Equations Solver function in Matlab. How do I handle [eqns,vars] = getEqns(varargin{:}) errors?

Question

I am using Matlab and am using its solve function. I run this code and I keep getting this error [eqns,vars] = getEqns(varargin{:}) I realized I had some parens issues and fixed those but it still does work any ideas?

Asp = 3.90;

Arg = 12.48;

Lys = 10.54;

His = 6.04;

Glu = 7.70;

Gly = 7.50;

Val = 7.44;

Pro = 8.36;

Ser = 6.93;

Thr = 6.82;

Tyr = 10.07;

Ala = 7.59;

Met = 7.00;

Cys = 5.02;




syms pH;

solve( '55*(10.^(pH-Glu))/(1+(10.^(pH-Glu))) + 43*(1/(1+(10.^(pH-Arg))))+ 55*(10.^(pH-

Asp))/(1+(10.^(pH-Asp))) + 22*(1/(1+(10.^(pH-Lys))))+ 13*(10.^(pH-Tyr))/(1+(10.^(pH-Tyr))) 

+ 6*(1/(1+(10.^(pH-His)))) + 1*(10.^(pH-Cys))/(1+(10.^(pH-Cys)))');

Answer 1

I believe the error is due to your equation. Whether 'pH' is positive or negative, your equation can never equal zero, since all the subtraction occurs in the exponent. Have you checked the signs in the rest of the equation?