Steel series Direction gauge questions189
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jfels private msg quote post Address this user | |
| The Steel Series direction gauge has two needles. One for Latest and the other for Average. I am having trouble understanding how the Average section of this gauge works. What is the source of this input? It always reads 0 for me. If I add a second source, I merely get a second gauge. Is there any way to turn off the Average readout on this widget? I really don't need it anyway. On the subject of average for wind direction. There does not appear to be any appropriate rollup option for wind direction. Wind direction is a Vector value rather than a Scalar value and requires a Vector Average. For example if you use a straight numerical average of two directions 30 degrees and 330 degrees, you would get 180 degrees. The correct answer is 0 degrees. |
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MikeMills private msg quote post Address this user | |
We didn't spend much time playing with this widget as we're not that knowledgeable in the science of wind  . That being said, what you're saying makes sense.You might be the first attempting to use the average feature on this control. Anyone else have a solution? I wonder if a derived stream could do the appropriate calculation? We'll take a look at this, in a couple of days if you or anyone else doesn't have a solution. We're a bit busy to investigate it asap. |
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MikeO private msg quote post Address this user | |
| Over how many data points would you need to have the average? What is the interval of those streams (10s, 1 M, 10M, etc?). | ||
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MikeMills private msg quote post Address this user | |
| Research, so far, indicates the formula is: sa = sum of sines of angles sb = sum of cosines of angles A = ( arctan(sa/sb) ) mod 360 or A = arctan(sum( [sin(x1) + sin(x2) ...sin(xn)] ) / sum( [cos(x1) + cos(x2) ...cos(xn)] ) ) mod 360 What is the time range you'd like to report the average over? How many direction samples will exist in that time range? Derivation may be a solution if there are 15 or less samples and a rolling average is acceptable. You wouldn't be able to use the average pointer, but would have to have a second wind gauge and just title it "Average" and have it reference the derived stream. |
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