A station model is a diagram for recording the weather at a certain place and time.
You must write the shortest code possible to graphically output a simplified (explained later) station model.
A tick is a line on the wind barb. A 50 knot tick is a triangle. A 10 knot tick is a line. A 5 knot tick is half the length of a 10 knot tick. The windspeed is indicated by summing the ticks, using the largest value symbols whenever possible. The ticks start at the end of the line and are arranged in descending order of size toward the circle. An exception is 5 knots, where the tick is placed a short distance away from the end (to avoid ambiguity with 10 knots.)
Here is some pseudocode to calculate the ticks required
set f=int(s/5) set t=int(f/2) f=f-(t*2) set ft = int(t/5) t=t-(ft*5)
Where f is the number of 5 knot ticks, t is the number of 10 knot ticks and ft is the number od 50 knot ticks. (This rounds down to the nearest 5, but your code should round up or down, whichever is nearer.) Note that there is only ever one 5 knot tick.
You may only display two things on your station model: wind speed and direction. These must be supplied by the user: hardcoding is not permitted. The wind speed must be a positive integer in knots while the wind direction must be in letters (e.g. NNE, W, ESE). 16 points of the compass will be considered (up to three letters.) See http://en.wikipedia.org/wiki/Points_of_the_compass
The 50 knots tick must be as in the picture above.
Set cloud cover to clear (the circle must be empty.) The highest wind speed allowed is 201 knots (round it to 200).
Since the wind ticks only increase in imcrements of 5, round all wind speeds to the nearest 5.
As always, since this is code golf, the shortest code wins.
All of the following have a cloud cover of clear.
20 knots, SW (225°)
15 knots, N (0°)
50 knots, NNE
12 knots S
112 knots WNW