Timeline for Enter exact rational numbers easily with decimal notation
Current License: CC BY-SA 3.0
8 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Dec 31, 2018 at 22:36 | comment | added | theorist | @Ruslan I encountered a case in which your suggested addition causes george2079's code to break where it otherwise would have been fine: When there is a trailing decimal point (e.g., 100./3). One might encounter these if you've deliberately added trailing decimals to numericize evaluations within a notebook, and then use george's code to conveniently reevaluate the notebook using exact numbers. | |
| Feb 26, 2018 at 7:57 | comment | added | Ruslan | @theorist not quite: insert it before the trailing semicolon — to make the pattern conditional | |
| Feb 26, 2018 at 7:43 | comment | added | theorist |
@Ruslan: By "append to the end of fract" do you mean exactly this?: fract[s_String] := (ToExpression[StringReplace[s, "." -> ""]]/ 10^(StringLength[s] - First@First@StringPosition[s, "."]));/; StringMatchQ[s, RegularExpression["[+-]?[0-9]*\\.[0-9]+"]]
|
|
| Apr 9, 2017 at 9:06 | comment | added | Ruslan |
May be a good idea to append /; StringMatchQ[s, RegularExpression["[+-]?[0-9]*\\.[0-9]+"]] to your fract: this will avoid all the possible breakage with unexpected formats of the string, returning unevaluated expression instead.
|
|
| Mar 14, 2017 at 18:11 | history | edited | george2079 | CC BY-SA 3.0 |
deleted 23 characters in body
|
| Apr 15, 2014 at 16:57 | comment | added | george2079 |
The point is to work with the actual text entered to avoid some of the issues raised in the comments arising from conversion to/from machine precision. (As a practical matter those issues may not be important, and using $Pre like that is clearly cleaner and more robust )
|
|
| Apr 15, 2014 at 16:06 | comment | added | Simon Woods |
How about $Pre = # /. r_Real :> RuleCondition[Round[r, 10^-Ceiling@Precision@r]] &
|
|
| Apr 15, 2014 at 15:30 | history | answered | george2079 | CC BY-SA 3.0 |