What do these errors mean in matlab(ode45) ?

[ninas]

what means those errors?

hi, can somme one explane me what means these errors in matlab(ode45)

Error in ==> D:\matlab\toolbox\matlab\funfun\private\odearguments.m
On line 104 ==> f0 = feval(ode,t0,y0,args{:});

Error in ==> D:\matlab\toolbox\matlab\funfun\ode23.m
On line 154 ==> [neq, tspan, ntspan, next, t0, tfinal, tdir, y0, f0, args, ...

Error in ==> D:\matlab\work\inch.m
On line 81 ==> [t y]=ode23('pend3', tspan, y0);

??? Undefined function or variable 'n1'.

Error in ==> D:\matlab\work\pend3.m
On line 3 ==> xdot(2)=(n1-n2)/den+n3*u/den;

Error in ==> D:\matlab\toolbox\matlab\funfun\private\odearguments.m
On line 104 ==> f0 = feval(ode,t0,y0,args{:});

Error in ==> D:\matlab\toolbox\matlab\funfun\ode23.m
On line 154 ==> [neq, tspan, ntspan, next, t0, tfinal, tdir, y0, f0, args, ...

Error in ==> D:\matlab\work\inch.m
On line 81 ==> [t y]=ode23('pend3', tspan, y0);