[ncl-talk] Plotting average station values on map

[Bassill, Nicholas]

Hi Emma,
    I think you're trying to do something similar to what I try to do in real-time - maps like: <http://operations.nysmesonet.org/~nbassill/climate/index.php?climate=daily> http://operations.nysmesonet.org/~nbassill/climate/index.php?climate=weekly

Skipping to just the relevant parts of that code, it's something like (where delim = ","):


sitefile  = "weekly.dat"

sitedata  = asciiread(sitefile,-1,"string")

sitelats  = tofloat(str_get_field(sitedata,1,delim))

sitelons  = tofloat(str_get_field(sitedata,2,delim))

siteanom  = tofloat(str_get_field(sitedata,3,delim))

size = dimsizes(sitelons)


<other stuff - maybe put your map stuff here>


;;;;;;;;;;;; this part tells the marker what color to be based on the anomaly

markercolors = new(size(0),"integer")

do n=0,size(0)-1,1

  markercolors(n) = round((siteanom(n)*10),3)+127

end do

markercolors=where((markercolors.lt.17),17,markercolors)

markercolors=where((markercolors.gt.255),237,markercolors)


stationmarker = new(size(0),graphic)

do n=0,size(0)-1,1

mres                = True         ; marker resources for best track

mres at gsMarkerIndex  = 16           ; marker style (filled circle)

mres at gsMarkerSizeF  = 23.0          ; marker size

mres at gsMarkerColor  = markercolors(n)      ; marker color

mres at tfPolyDrawOrder= "PostDraw"


stationmarker(n) = gsn_add_polymarker(wks,plot,sitelons(n),sitelats(n),mres)


tres                      = True                ; text mods desired

tres at tfPolyDrawOrder  = "PostDraw"

tres at txFont = "helvetica-bold"

tres at txFontHeightF        = 0.014

    if any(siteanom.lt.-9.5)

      tres at txFontHeightF        = 0.011

    end if

stationtext  =     gsn_add_text(wks,plot,round(siteanom(n),3),sitelons(n),sitelats(n),tres)

end do


<other stuff, like colorbar, text, etc.>


draw(plot)



This loops through and plots a color-coded dot, then adds the raw value on top of it later. Here, there's some trial and error involved when I calculate the markercolor for each station - it's an arbitrary (value*10 + 127), which fits in well with the color scheme, but it could just as easily be anything else.



Nick Bassill, PhD

Modeler & Meteorologist, New York State Mesonet

LC SB-28, 1400 Washington Ave.,

SUNY, University at Albany, NY 12222

(518) 442-6375

http://nysmesonet.org/


________________________________
From: ncl-talk <ncl-talk-bounces at ucar.edu> on behalf of Emma Nelson <enelson23 at wisc.edu>
Sent: Tuesday, November 28, 2017 1:07 PM
To: ncl-talk at ucar.edu
Subject: [ncl-talk] Plotting average station values on map


Hi,


I have monthly averages of ozone data and am trying to figure out how to plot them with different colors given a certain range.  The only examples I can find are using dummy data, and I'm having trouble figuring out how to apply this to actual data.


My averages are:

average1 = 37.62

average2 = 39.49

average3 = 36.36

I want to display these values as different colors.  For example, I want one color for values less than 37, one between 37 and 39, and one greater than 39.  Here is what I've tried:



arr = (/0.,37.,39./)

do i = 0, num_distinct_markers-1


if (i.eq.0) then

indexes = ind(average3.lt.arr(37))

labels(i) = "x < " + arr(37)

end if


if (i.eq.num_distinct_markers-1) then

indexes = ind(average2.gt.arr(39))

labels(i) = "x > " + arr(39)

end if


if (i.gt.arr(37).and.i.lt.arr(39)) then

indexes = ind(average1.gt.arr(37).and.average1.lt.arr(39))

labels(i) = arr(37) + "< x < " + arr(39)

end if

end do


I'm pretty sure most of this is wrong, but I don't know what a lot of the functions mean, so any help would be appreciated!


Thanks,

Emma Nelson
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