Re: Symbol function, a question

*To*: mathgroup at smc.vnet.net*Subject*: [mg90522] Re: Symbol function, a question*From*: "David Park" <djmpark at comcast.net>*Date*: Fri, 11 Jul 2008 02:06:47 -0400 (EDT)*References*: <g54om5$f1i$1@smc.vnet.net>

I'm not quite certain what your objective here is. x95 = 100; Notice what happens if you Trace the evaluation of the Symbol expression. Symbol["x" <> ToString[95]] // Trace {{{ToString[95], 95}, x<>95, x95}, Symbol[x95], x95, 100} So the statement: Symbol["x" <> ToString[95]] = 20 evaluates to: 100 = 20 which Mathematica baulks at. So if you want to reset the value of the symbol why not just write: x95 = 20 If you want x95 to change its value in other expressions when you assign a new value to it use: Dynamic[x95] Evaluate that, and then evaluate in turn: x95 = 100; x95 = 20 and see what happens to the Dynamic[x95] output. -- David Park djmpark at comcast.net http://home.comcast.net/~djmpark/ "tung tran" <tunganhtr at yahoo.fr> wrote in message news:g54om5$f1i$1 at smc.vnet.net... > Hi everybody, I have a question needing your help. > Firstly, I create a variable > x95 = 100 > Now, I want to change the value of my variable x95 to 20 , > so I want to use some procedure like : > > Symbol["x" <> ToString[95]] = 20 > my idea is to make Mathematica write the term "x95" automatically for > me but when I use the Symbol function in this case, it gives me > automatically 100 and I don' t know how to call only x95. > Thank you if someone can give me a suggestion. > > > Tung >