[ncl-talk] Polar plots - Actual pole / Latitudes ?

[Rick Brownrigg]

Hi Helen,

To you second question:  it looks like the resource "mpGridLatSpacingF"
controls the latitude grid. The default is 15-deg, which checks out with
your plot. I don't know of a way to label lats on a polar plot, and none of
our examples show this.

As for the 1st question, I still think that perhaps your data does not
extend all the way to the pole (can you confirm?), and what we are seeing
that looks like a marker is actually blank background along with remnants
of the dashed longitude grid. If you look closely at that grid, all the
lines except the 0,90,180,270, stop at the 75th latitude line, whereas
those 4 continue on to the pole. The dashed nature of the lines makes it
look like a tick-mark. In any case, if the data does not extend all the way
to 90-deg, the plotting routines will not interpolate, and so you'll need
to find some other means to interpolate the data across the pole before
plotting.  I'm not really expert at this.

I hope that helps,
Rick

On Thu, Jan 18, 2018 at 6:38 AM, HELEN PARISH via ncl-talk <
ncl-talk at ucar.edu> wrote:

> As requested, I am attaching a plot to illustrate what the issues are. As
> you can see, it looks like the data should be present over the pole itself,
> but seems to be overlaid by some kind of pole marker.
>
> Also, I am unable to tell what the latitudes are on the plot.
>
> Thanks,
> Helen.
>
> On Tue, Jan 16, 2018 at 9:39 PM, HELEN PARISH <hparish at ucla.edu> wrote:
>
>> a couple of important questions:
>>
>> 1) How can I make a polar plot that has the data at the actual pole ?. By
>> default the plotting software seems to put a white circle with a cross
>> inside at the pole. However, it is clear from the appearance of the data
>> right next to the pole that data could easily be interpolated right over
>> the pole. Could you please tell me how to put data on the pole, rather than
>> the white circle with the cross in it ?.
>>
>> 2) What are the latitudes plotted on the polar plot be default ?. There
>> appear to be 6 dashed division lines between whatever the outermost
>> latitude is and the pole. Are these 15 degree latitude bands ?. Or are
>> these 10 degree latitude bands and it does not plot all the way from the
>> pole to the equator ?. Is there a way to label the latitudes on the polar
>> plot so you know what you are looking at ?.
>>
>> Thanks,
>> Helen.
>>
>
>
> _______________________________________________
> ncl-talk mailing list
> ncl-talk at ucar.edu
> List instructions, subscriber options, unsubscribe:
> http://mailman.ucar.edu/mailman/listinfo/ncl-talk
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.ucar.edu/pipermail/ncl-talk/attachments/20180118/64d97a8a/attachment.html>