Odd VE table behavior

[Naf]

You know i have seen changes in my VVE as well.

I will make my changes,
click on Generate Coe...
it will all hold steady, then when i click on the save/save as the table changes in the slightest way...

[joecar]

You know i have seen changes in my VVE as well.

I will make my changes,
click on Generate Coe...
it will all hold steady, then when i click on the save/save as the table changes in the slightest way...

Can you post some screenshots before/after saving.

[Taz]

Think of it as a "rounding" adjustment (as it is not really an error). With the VVE tables, you are using a 4 digit whole number to reverse generate numerous coefficients.

You will see a similar effect with T43 (6L80) shift times, if you use more than 3 decimal places - there will be a very slight change when reopening the tune.

[joecar]

That is called bit-representation-error...

each bit position in a binary fixed point point number represents a fractional power of two, i.e. (1/2)^n where n is bit position.


For example, how would 0.6 be represented in simple fixed point binary...
0.500 = 0.100
0.250 = 0.010
0.125 = 0.001
you combine those to get other values:
0.750 = 0.110
0.875 = 0.111
but you can't represent 0.6 exactly, the closest to 3 or 4 bits is 0.101 = 0.625 or 0.1001 = 0.5625
if you go to more bits (binary decimal places), you get closer, but never exact; and the word has some fixed number of bits (say 8 or 16 or 32 or 64).


why-cant-decimal-numbers-be-represented-exactly-in-binary

[Naf]

Here are my screen shots, i did it twice to show there are also changes to my VVE after i save...