Re: Maintaining values of variables
- To: mathgroup@smc.vnet.net
- Subject: [mg11793] Re: Maintaining values of variables
- From: Allan Hayes <hay@haystack.demon.co.uk>
- Date: Sat, 28 Mar 1998 00:25:28 -0500
- References: <6fd5n9$6bi@smc.vnet.net>
blimbaum_jerry@ccmail.ncsc.navy.mil wrote:
>
> I notice that Mathematica maintains the value of variables from
> previous work even if the files for that work are closed. I find
> this
> positively annoying. Can someone explain the rational for this?
> Also, the In/Out numbering..Why is this seqence not unique to the
> file
> I'm working with, i.e. I would expect In=1 at the start of each
> file.
> Again, what is the rational?
>
> Thanks. Jerry Blimbaum US Navy Lab, Panama City, Florida
Jerry:
VALUES
Values are kept until the kernel is closed (by quitting Mathematica or
just the kernel) or they are cleared by using a command like Clear see
below.
In[62]:=
?Clear
"Clear[symbol1, symbol2, ... ] clears values and definitions for the
symboli. \ Clear[\"form1\", \"form2\", ... ] clears values and
definitions for all \ symbols whose names match any of the string
patterns formi."
More in the Help Browser
Examples:
In[58]:=
a=2; b=3;
In[59]:=
Clear[a,b]
In[60]:=
{a,b}
Out[60]=
{a,b}
I find the following very useful:
Clear["`*"]
clears all values for unprotected symbols in the Global context (the
usual interactive one).
IN/ OUT NUMBERS
In[] Out[] numbering works similarly
We can reset the numbering - at the risk of losing references by line
number.
In[63]:=
$Line = 0;
In[1]:=
a=2
Out[1]=
2
RATIONAL
We can work with multiple notebooks.
--
Allan Hayes
Mathematica Training and Consulting
Leicester, UK
hay@haystack.demon.co.uk
http://www.haystack.demon.co.uk
voice: +44 (0)116 271 4198
fax: +44 (0)116 271 8642