Re: How to call 'Clear' from within a function?
- To: mathgroup at smc.vnet.net
- Subject: [mg124917] Re: How to call 'Clear' from within a function?
- From: James Stein <mathgroup at stein.org>
- Date: Sun, 12 Feb 2012 05:01:41 -0500 (EST)
- Delivered-to: l-mathgroup@mail-archive0.wolfram.com
- References: <201202091038.FAA18317@smc.vnet.net> <201202111139.GAA16453@smc.vnet.net>
I thank all the responders for helping me to clarify my thoughts on this issue.
The reason I was using Strings, not Symbols, is too complicated and
too uninteresting to detail here.
To answer Albert Retey's question, what I was trying to do: I was
planning to investigate how precision affected certain computations.
It was my intention to set (and reset) various variables by calling a
single function which would repeatedly call a function such as this
one:
ClearAll [ f, x, watt, meter ];
SetAttributes [ f, HoldFirst ];
f [ var_, expr_, precision_, units_: 1 ] := (
ClearAll [ var ];
var = If [ precision == 0, expr,
SetPrecision [ expr, precision ] ] units );
(* examine f: *)
f [ x, 5., 0 ]
f [ x, 5., 8 ]
f [ x, 5., 12, watt meter ^ -2 ]
As usual, an urge to increase precision turned moot with a more clever
algorithm.
- References:
- How to call 'Clear' from within a function?
- From: James Stein <mathgroup@stein.org>
- Re: How to call 'Clear' from within a function?
- From: Bob Hanlon <hanlonr357@gmail.com>
- How to call 'Clear' from within a function?