precision for floating number fails after 15th decimal

[kenn]

I noticed that gawk floating number calculator function (mpfr_atan2) prints wrong numbers after 15th decimal.

The following gawk command prints pi:

`awk 'BEGIN { x = 1; y = 1; result = 4*atan2 (y,x); printf " %.20f degrees\n", result}'`

`3.14159265358979311600 degrees`

But it must be `3.14159265358979323846`

[kenn (whatnext)]

It's not a bug, precision value must be set in the follwing way:
awk -M -v PREC=10000 'BEGIN { x = 1; y = 1; result = 4*atan2 (y,x); printf " %.50f\n", result}'