Just ran into this tonight and it makes me somewhat nervous. I've stripped it down to the bare essentials. Try it out yourself and see what you think:
0.21-0.01
With wxMaxima 15.08.2 under Windows XP, this is evaluated as 0.2.
With wxMaxima 15.08.2 under Linux Mint 17.2, this is evaluated as 0.19999999999999.
Rationals have two representations, and each of these versions of wxMaxima picks the other! But more serious is that fpprintprec does not properly round this latter result, but instead truncates it. So,
fpprintprec:4;0.21-0.01;
prints out: 0.19, not 0.2
Unless I'm missing something obvious in how to set things up!
Studs Kreitzer
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Hi everyone,
Just ran into this tonight and it makes me somewhat nervous. I've stripped it down to the bare essentials. Try it out yourself and see what you think:
With wxMaxima 15.08.2 under Windows XP, this is evaluated as 0.2.
With wxMaxima 15.08.2 under Linux Mint 17.2, this is evaluated as 0.19999999999999.
Rationals have two representations, and each of these versions of wxMaxima picks the other! But more serious is that fpprintprec does not properly round this latter result, but instead truncates it. So,
prints out: 0.19, not 0.2
Unless I'm missing something obvious in how to set things up!
Studs Kreitzer