<div dir="ltr">An alternative:<br><br>nggog can be used. Sample code segments follow. For small radii Npts=100 is fine but for large radii and nice circles, Npts=360 might be better.<br><br>;=========================================================================<br>; On a sphere with radius 6371 km, one degree is approximately 110.57 km.<br>;---<br>; Of course, the earth is an oblate spheroid:<br>; <a href="http://www.longitudestore.com/how-big-is-one-gps-degree.html">http://www.longitudestore.com/how-big-is-one-gps-degree.html</a><br>;=========================================================================<br>; <a href="https://www.ncl.ucar.edu/Document/Functions/Built-in/nggcog.shtml">https://www.ncl.ucar.edu/Document/Functions/Built-in/nggcog.shtml</a><br>;=========================================================================<br><br>;---One station<br><br> slat = 0.0 ; station lat<br> slon = 0.0 ; lon<br> srad_km = (/ 50, 100, 150, 5*110.57/)*1.0 ; station radii (km)<br> km2deg = 1/110.57 ; conversion factor: deg ==> km<br> ; one degree is approximately 110.57 km.<br> srad_dg = srad_km*km2deg ; km ==> deg; nggcog requires degrees<br><br> Nrad = dimsizes(srad_dg) ; # of radii<br> Npts = 100 ; # of points at each radii (arbitrary) <br><br> Rlat = new((/Nrad, Npts/), "float") ; lat at each radius<br> Rlon = new((/Nrad, Npts/), "float")<br><br> do nr=0,Nrad-1<br> print("nr="+nr+" srad_km="+srad_km(nr)+"; srad_dg="+srad_dg(nr))<br> print("")<br><br> nggcog(slat, slon, srad_dg(nr), Rlat(nr,:), Rlon(nr,:))<br><br> print(Rlat(nr,:)+" "+ Rlon(nr,:))<br> print("========")<br> end do<br><br>+++++++++++++++++++++++++++++++++++++++++++++++++++++<br>;---Multiple stations<br><br> slat = (/ 0.0, 50.0 /) ; station lat<br> slon = (/ 0.0, 30.0 /) ; lon<br> srad_km = (/ 50, 100, 150, 5*110.57/)*1.0 ; station radii (km)<br> km2deg = 1/110.57 ; conversion factor: deg ==> km<br> ; one degree is approximately 110.57 km.<br> srad_dg = srad_km*km2deg ; km ==> deg; nggcog requires degrees<br> Nrad = dimsizes(srad_dg) ; # of radii<br><br> Nsta = dimsizes(slat) ; # stations<br> Nrad = dimsizes(srad) ; # of radii<br> Npts = 100 ; # of points at each radii (arbitrary; eg 360) <br><br> Rlat = new((/Nsta, Nrad, Npts/), "float") ; lat at each radius<br> Rlon = new((/Nsta, Nrad, Npts/), "float")<br><br> do ns=0,Nsta-1<br> do nr=0,Nrad-1<br> nggcog(slat(ns), slon(ns), srad(nr), Rlat(ns,nr,:), Rlon((ns,nr,:))<br> end do<br> end do<br><br></div><div class="gmail_extra"><br><div class="gmail_quote">On Thu, Feb 8, 2018 at 2:38 AM, Karin Meier-Fleischer <span dir="ltr"><<a href="mailto:meier-fleischer@dkrz.de" target="_blank">meier-fleischer@dkrz.de</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div text="#000000" bgcolor="#FFFFFF">
Hi Soumik,<br>
<br>
you can use polymarkers to plot the circles around lat/lon
locations. Have a look at example newcolor_4.ncl at <a href="http://ncl.ucar.edu/Applications/Scripts/newcolor_4.ncl" target="_blank">http://ncl.ucar.edu/<wbr>Applications/Scripts/newcolor_<wbr>4.ncl</a><br>
<br>
I've attached an example script using random data for marker size
and lat/lon locations overlayed on filled contour map.<br>
<br>
Hope this helps.<br>
<br>
-Karin<br>
<br>
<div class="m_-3527953815923975900moz-cite-prefix">Am 08.02.18 um 00:55 schrieb Soumik
Basu:<br>
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<div>Hello NCL-users,<br>
<br>
</div>
I am trying to draw circles around a station with
different radius. For example 50 Km, 100 Km, 150 Km etc. <br>
<br>
So, I am wondering if there is any way to do it in NCL. <br>
<br>
I looked at the "nggcog" function but from the description
what I understand is that it can draw circles along a
great circle only not according to a given distance. <br>
<br>
</div>
Thank you for any help. <br>
<br>
</div>
Thanks,<br>
</div>
Soumik<br clear="all">
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<div><br>
-- <br>
<div class="m_-3527953815923975900gmail_signature">
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<div dir="ltr">
<div>-- </div>
“We’ve all got both light and dark inside us.
What matters is the part we choose to act on.
That’s who we really are.” – J.K. Rowling
<div><br>
</div>
<div>******************************<wbr>******************************<wbr>******************************<wbr>********</div>
<div>Dr. Soumik Basu</div>
<div>Post Doctoral Research Faculty</div>
<div><span style="font-size:12.8px">International
Arctic Research Center, UAF, Fairbanks,
AK, USA</span></div>
<div><span style="font-size:12.8px">PhD in
Atmospheric Sciences</span><br>
</div>
<div>M.Sc. in Atmospheric Sciences</div>
<div>Email: <a href="mailto:suvro05@gmail.com" target="_blank">suvro05@gmail.com</a></div>
<div>website: <a href="http://soumikbasu.weebly.com/" target="_blank">http://soumikbasu.weebly.com/</a></div>
<div><br>
</div>
<div>******************************<wbr>******************************<wbr>******************************<wbr>*********</div>
</div>
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