A stupid but practical question

*To*: mathgroup at smc.vnet.net*Subject*: [mg25825] A stupid but practical question*From*: Chen Jisheng <chenjs at iopp.ccnu.edu.cn>*Date*: Sat, 28 Oct 2000 01:41:17 -0400 (EDT)*Sender*: owner-wri-mathgroup at wolfram.com

Dear Sir, As a new user, I need to solve the following problem. For example, I have a complicated equation f(x,T,m)==0 of T, and x, for a range of T (e.g., T=10-200). The m is a parameter, which can be inputed with hand. For a given value of T and m, I can find a solution x of above equation with "commands". So on, with hand input the values of T in a range, I can find all the solutions for a given parameter m. With a pen at hand, I can write down all the groups of T and x with a concrete value of m. The final aim is to draw out the curve x-T with given m. Reinputing the data of groups (x,T) such as written down above, I can draw out the curve. But I think above method is not a intelligent solution. With programming, I think mathematics can sovle it more efficiently. With a given value of m, here is my question: 1) How to do the programming? Although I try it some times with the Do-loop, but the intermediate value of x can not be displayed with a group of T in one loop. 2) With the programming, I hope to control a table such as t={{x,T}}. In every loop, I find only the value of the first group (x,T) can be appended to such this table. In the loop, how can I append the new value of T and x to this table? 3) Another way, if I have a data file such as: d.dat "T x" 10 200 15 210 20 211 ... In the loop of programming, how can I open this data file, add new data and close this data file? You may think it is a stupid question although it is very practical. Although I was a student with high score in "BASIC","FORTRAN" and even "C", I still find it difficult to solve it clever because I don't know exactly how to operate the data file in the (loop) programming, of course with mathematics. Looking forward to receiving the reply. J.-S CHen, Institute of Particle Physics, Hua-Zhong Normal University, Wuhan 430079,China