Sollya User's Manual

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roundcorrectly rounds an approximation range correctly to some precision

sollya_obj_t sollya_lib_roundcorrectly(sollya_obj_t)

roundcorrectly(range) : range -> constant

Let range be a range of values, determined by some approximation process, safely bounding an unknown value v. The command roundcorrectly(range) determines a precision such that for this precision, rounding to the nearest any value in range yields to the same result, i.e. to the correct rounding of v.

If no such precision exists, a warning is displayed and roundcorrectly evaluates to NaN.

   > printbinary(roundcorrectly([1.010001_2; 1.0101_2]));
   1.01_2
   > printbinary(roundcorrectly([1.00001_2; 1.001_2]));
   1_2

> roundcorrectly([-1; 1]);
@NaN@