[ncl-talk] 2ND TIME POST: add polyline with gsn_csm_pres_hgt_vector

[Dennis Shea]

" I am not sure how to add a polyline using the right y-axis"

I did not write this so I am guessing:

I think the right-y-axis ("Height") is not a y-coordinate. Rather,
'under-the-hood,' a function (say) Height = f(pressure) was used to
estimate the heights for labeling purposes.

if the x-axis is (say, lat or lon), and you have:
      polyline_values = f(x,height)
then you may have to recast the 2nd line in terms of pressure and add
like the 1st polyline





On Wed, Aug 19, 2015 at 2:16 PM, Zhifeng Yang <yangzf01 at gmail.com> wrote:
> Hi
>
> Sorry for posting this problem again. Since I haven't received reply from my
> previous post, I promote it by myself.
>
> I want to add a polyline on a image generated by gsn_csm_pres_hgt_vector,
> and the y value of the polyline is height, which is the right y-axis. I can
> add a polyline using the left y-axis, but I need to reverse pressure to plot
> a polyline. I don't know how to plot a polyline with reversed y-axis. Most
> important, I am not sure how to add a polyline using the right y-axis. Do
> you know how to fix it?
> Thank you.
>
> Best,
> Zhifeng
>
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