KevinSee / STADEM

Estimate escapment across a dam
https://kevinsee.github.io/STADEM/
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Vignette Figure 4.1 Caption #21

Open mackerman44 opened 1 year ago

mackerman44 commented 1 year ago

The caption in Figure 4.1 has a potential error. It states "Panel A shows the posterior estimate of fish crossing while the window is open... That estimate is then divided by the nighttime passage rate"

However, it seems that the estimate of fish crossing while the window is open should be multiplied by 1 + the nighttime passage rate. E.g., if we estimate that 500 fish pass while the window is open and the nighttime passage rate is 0.10 (50 fish), then the number of fish passing the window would be 500 x (1 + 0.1) = 550.

I initially thought is was simply a typo intended to be "divided by the daytime passage rate", but that doesn't seem to be correct e.g., 500 / 0.9 = 556.

KevinSee commented 11 months ago

I think it should be changed to "divided by the daytime passage rate" or "divided by 1 - nighttime passage rate". If 500 fish total pass the dam, and nighttime passage is 0.1, then we'd expect to count 500 * 0.1 = 450 fish while the window is open. If you take that window count and divide by the daytime passage rate (1 - 0.1), then you get 450 / 0.9 = 500.

That figure starts with the counts while the window is open, 450 in the example above.