[ncl-talk] calculating and plotting change in standard deviation and change of both skewness and kutosis at 99% percentile
Dennis Shea
shea at ucar.edu
Tue Nov 5 18:21:11 MST 2019
The attached calculates the ensemble (N=100) mean wave height, standard
deviation, skewness and kurtosis at each time step.
Then it plots ensembl mean time series.
This should get you started.
On Wed, Oct 30, 2019 at 10:08 AM Dennis Shea <shea at ucar.edu> wrote:
> Possibly:
> (a) For each time period
> (b) For each statistic,
> (c) For each location or for all locations [45*90] sort into ascending
> order and pick the highest 1%
> --------
> If you can make the file available, I can take a look.
>
> Dropbox or ftp
>
> ftp ftp.cgd.ucar.edu
> anonymous
> your_email
> cd incoming
> put zo_hist_1850-2005_ens_1-100.nc
> quit
>
> After successful file transfer, send me an email.
>
> On Wed, Oct 30, 2019 at 9:16 AM Sri.durgesh Nandini-Weiss via ncl-talk <
> ncl-talk at ucar.edu> wrote:
>
>> Hello everyone,
>>
>> I'm attempting to calculating, and plot changes for extreme value from
>> sea surface height from an ensemble outputs.
>>
>> For e.g i am trying to analyse the change between 1986-2006 and 2081-2100
>> at the 99% percentiles from the ensemble from the change in statistics
>> (mean, standard deviation and change of both skewness and kutosis). I
>> adapted my script from extval_6.ncl
>>
>> Is the below the correct way?
>>
>> ;************************************************
>> ; extvalv_6.ncl
>> ;
>> ; Concepts illustrated:
>> ; - Using extval_mlegev and extval_gev
>> ; - Calculate basic statistics
>> ; - Basic statistics of the original sample
>> ; - Estimate GEV distribution parameters
>> ; - Creating a 'text' object to attach to a plot
>> ;************************************************
>>
>> fn = "zo_hist_1850-2005_ens_1-100.nc" ; define filename [time |
>> 1872] x [ens | 100] x [depth | 1] x [lat | 45] x [lon | 90]
>>
>> in = addfile(fn,"r") ; open netcdf
>> file
>> ts = in->zo ; read in
>> variable
>> printVarSummary(ts)
>>
>> ;************************************************
>> ; calculate deviation from zonal mean
>> ;************************************************
>> anom = dim_rmvmean_n_Wrap(ts,0)
>> printVarSummary(anom)
>>
>> ;***************************************************************
>> ;--- "Normal" (conventional) statistical estimates for full sample
>> ;***************************************************************
>>
>> xStat4 = dim_stat4_n(ts, 0) ; 1st 4 moments of original sample
>> printVarSummary(xStat4 )
>>
>> xAvg = xStat4(0) ; original sample mean
>> xStd = sqrt(xStat4(1)) ; " sample std dev
>> xSkew = xStat4(2) ; skewness; departure from symmetry
>> xKurt = xStat4(3) ; kurtosis; relative to a normal
>> distribution
>> xLow = min(ts)
>> xMed = dim_median_n(ts,0) ; median of original sample
>> xHi = max(ts)
>>
>>
>> ;***************************************************************
>> ;--- PLOTS
>> ;***************************************************************
>>
>> wks = gsn_open_wks ("pdf","ext6") ; send graphics to
>> PNG file
>>
>> gsn_define_colormap(wks,"default")
>> plot = new(2, "graphic")
>>
>> ;************************************************
>> ; Panel
>> ;************************************************
>>
>> resP = True ; modify the panel
>> plot
>> resP at gsnMaximize = True ; ps, eps, pdf
>> resP at gsnPanelMainString = "River Flow Rate" ; use this for NCL
>> V6.4.0 and later
>> resP at txFontHeightF = 0.020
>> gsn_panel(wks,plot,(/1,2/), resP) ; now draw as one plot
>>
>> ;***************************************************************
>> ;--- create histogram for the original sample
>> ;***************************************************************
>>
>> resh = True
>> resh at gsnDraw = False
>> resh at gsnFrame = False
>> resh2gsnHistogramNumberOfBins = 11
>>
>> resh at gsFillColor = "green"
>> resh at tiMainString = "SSH: N="+ntim
>> plt_hist = gsn_histogram(wks, ts ,resh)
>>
>> ;***************************************************************
>> ;--- text object original sample statistics; place on histogram
>> ;***************************************************************
>>
>> txres = True
>> txres at txFont = "helvetica-bold"
>> txres at txFontHeightF = 0.0150
>> textSample = (/" Mean="+sprintf("%5.1f", xAvg) +"~C~"+ \
>> " Std="+sprintf("%5.1f", xStd) +"~C~"+ \
>> " Skew="+sprintf("%5.2f", xSkew) +"~C~"+ \
>> " Kurt="+sprintf("%5.2f", xKurt) +"~C~"+ \
>> " xLow="+sprintf("%5.1f", xLow) +"~C~"+ \
>> " xMed="+sprintf("%5.1f", xMed) +"~C~"+ \
>> " xHi="+sprintf("%5.1f", xHi ) /)
>> txBoxSample = gsn_create_text(wks,textSample, txres)
>>
>> amres = True
>> amres at amParallelPosF = 0.30 ; move legend to the right
>> amres at amOrthogonalPosF = -0.10 ; move the legend up
>> annoSample = gsn_add_annotation(plt_hist, txBoxSample, amres) ;
>> Attach string to plot
>>
>> draw(plt_hist)
>> frame(wks)
>>
>>
>>
>> the change in statistics--
>> Sri Nandini-Weiß
>> Research Scientist
>>
>> Universität Hamburg
>> Center for Earth System Research and Sustainability (CEN)
>> Cluster of Excellence 'Climate, Climatic Change, and Society' (CLICCS)
>>
>> Bundesstrasse 53, 20146 Hamburg
>> Tel: +49 (0) 40 42838 7472
>>
>> _______________________________________________
>> 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/20191105/082cb017/attachment-0001.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: Sri_Nw.stats.ncl_v0
Type: application/octet-stream
Size: 3345 bytes
Desc: not available
URL: <http://mailman.ucar.edu/pipermail/ncl-talk/attachments/20191105/082cb017/attachment-0001.obj>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: EnsWaveStat.000001.png
Type: image/png
Size: 101221 bytes
Desc: not available
URL: <http://mailman.ucar.edu/pipermail/ncl-talk/attachments/20191105/082cb017/attachment-0004.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: EnsWaveStat.000002.png
Type: image/png
Size: 113690 bytes
Desc: not available
URL: <http://mailman.ucar.edu/pipermail/ncl-talk/attachments/20191105/082cb017/attachment-0005.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: EnsWaveStat.000003.png
Type: image/png
Size: 99119 bytes
Desc: not available
URL: <http://mailman.ucar.edu/pipermail/ncl-talk/attachments/20191105/082cb017/attachment-0006.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: EnsWaveStat.000004.png
Type: image/png
Size: 89518 bytes
Desc: not available
URL: <http://mailman.ucar.edu/pipermail/ncl-talk/attachments/20191105/082cb017/attachment-0007.png>
More information about the ncl-talk
mailing list