Solving coupled pdes with different type of sources

I am trying to solve a system of three equations, two of which I can represent with constants and one is a function of the state of u. I tried following the example on page 2-66 of the pde toolbox manuel. In my function I have f(1,:)=ones(1,length(location.x)), F(2,:) the same as f(1,:) and f(3,::)=state.ux+state.uy. I get the following error

Error using pde.CoefficientAssignment/checkCoefFcnHdlArgCounts (line 505)

Function specifying a coefficient must accept two

input arguments and return one output argument.

Error in pde.CoefficientAssignment/checkFcnHdlArgCounts (line 272)

self.checkCoefFcnHdlArgCounts(self.f, systemsize, ndims);

Error in pde.CoefficientAssignment (line 104)

obj.checkFcnHdlArgCounts(systemsize, numdims);

Error in pde.PDEModel/specifyCoefficients (line 143)

coef = pde.CoefficientAssignment(self.EquationCoefficients,argsToPass{:});

Error in pde4EarthScript (line 77)

specifyCoefficients(model,'m',0,'d',0,'c',cc,'a',af1,'f',@fcoeff,'face',3);