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Inverse sin/cos/tan
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| chawki@surpac.com 2006-05-24, 10:04 pm |
| Hello.
Please excuse what must be a silly question. :)
I have values that represent sin & cos of an angle. I need to compute
the angle itself. How do I use the 'expr' command to calculate inverse
sin?
Thanks,
CJ
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| suchenwi 2006-05-24, 10:04 pm |
| % expr asin(sin(1.2345))
1.2345
% expr acos(cos(1.2345))
1.2345
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| neil mckay 2006-05-24, 10:04 pm |
| If you have values for both sin AND cos, you can use atan2:
% set s [expr {sin(1.2345)}]
0.943983323945
% set c [expr {cos(1.2345)}]
0.329993157679
% expr {atan2($s,$c)}
1.2345
This will guarantee that the angle's in the right quadrant.
Neil
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