Re: How to display the desired numerical precision?
- To: mathgroup at smc.vnet.net
- Subject: [mg25241] Re: How to display the desired numerical precision?
- From: "Allan Hayes" <hay at haystack.demon.co.uk>
- Date: Sun, 17 Sep 2000 04:47:19 -0400 (EDT)
- References: <8psg4f$a2m@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Christopher, A number's precision and how it is displayed are independently controlable. Display can be controlled using NumberForm or PaddedForm. Here is one way. myForm[x_, n_:6] := NumberForm[SetPrecision[x, n], ExponentStep -> Infinity ] We need to turn off a message: Off[NumberForm::"sigz"] myForm[A[1234567.9, Pi, E, -1.2 ], 4] A["1235000.", "3.142", "2.718", "-1.200"] myForm[A[1234567.9, Pi, E, -1.2 ]] A["1234570.", "3.14159", "2.71828", "-1.20000"] Turn the message back on. On[NumberForm::"sigz"] If we leave out the NumberForm we get numbers instead of strings but we also get SetPrecision[1234567.9, 4] 6 1.235 10 Allan --------------------- Allan Hayes Mathematica Training and Consulting Leicester UK www.haystack.demon.co.uk hay at haystack.demon.co.uk Voice: +44 (0)116 271 4198 Fax: +44 (0)870 164 0565 "Christopher R. Carlen" <crcarle at sandia.gov> wrote in message news:8psg4f$a2m at smc.vnet.net... > Hi: > > In Mathematica 3, I could input > > N[ Pi, 12 ] > > and see 12 digits of result. However in Mathematica 4 I see 6 digits, no matter > what I put in for the number of digits, unless >16. In other words, > > N[ Pi, 17 ] > > shows 17 digits. > > It seems that for less than or equal to machine precision, the result > gets displayed using the setting of Formatting Options|Expression > Formatting|Display OPtions|Print Precision. > > But for numbers greater than the maching precision, the result displays > according the precision specified to the N function. > > Can someone tell me how to get the following behavior from Mathematica 4: > > If I don't specify anything about precision, show 6 digits. > > Else if I specify any number of digits to N[] from 1 to n, then display > n digits. > > Thanks for input. > -- > _______________________ > Christopher R. Carlen > Sr. Laser/Optical Tech. > Sandia National Labs >