On 5/9/2013 7:21 AM, Nasser M. Abbasi wrote: > On 5/9/2013 2:19 AM, ghasem wrote: >> >> >> obviously,I get this error: >> ??? Undefined function or variable 'bet'. >> because I don't define bet in gam,T,tau expressions. >> how define "bet" as a numeric unknown (I don't want use from "syms >> bet")? >> > > You can't. > > Matlab is not C nor C++ nor Pascal. > > In Matlab, you can only define and assign a value at > same time, as in > > x=5; > > You can't just write > > x; > or > > var x; > > Unless it is a sym, then you can define it as symbol > with no value. > > But for numeric, it must be defined and given a value > at same time. > > --Nasser
If you are trying to write a function of bet, you could write
function [X1,X2,X3] = mycalc(bet) gam = sqrt(bet^^2 - k1^^2); ...
Alan Weiss MATLAB mathematical toolbox documentation