# Determine the number of days with North-East wind direction from the number of days with North and East wind direction? [closed]

I have some data like:

Wind flow from north direction = “X” Numbers of days.

Wind flow from east direction = “Y” Numbers of days.

Then is there any formula to know numbers of days wind flows from North-East direction?

## closed as unclear what you're asking by Brandon Enright, Kyle Kanos, Colin McFaul, Kyle Oman, alemiJul 16 '14 at 23:57

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• What do you call wind from North-East direction? Is it simply the days in which the wind comes both from the north and the west? Normally, wind-speed is a vector, meaning it has a magnitude, and a direction. As such, do you define the wind coming from the north, as having a direction of 180 $\deg$? This means that if the wind is coming from the north, it is coming from the north only, and thus, no east-west component is present, making north-east wind impossible. I suggest you post a sample of your data, as well as tell us something more about your method (e.g. programming or something else) – ROIMaison Jul 16 '14 at 7:07
• Is the average of the two way off? – BMS Jul 16 '14 at 15:32
• What is the actual problem you are trying to solve? Are you sure that the dataset is as you describe, or is it a set of wind components in the U (E-W) and V (N-s) direction, which is standard for weather data? – EnergyNumbers Jul 17 '14 at 10:55

• Well, there is the "pigeon-hole" theorem, ie if $X + Y$ exceeds the number of days in the observation set, you can place a lower bound on the number of North-East days. :-) – Carl Witthoft Jul 16 '14 at 11:46