[wxqc] Text to Degrees

Sun Apr 8 23:18:18 CDT 2007

I guess I should have provided a little more information.  Here is a portion
of the data I'm getting from our weather station.

Date		Time	Direction
06/22/2006	00:00	E	
06/22/2006	00:15	ESE	
06/22/2006	00:30	ENE	
06/22/2006	00:45	SW	
06/22/2006	01:00	S	
06/22/2006	01:15	SSE	
06/22/2006	01:30	SW	
06/22/2006	01:45	S	
06/22/2006	02:00	S	
06/22/2006	02:15	SSE	
06/22/2006	02:30	S	
06/22/2006	02:45	S	
06/22/2006	03:00	SSE	
06/22/2006	03:15	S	
06/22/2006	03:30	S	
06/22/2006	03:45	SSE	
06/22/2006	04:00	SSW	
06/22/2006	04:15	SSE	
06/22/2006	04:30	SE	
06/22/2006	04:45	S	
06/22/2006	05:00	S	
06/22/2006	05:15	S	
06/22/2006	05:30	S	

I guess this discussion has raised another issue that I will have to address
(which is, how are the quarter hour directions determined?  But I'm going to
push forward on my original question right now).  So, I've used a macro to
change the text to degrees using the format I mentioned

N     0
NNE   23
NE    45
ENE   68
E     90
ESE   113
SE    135
SSE   158
S     180
SSW   203
SW    225
WSW   248
W     270
WNW   293
NW    315
NNW   338

and created this

Date		Time	Direction
06/22/2006	00:00	90
06/22/2006	00:15	113
06/22/2006	00:30	68
06/22/2006	00:45	225
06/22/2006	01:00	180
06/22/2006	01:15	158
06/22/2006	01:30	225
06/22/2006	01:45	180
06/22/2006	02:00	180
06/22/2006	02:15	158
06/22/2006	02:30	180
06/22/2006	02:45	180
06/22/2006	03:00	158
06/22/2006	03:15	180
06/22/2006	03:30	180
06/22/2006	03:45	158
06/22/2006	04:00	203
06/22/2006	04:15	158
06/22/2006	04:30	135
06/22/2006	04:45	180
06/22/2006	05:00	180
06/22/2006	05:15	180
06/22/2006	05:30	180

I have this data going back to 2000 in Excel spreadsheets and I'm interested
in determining the predominant wind direction for each month and each year
at our site.  I'm not necessarily interested in a running predominant
direction, just historical information.  

I initially just averaged the data per month and per year.  Out of
curiosity, for N, I substituted 360 for 0 and got completely different (not
surprisingly now that I think about it) monthly and yearly "average wind
directions."  This told me I was not doing something right but I thought
there must be a way that historical predominant wind direction is
determined.  Assuming that each year's spreadsheet has about 35000 rows of
readings, I'm hoping to not have to do a lot of actual manipulation of the
data.  I could always sort the data by "text" wind direction without
converting it, then sort it by date and count how many rows per month and
per year there is for each direction but I was hoping there would be a less
labor-intensive way.  I'm particularly interested in a macro if anyone has
one or any suggestions.

Thanks,
Norm

Norm Shea 
Director, Lakes Management
Kiawah Island Community Association Inc
20 Kestrel Court, Kiawah Island, SC 29455
Phone 843-768-2315 x 255  Fax 843-768-0298  Mobile 843-708-3608
Norm.Shea at kiawah-owners.org --- www.kiawah-owners.org

-----Original Message-----
From: wxqc-bounces at lists.gladstonefamily.net
[mailto:wxqc-bounces at lists.gladstonefamily.net] On Behalf Of Keith Miller
Sent: Sunday, 08 Apr 2007 22:13
To: 'Discussion of weather data quality issues'
Subject: Re: [wxqc] Text to Degrees

> -----Original Message-----
> From: wxqc-bounces at lists.gladstonefamily.net
[mailto:wxqc-bounces at lists.gladstonefamily.net]On Behalf Of Steve Hatchett
> Sent: Sunday, April 08, 2007 9:52 PM
> To: 'Discussion of weather data quality issues'
> Subject: Re: [wxqc] Text to Degrees
>
>
> For converting degrees to text, I like the following:
> http://www.tnetweather.com/nb-0002.php
>
> which is basically a two line function $windlabel = array ("N","NNE", 
> "NE", "ENE", "E", "ESE", "SE", "SSE",
"S",
>    "SSW","SW", "WSW", "W", "WNN", "NW", "NNW"); $dir = $windlabel[ 
> fmod((($winddir + 11) / 22.5),16) ];
>

Gee, that looks more complicated than mine:

function Deg2Card($degrees)
{
  $cardinal = array('N','NNE', 'NE',
'ENE','E','ESE','SE','SSE','S','SSW','SW','WSW','W','WNW','NW','NNW','
N');

  return $cardinal[round(($degrees / 22.5), 0)]; }

Keith
--
CW5250 => http://weather.stadhaugh.com

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