POV-Ray : Newsgroups : povray.newusers : Calculation errors : Calculation errors Server Time 9 Dec 2023 10:07:07 EST (-0500)
 Calculation errors
 From: kurtz le pirate Date: 14 Sep 2023 11:23:06 Message: <6503255a\$1@news.povray.org>
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Hello,

I'm trying to adapt an Excel spreadsheet in POV. I've got a strange problem.

In Excel
Cell E19 = 280.8191102;
Cell E20 = 23.43825611;
Cell E21 = DEGRES ( ATAN2 ( COS(RADIANS(E19));

E21 = -78.23396726

In POV
#declare E19 = 280.8191102;
#declare E20 = 23.43825611;

RESULT = 168.233967

No obvious relationship between this -78.2 and +168.2
How to explain this difference ?

Especially since the correct value is -78.2 or 281.7 !
(Note that the numbers after the decimal point are exactly the same.)

Are the origins of angles and rotation direction in Excel and POV
different ?

help apprecied

--
Kurtz le pirate
Compagnie de la Banquise
```