From a7de0cf27620ba36d8b0fa422297ca33c86adb9a Mon Sep 17 00:00:00 2001 From: Levi Harrison Date: Mon, 27 Sep 2021 07:00:08 -0400 Subject: [PATCH] Remove example and experimental Signed-off-by: Levi Harrison --- docs/querying/operators.md | 32 +------------------------------- 1 file changed, 1 insertion(+), 31 deletions(-) diff --git a/docs/querying/operators.md b/docs/querying/operators.md index a34574c50..ae6265f6e 100644 --- a/docs/querying/operators.md +++ b/docs/querying/operators.md @@ -44,37 +44,7 @@ the result. The following trigonometric binary operators, which work in radians, exist in Prometheus: -* `atan2` (based on https://pkg.go.dev/math#Atan2, _This is experimental_) - - A usecase of `atan2` is converting directional data between the [polar](https://en.wikipedia.org/wiki/Polar_coordinate_system) (r, theta) - and [cartesian](https://en.wikipedia.org/wiki/Cartesian_coordinate_system) (x, y) coordinate forms. - - Example: - - Take some wind speed and direction data in the polar form. To get a trend over a - longer period of time, it's not correct to just average out the direction data. - The polar data needs to be converted into the cartesian form: - - ``` - wind:northwards = windspeed * cos(rad(winddirection)) - wind:westwards = windspeed * sin(rad(winddirection)) - ``` - - Having done that, the longerterm averages over northwards and westwards now make sense: - - ``` - wind:northwards:avg1h = avg_over_time(wind:northwards[1h]) - wind:westwards:avg1h = avg_over_time(wind:westwards[1h]) - ``` - - The "average" direction can be extracted out of these again by using `atan2`: - - ``` - wind:direction:avg1h = deg(wind:northwards:avg1h atan2 wind:westwards:avg1h) - ``` - - The Wikipedia article on the circular mean has more about this calculation: - https://en.wikipedia.org/wiki/Circular_mean +* `atan2` (based on https://pkg.go.dev/math#Atan2) Trigonometric operators allow trigonometric functions to be executed on two vectors using vector matching, which isn't available with normal functions. They act in the same manner