Re: ncl-talk Digest, Vol 119, Issue 19

From: David Brown <dbrown_at_nyahnyahspammersnyahnyah>
Date: Tue Oct 15 2013 - 14:31:32 MDT

Well, yes you are over-taxing us, because this is not a question about the use of NCL or even software in general, and we are not a math
discussion group. Nevertheless, I will attempt to answer this one time.

The speed of a rotating object is often treated in terms of revolutions per minute. The RPM of the inside and outside of your disc is exactly the same.
However the distance traveled for a point on your disc depends on the radius (distance to the center) of that point. A point on the inside has a smaller
radius than a point on the outside. For each revolution the point travels 2 * PI * radius. (PI is about 3.14). So the problem is perfectly solvable.

On Oct 16, 2013, at 9:54 AM, tiffani <> wrote:

> On 10/15/2013 11:00 AM, wrote:
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>> Today's Topics:
>> 1. Re: plot contourr lines with different colors (Adam Phillips)
>> 2. Re: plot contourr lines with different colors (Erika Folova)
>> 3. Re: plot contourr lines with different colors (Adam Phillips)
>> ----------------------------------------------------------------------
>> Message: 1
>> Date: Tue, 15 Oct 2013 11:08:35 -0600
>> From: Adam Phillips <>
>> Subject: Re: plot contourr lines with different colors
>> To: Erika Folova <>, NCL-talk <>
>> Message-ID: <>
>> Content-Type: text/plain; charset="iso-8859-1"
>> Hi Erika,
>> Yes, you need to set cnMonoLineColor = "False" and set cnLineColors. See
>> the cnLineColors description here:
>> here's a brief example:
>> wks = gsn_open_wks("x11","test")
>> gsn_define_colormap(wks,"Cat12")
>> res = True
>> ....
>> res@cnLevelSelectionMode = "ExplicitLevels"
>> res@cnLevels = (/1,2,3,4/)
>> res@cnMonoLineColor = False
>> res@cnLineColors = (/2,4,8,11/)
>> plot = gsn_csm_xy(wks,arr&time,arr,res)
>> Hope that helps. If not, please respond to the ncl-talk email list..
>> Adam
>> On 10/15/2013 11:03 AM, Erika Folova wrote:
>>> Hallo,
>>> I just wonder is it possible to draw the contour lines (as attached)
>>> with different color options
>>> in NCL? Thank you for your response.
>>> Erika
>>> _______________________________________________
>>> ncl-talk mailing list
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> Hi all,
> I am still waiting for some one to answer the problem of the spinning
> disk, did I over tax you?
> Here is how some one else has worded the same problem:
> You have a compact disc rotating at a constant speed. The outer-most
> edge of the compact disc is rotating at, say, 20 km/h. Thus, the
> inner-most edge of a compact disc is also rotating at 20km/h. It is
> easily noticeable that the outer edge is traveling a longer distance
> than the inner edge, but if this is true, then the speeds should be
> different (the outer edge should spin faster, as it has to cover more
> distance in the same period of time). But saying that the outer edge
> spins at a higher rate is also wrong. I tried this out with a paper disc
> and made two markings (one on the inner edge and one on the outer edge)
> on a straight line, and after spinning the disc for a while, the
> markings were still in line with each other. If one of the edges had
> spun faster than the other, the paper would have been ripped to pieces!
> This simple experiment proves that the outer edge spins no faster than
> the inner edge. This question seems unsolvable to me. I know that there
> must be a mathematical explanation, but what?
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Received on Tue Oct 15 14:31:42 2013

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