New firmware for the Swissmicros DM15L

[Johnp_g]

Hi again

I was pondering the "small results that should be zero" problem - and the "erroneous imaginary part" in a Y^X for negative number to an integer power.

My thought was "do we need more than 11 digits of precision?

What would happen if answers were rounded to say 11 digits after being calculated with whatever the number of digits is (16? 17?)?

As an example

fFIX 14
180
SIN (1.2246467991E-16)
fFIX 11 (1.2246467991e-16)
gRND

Now we have 0.00000000000

or

fFIX 14
3
CHS
ENTER
3
y^x ( -27.0000 + i9.92E-15)
fFIX 11
gRND

now we have -27.00000000000

This seems a reasonable compromise, to limit the displayed precision to 11 digits.

A new BUG became apparent while I was checking this idea.......

I notice though that the FIX and RND function do some strange things.

fFIX 14
g PI

3.14159265358979

gRND

3.14159265353419

We're rounding to the number of digits set by FIX - i.e. 14 - but the last 4 digits of PI change after using gRND

fFIX 9

3.141592654

gRND

3.141592654

now expand digits to fFIX 14

3.14159265400000

this is correct.

Odd things happen when gRND is used on numbers with FIX greater than 9

when FIX is 10 and gRND is used the final displayed digit changes, when FIX is 13 and gRND is used the final 3 digits change.

Nothing should happen except the number being rounded to the number of digits specified in FIX, then if FIX is expanded to a greater number of digits we should see the new digits are zero.

This happens if FIX is 9 when gRND is used, but not if it's greater than 9.

I'm confusing myself now, so I'll just leave it here and see if you or Jean-Charles have any comments.

John