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Charts - Wind charts: Difference between revisions
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== Introduction == | == Introduction == | ||
The Wind charts submodule consists of two charts: | The Wind charts submodule consists of two charts: | ||
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The chart is configured with the following parameters (explained in [[Charts#WindRoseNrOfWindforceClasses_.26_WindRoseMaxWindSpeed|the chapter Charts]]): | The chart is configured with the following parameters (explained in [[Charts#WindRoseNrOfWindforceClasses_.26_WindRoseMaxWindSpeed|the chapter Charts]]): | ||
[Graphs] | |||
WindRoseNrOfWindforceClasses=6 (default = 6) | WindRoseNrOfWindforceClasses=6 (default = 6) | ||
WindRoseMaxWindSpeed=60 (default = 60) | WindRoseMaxWindSpeed=60 (default = 60) | ||
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[[Category:CumulusUtils]] | [[Category:CumulusUtils]] | ||
The configuration of the charts and YADR report is actually straight forward but the user needs to be aware of this configuration especially when having configured CumulusMX to use imperial units and/or the station is residing in a region with dominantly very high or very low winds. | |||
=== Windrose configuration === | |||
#As stated above the number of Windrose sections is taken from the CumulusMX inifile parameter ''NumWindRosePoints'' and you need to adjust the compass direction texts as indicated above | |||
#Then the user has to to reflect that the Windrose is not very good in displaying very small percentages. As a hurricane will be very rare you should define your windspeed above which you group all windspeeds in only one class. So be aware that maybe a hurricane wind is interesting but the Windrose won't be able to show it if it occurs only once in ten years for two hours. So if your normal windspeeds go up to 50 km/hr (or let's say 30 mi/hr) you set ''WindRoseMaxWindSpeed=50 (or 30 when mi/hr)'' in the unit you use. This number is not converted in any way and is simply a limit for the data as it is in your logs. | |||
#Then the user needs to define how many classes need to be in the Windrose. As above, too small classes won't sufficiently show some windspeeds, too large slasses won't hold enough information. Experiment with ''WindRoseNrOfWindforceClasses'' to get it right. | |||
The defaults for the parameters for the Windrose are good for ''km/hr'' but anybody using deviating units should reflect on these parameter values. | |||
=== Windrun configuration === | |||
The Windrun is a bit more automated but still the user has to define the class width through the parameter ''WindrunClassWidth'' (which has a default of 75). Again the default is OK for a ''distance unit of km'', reconsider if using imperial. '''Note that if you use a speed unit of m/s, the distance of the Windrun will be in km'''. | |||
With the ''WindrunClassWidth'' the following is calculated: | |||
#The maximum windrun which ever occurred on the station is determined (call it ''MaxWindRun'') | |||
#The <math>number of windrun classes</math> is calculated as: <math>\left (\frac{MaxWindRun}{WindrunClassWidth}\ + 1 \right)</math> | |||
#Then all classes are defined as (Loop over the number of windrun classes as calculated above) <math>class[ i ] = WindrunClassWidth + i \times WindrunClassWidth</math> | |||
These classes are used for the Windrun chart. | |||
=== YADR Report class configuration === | |||
A similar procedure is used for the legend under the YADR Windrun report with the difference that here always 13 classes are used. Reason is that the extreme classes are easier to see in this colour accented text report than it is in the percental Windrun chart. | |||
