Re: Approximate Zero Times A Symbol

*To*: mathgroup at smc.vnet.net*Subject*: [mg127122] Re: Approximate Zero Times A Symbol*From*: Richard Fateman <fateman at eecs.berkeley.edu>*Date*: Sun, 1 Jul 2012 02:09:54 -0400 (EDT)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com*References*: <201206270811.EAA18698@smc.vnet.net> <19783652.3140.1340794328091.JavaMail.root@m06> <jsh3a9$sir$1@smc.vnet.net> <18402214.58885.1341077225203.JavaMail.root@m06> <000501cd56f2$cb6cec40$6246c4c0$@comcast.net>

I don't know much about NumberFormat or Sliders, but look at this: Coefficient[a*x+b*y, {x,y}] returns {a,b} Coefficient[ b*y,{ x,y}] returns {0,b} I get the feeling that there is something resembling a "thought crime" that is causing you problems. That is, confusing the "computation of a value" and the "display of some attributes of a value". It is not necessary to change the Accuracy or Precision of a value to display it. It is not necessary for you to make Mathematica to (not) simplify 0.0*x to 0.0. All you have to do is figure out what you want to display, as above. NumberForm is essentially a way of taking values and computing some strings of characters. The string for a number has some relation with the actual value, but given a result of {0,b} from Coefficient, presumably you can make any kind of string you wish, e.g. x-coefficient y-coefficient ---------------------------------------- |.........0........|..........b........| ---------------------------------------- RJF On 6/30/2012 12:01 PM, djmpark wrote: > Thanks for your reply Richard. > > Basically I was interested in formatting a vector a x + b y to so many > places and keeping both terms present even when a or b was an approximate > zero. (My dislike of Dynamic displays that jitter and jump.) ..big snip...