Problem with simulator
- Thread starter BESQUEUT
- Start date
Simulator is supposed to be used for debuging purpose... so this may append...
By the way, are problems with ATAN, SIN and COS fixed ?
Last edited:
http://www.picaxe.com/Software/PICAXE/PICAXE-Editor-6/#tRevisionHistory
Note that each command is only valid within certain values - for instance ATAN is only ever valid between 0-100 (0-1 when not multiplied by 100)
See here for sin and cos value info, which were already correct - http://www.picaxe.com/BASIC-Commands/Variables/let/
Note that each command is only valid within certain values - for instance ATAN is only ever valid between 0-100 (0-1 when not multiplied by 100)
See here for sin and cos value info, which were already correct - http://www.picaxe.com/BASIC-Commands/Variables/let/
In simulation, SIN and COS are not conform to documentation for angle>90°
Please have a look to last posts
This example works ok for us in simulation. Can you be more precise in where you believe the error is?
Code:
[COLOR=Blue]for [/COLOR][COLOR=Purple]w0 [/COLOR][COLOR=DarkCyan]= 0 [/COLOR][COLOR=Blue]to [/COLOR][COLOR=Navy]360
[/COLOR][COLOR=Purple]b2 [/COLOR][COLOR=DarkCyan]= sin [/COLOR][COLOR=Purple]w0
[/COLOR][COLOR=Blue]if [/COLOR][COLOR=Purple]b2 [/COLOR][COLOR=DarkCyan]>= [/COLOR][COLOR=Navy]128 [/COLOR][COLOR=Blue]then
[/COLOR][COLOR=Purple]b2 [/COLOR][COLOR=DarkCyan]= [/COLOR][COLOR=Purple]b2 [/COLOR][COLOR=DarkCyan]- [/COLOR][COLOR=Navy]128
[/COLOR][COLOR=Blue]sertxd ([/COLOR][COLOR=Black]#[/COLOR][COLOR=Purple]w0[/COLOR][COLOR=Black], [/COLOR][COLOR=Red]" -"[/COLOR][COLOR=Black],#[/COLOR][COLOR=Purple]b2[/COLOR][COLOR=Black],[/COLOR][COLOR=Blue]cr[/COLOR][COLOR=Black],[/COLOR][COLOR=Blue]lf)
else
sertxd ([/COLOR][COLOR=Black]#[/COLOR][COLOR=Purple]w0[/COLOR][COLOR=Black], [/COLOR][COLOR=Red]" +"[/COLOR][COLOR=Black],#[/COLOR][COLOR=Purple]b2[/COLOR][COLOR=Black],[/COLOR][COLOR=Blue]cr[/COLOR][COLOR=Black],[/COLOR][COLOR=Blue]lf)
end if
next [/COLOR][COLOR=Purple]w0[/COLOR]
You are right, and I did not read correctly the documentation :
Note that the 128 is used as a sign indicator and the resulting value is not a two's complement representation.
I understood that it was two's complement... witch is coherent with Picaxes perfectly working with two's complement negatives numbers,
at least for add, substract and multiply.
Maybe a day, we will define a symbol directly as being negative...
symbol toto=-4
Hi,
For example 255 * 255 (-1 * -1) produces a result of 65025 (-511) not +1 .
Cheers, Alan.
PICaxe does not work "perfectly" (or at all) multiplying negative numbers.
For example 255 * 255 (-1 * -1) produces a result of 65025 (-511) not +1 .
Cheers, Alan.
Ohhhh ! Did not saw that ! Was only trying for -1 *2 or 2*-1
Many thanks : that may be a big problem cause.
I have to verify my code... one operator must be positive for each multiply.
Till usable for add, substract and multiply by a positive integer, that is more than nothing and very usefull for trigo.
(I did rewrote SIN, COS, ASIN, ACOS and ATAN2 to be usable with two-s complement numbers...)
Used to compensate a magnetometer.
I am on the way to write a new library to implement floating point numbers.
It is more correct to say that unsigned maths can, in appropriate circumstances, deliver a result as expected when two's complement values are used. In some cases the results will not be as expected. This is particularly so when mixing byte and word variables.