atan #207
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jordens
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Dec 17, 2020
jordens
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Dec 17, 2020
dsp/src/trig.rs
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| /// The angle between the x-axis and the ray to the point (x,y). The | ||
| /// result range is from i32::MIN to i32::MAX, where i32::MIN | ||
| /// corresponds to an angle of -pi and i32::MAX corresponds to an | ||
| /// angle of +pi. |
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Is that really correct? i32::MAX != -i32::MIN.
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I think it's actually i32::MIN == -pi and at the same time also i32::MIN == pi. Then i32::MAX == pi*(1 - 1/(1 << 31))
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Oh, right that makes sense. It's also worth noting that i32::MIN is not actually reachable. I can get i32::MAX with atan2(0, i32::MIN). The closest results are 2147461318 and -2147461318 with atan2(1 << 16, i32::MIN)) and atan2(-1 << 16, i32::MIN)).
jordens
reviewed
Dec 17, 2020
dsp/src/trig.rs
Outdated
| /// The angle between the x-axis and the ray to the point (x,y). The | ||
| /// result range is from i32::MIN to i32::MAX, where i32::MIN | ||
| /// corresponds to an angle of -pi and i32::MAX corresponds to an | ||
| /// angle of +pi. |
There was a problem hiding this comment.
I think it's actually i32::MIN == -pi and at the same time also i32::MIN == pi. Then i32::MAX == pi*(1 - 1/(1 << 31))
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Bors r+ |
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207: atan r=jordens a=matthuszagh Adds 2-argument arctangent function. Parameters and result are `i32` integers for fast computation. Only the 16 MSBs of the inputs are used (16 LSBs are discarded). The x and y inputs can range from -1 to 1, which corresponds to `i32::MIN` and `i32::MAX`, respectively. The output ranges from -pi to pi, which corresponds to `i32::MIN` and `i32::MAX`, respectively. - [godbolt](https://rust.godbolt.org/z/nahKrT) # Related - #206 Co-authored-by: Matt Huszagh <huszaghmatt@gmail.com>
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Canceled. |
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Bors r+ |
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Adds 2-argument arctangent function. Parameters and result are
i32integers for fast computation. Only the 16 MSBs of the inputs are used (16 LSBs are discarded). The x and y inputs can range from -1 to 1, which corresponds toi32::MINandi32::MAX, respectively. The output ranges from -pi to pi, which corresponds toi32::MINandi32::MAX, respectively.Related