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windrose color ramp issue

5 messages · Adrienne Wootten, MacQueen, Don, Clint Bowman

Adrienne Wootten
# 
Greetings!

I'm having an issue with the windrose produced by the windrose
function from the circular package.  For our weather stations in North
Carolina I'm helping with a script which takes hourly wind speed and
direction data to create windroses for our end users.  One of the
stations in the mountains frequently reaches wind speed of 40 to 60
mph and in storms can reach wind speed over 80 mph.  This has brought
up an issue with the color ramp.

Currently the color ramp works one of two ways:

#1) Holding the pedal colors fixed:

incrspeeds = 2 # fills out the increments argument
pedalcolors =  c("darkblue","blue","royalblue","darkturquoise","forestgreen","green","yellowgreen","yellow4","yellow","orange","red","darkred","violetred","mediumorchid","purple")

#or 2) Making the pedal colors dynamic based on the increments and the
max wind speed.

incrspeeds = 2 # fills out the increments argument

breaks=seq(0,round(maxwind),incrspeeds) # maxwind is the maximum wind speed
numcolors=length(breaks)

if(numcolors>length(pedalcolors)){
pedalcolors=rev(rainbow(numcolors))
}

# In either case the result ends up in the wind rose function

rose=windrose(wr,breaks=NULL,bins=numpedals,increment=incrspeeds,main=NULL,fill.col=pedalcolors,plot.mids=FALSE,units="degrees",template="geographics",ticks=FALSE,osize=0.05,cir.ind
=0.05,cex=0.9,zero=NULL,rotation=NULL,right=FALSE,shrink=NULL,label.freq=TRUE,calm=c("0"),number.calm=TRUE)

The issue when there are really large wind speeds in the first case,
the windrose wraps the color ramp twice in both the legend and the
windrose itself, and then gives only white for the remaining bands of
each pedal.  For the second case, when pedalcolors will have the same
number of colors as numcolors, the legend has the right color ramp,
but the pedals of the windrose don't have all the colors that are
passed to it.  Say pedalcolors has 40 colors, which are included in
the legend, but the windrose only includes the first 16 colors in
pedalcolors.

Any thoughts as to why this might be happening in either case?  Thanks!

Adrienne
Adrienne Wootten
# 
An update on this particular problem I've been having.  It seems that
the number of pedals (the bins argument of the windrose command) is
somehow effecting the number of colors that will be plotted.  This
makes no sense since it only controls the number of pedals in the
windrose not the number of colors.

A
On Mon, Dec 12, 2011 at 4:20 PM, Adrienne Wootten <amwootte at ncsu.edu> wrote:

  
    

      
      
    

  


  


      

    

    

      
      

        


  

        

      Adrienne Wootten
    

    

      
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The issue is solved.  For those who wish to use windrose out of the
circular package and have more groups magnitude than they do pedals,
please note the following line in the windrose function -

fill.col = rep(fill.col,length.out=bins) # where bins is the number of
pedals, fill.col is the fill colors for the pedals

This line the function forces the number of colors in the windrose to
be equal to the number of pedals, which frankly makes no sense to me.
I have since fixed the windrose function in the circular package,
replacing the above line with the following:

if(length(fill.col)<J){
	fill.col <- rep(fill.col,length.out=J) # J is the number of groups
}

This correction forces the number of colors to be equal to the number
of groups of magnitudes, when the number of colors is smaller than the
number of groups - otherwise it functions as normal for too many
colors.

This is my correction for issues regarding the number of colors,
submitted so it will hopefully stay in an archive somewhere for the
next person who has this problem.

A

        
On Tue, Dec 13, 2011 at 12:12 PM, Adrienne Wootten <amwootte at ncsu.edu> wrote:

            

      
      
      
    

        

  
    

      
      
    

  


  


      

    

    
1 day later

    

      
      

        


  

        

      MacQueen, Don
    

    

      
      #
    

  


  

      
There is also a windrose (though not with that name) function in the
openair package.
-Don

  
    

      
      
    

  


  


      

    

    

      
      

        


  

        

      Clint Bowman
    

    

      
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library(openair)
?windRose