[plt-scheme] Printing

You could do:

(define (decimal-places n places)
   (* 1.0 (/ (floor (* n (expt 10 places))) (expt 10 places))))

... or something similar. I thought there was some kind of interpolation 
library in Planet that allowed something like your first example? (I 
could be making that up, though.)

M

Evan Farrer wrote:
> This is a really simple question, but I can't find the answer anywhere (help-desk, google, etc.).  How do you control, how many decimal places get printed with a floating pointer number.
> 
> For example I want somthing like:
> 
> (define PI 3.1479)
> 
> (printf "~1.2a\n" PI) => 3.14
> 
>  or
> 
> (printf "~a\n" (decimal-places PI 2)) => 3.14
> 
> 
> Thanks,
> 
> Evan
> 
> 
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