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Topic: unser-interface problems using Mathematica as a calculator
Replies: 2   Last Post: Nov 12, 2013 12:05 AM

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 Bob Hanlon Posts: 906 Registered: 10/29/11
Re: unser-interface problems using Mathematica as a calculator
Posted: Nov 12, 2013 12:05 AM

If you want to see the "true" value rather than a rounded display value
then set preferences to display full machine precision (Mathematica |
Preferences ... | Appearance | Numbers | Formatting | Displayed precision |
Number of digits displayed in output) or use FullForm, InputForm,
Rationalize, or exact numbers.

Note the use of parentheses with either FullForm or InputForm to avoid
including the wrapper in the definion of tv.

(tv = TimeValue[1, 0.04, 3]) // FullForm

1.124864`

(tv = TimeValue[1, 0.04, 3]) // InputForm

1.124864

tv = TimeValue[1, 0.04, 3] // Rationalize

17576/15625

tv = TimeValue[1, 4/100, 3]

17576/15625

Bob Hanlon

On Mon, Nov 11, 2013 at 12:05 AM, Alan <alan.isaac@gmail.com> wrote:

> The example below illustrates why Mathematica's display rules for
> approximate numbers are very confusing for students. Should this be
> considered a user-interface bug? If not, why not? In any case, can the
> default display be changed to something more familiar from spreadsheets and
> other computing languages?
> Thanks,
> Alan Isaac
>
> In[217]:= tv = TimeValue[1, 0.04, 3]
> tv == 1.124864
> tv == 1.12486
>
> Out[217]= 1.12486
>
> Out[218]= True
>
> Out[219]= False
>
>

Date Subject Author
11/12/13 Bob Hanlon
11/12/13 Murray Eisenberg