Re: Simple List question. HELP.

*To*: mathgroup at smc.vnet.net*Subject*: [mg39404] Re: [mg39389] Simple List question. HELP.*From*: Jan Mangaldan <hokenjan at yahoo.com>*Date*: Fri, 14 Feb 2003 03:18:36 -0500 (EST)*Sender*: owner-wri-mathgroup at wolfram.com

This works: In[1]:= lst = {}; In[2]:= AppendTo[lst, {0, 1}] Out[2]:= {{0, 1}} In[3]:= AppendTo[lst, {1, 2}] Out[3]:= {{0, 1}, {1, 2}} In[4]:= AppendTo[lst. {2, c}] Out[4]:= {{0,1}, {1, 2}, {2, c}} You can find out more about AppendTo[] in The Mathematica Book. Jan M. (^_^) P.S. You can repeat the procedure as many times as necessary to keep adding elements to your list. Of course, it would be better if you just type-in the whole list. Daniel Heneghan <dhenegha at bway.net> wrote: I am new to Mathematica. This is vexing. All I want to do is create a 2-dimensional list so that I can enter x,y values and then plot the list. I want to do this programmatically. I am having such incredible trouble trying to accomplish this simple task. I know that there is probably a Mathematica optimized way to do this, but I and trying to write a little program and for now I want to stay with paradigms that I am familiar with. Here is what I have been doing. Create a 2 dimensional list. In[532] lst={{}} Out[532]= {{}} Enter the first pair into the first place in the list. In[533]:= lst[1]={{0,1}} Errors and beeps here, but it does seem to record the correct values. Set::write: Tag List in {{}}[1] is Protected. Out[533]={{0,1}} Add anoter pair of values. In[534]:= lst=Append[lst,{{1,2}}] Out[534]= {{},{{1,2}}} The second pair is OK, but the first pair has been obliterated. Add another pair. Now all subsequent entries are OK, but I still have lost the first pair. In[535]:= lst=Append[lst,{{2,c}}] Out[535]= {{},{{1,2}},{{2,c}}}-- What is going on? What are the mysteries of working with lists in Mathematica. In any programming language this is simple. I can't grasp it in Mathematica. The reason I need to do this is that for the list plot I need the x values to start at 0 not 1. Thanks, Daniel Heneghan Ceara Systems (212) 696-9208 ceara at bway.net