vest1*(Vest1 + b)+b*(Vest1-b))))+b;          end          t=abs(Tuse);          V(n) = Vest2;          v=abs(Vest2)          ts=sqrt(t);          count=count+1          if v>.00014;              z= -t*(8.314/(v-0.1251897785e-3)+(.1209032931*(1.858281421-0.3727046432e-1*sqrt(t)))/((v(v+0.1251897785e-3)+0.1251897785e-3)*sqrt(t)))^2/(-8.314*t/(v-0.1251897785e-3)^2+3.243943838*(1.858281421-0.3727046432e-1*sqrt(t))^2*(v+0.1251897785e-3)/(v(v+0.1251897785e-3)+0.1251897785e-3)^2)+t*(8.314000000*ln(v-0.1251897785e-3)-(.40274*(sqrt(t)*atan(89.3763*v+0.55945e-2)-49.8594*atan(89.3763*v+0.55945e-2)))/sqrt(t))-12.253+.8642*t-0.6289e-3*t^2+1.836000000*10^(-7)*t^3;              x= 0;              c= 0;              Cp(n)=z+x+c;          else              Cp(n)=0;          end;          n = n+1;      end;      semilogy(T, Cp, colors(colorindx));      colorindx = colorindx+1;end;

z= -t * (8.314 / ( v - 0.1251897785e-3) + (.1209032931 * (1.858281421 - 0.3727046432e-1 * sqrt(t))) / ((v * (v + 0.1251897785e-3) + 0.1251897785e-3) * sqrt(t)))^2 / (-8.314 * t / (v - 0.1251897785e-3)^2 + 3.243943838 * (1.858281421 - 0.3727046432e-1 * sqrt(t))^2 * (v + 0.1251897785e-3) / (v * (v+0.1251897785e-3)+0.1251897785e-3)^2)+t*(8.314000000*log(v-0.1251897785e-3)-(.40274*(sqrt(t)*atan(89.3763*v+0.55945e-2)-49.8594* atan(89.3763*v+0.55945e-2)))/sqrt(t))-12.253+.8642*t-0.6289e-3*t^2+1.836000000*10^(-7)*t^3;