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<DIV><FONT color=#000000 size=3 face=宋体>Hi Dennis,</FONT></DIV>
<DIV><FONT size=3> I am still confused on your example and do not
know how to caculate <A
href="mailto:spec@coher_probability">spec@coher_probability</A> exactly.
Can you tell me what is the coh, why you set it as 0.5 in your example? Is
it the confidence level(0.9, 0.95, 0.99) or <A
href="mailto:spec@coher">spec@coher</A>? What is the relationship between df and
jave? Is df twice of jave? </FONT></DIV>
<DIV><FONT size=3> Also, I found the formula </FONT></DIV>
<DIV><FONT size=3> B=1-p**(1/(df/2-1))
(1)</FONT></DIV>
<DIV><FONT size=3>from the reference, but your example is</FONT></DIV>
<DIV><FONT size=3>
p = 1.-(1.-coh)**(df/2.-1.) (2)</FONT></DIV>
<DIV><FONT size=3></FONT> </DIV>
<DIV><FONT size=3> why are they different? Is the p in (2) same as p or B
in (1) ? Which one is the <A
href="mailto:spec@coher_probability">spec@coher_probability</A> from the
function </FONT><FONT size=2>specxy_anal<FONT size=3> in
NCL?</FONT></FONT></DIV>
<DIV><FONT size=3></FONT> </DIV>
<DIV><FONT size=3> Thanks.</FONT></DIV>
<DIV> </DIV>
<DIV align=left><FONT color=#c0c0c0 size=2 face=Verdana>2013-09-19</FONT></DIV>
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<DIV><FONT face="Times New Roman">Xueming Zhu 朱学明<BR>Key Laboratory of Research
on Marine Hazards Forecasting (LoMF), SOA<BR>National Marine Environmental
Forecasting Center (NMEFC)<BR>No.8, Dahuisi Road, Haidian District, Beijing,
100081<BR>People's Republic of
China<BR>Tel:+86-10-82481923</FONT></DIV></DIV></DIV></STATIONERY></DIV></STATIONERY></SPAN></FONT></DIV>
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</FONT></DIV>
<DIV><FONT size=2 face=Verdana><STRONG>发件人：</STRONG>Dennis Shea
<shea@ucar.edu></FONT></DIV>
<DIV><FONT size=2
face=Verdana><STRONG>发送时间：</STRONG>2013-09-19 01:13</FONT></DIV>
<DIV><FONT size=2 face=Verdana><STRONG>主题：</STRONG>Re: [ncl-talk] confidence
interval/level</FONT></DIV>
<DIV><FONT size=2
face=Verdana><STRONG>收件人：</STRONG>"朱学明"<557xiaozhu@163.com></FONT></DIV>
<DIV><FONT size=2 face=Verdana><STRONG>抄送：</STRONG>"ncl-talk@ucar.edu
USERS"<ncl-talk@ucar.edu></FONT></DIV>
<DIV><FONT size=2 face=Verdana></FONT> </DIV>
<DIV><FONT size=2 face=Verdana>
<DIV> </DIV>
<DIV>Comments on the Determination of Significance Levels </DIV>
<DIV>of the Coherence Statistic </DIV>
<DIV>Paul Julian </DIV>
<DIV>Journal of the Atmospheric Sciences, 1975 </DIV>
<DIV>Volume 12, pp836-837 </DIV>
<DIV> </DIV>
<DIV> </DIV>
<DIV>http://journals.ametsoc.org/doi/pdf/10.1175/1520-0469%281975%29032%3C0836%3ACOTDOS%3E2.0.CO%3B2 </DIV>
<DIV> </DIV>
<DIV>eg: </DIV>
<DIV> coh = .5 </DIV>
<DIV> df = 6 </DIV>
<DIV> p = 1.-(1.-coh)**(df/2.-1.) </DIV>
<DIV> print("p="+p) </DIV>
<DIV> </DIV>
<DIV> </DIV>
<DIV> </DIV>
<DIV>On 9/18/13 8:54 AM, 朱学明 wrote: </DIV>
<DIV>> Hi Dennis, </DIV>
<DIV>> can you show me how does NCL caculate the spec@coher_probability? </DIV>
<DIV>> Thanks. </DIV>
<DIV>> </DIV>
<DIV>> 2013-09-18 </DIV>
<DIV>> </DIV>
<DIV>> </DIV>
<DIV>> </DIV>
<DIV>> 朱学明 </DIV>
<DIV>> </DIV>
<DIV>> </DIV>
<DIV>> </DIV>
<DIV>> 发件人：Dennis Shea <shea@ucar.edu> </DIV>
<DIV>> 发送时间：2013-09-18 07:29 </DIV>
<DIV>> 主题：Re: [ncl-talk] confidence interval/level </DIV>
<DIV>> 收件人："朱学明"<557xiaozhu@163.com> </DIV>
<DIV>> 抄送："ncl-talk@ucar.edu USERS"<ncl-talk@ucar.edu> </DIV>
<DIV>> </DIV>
<DIV>> spec = specxy_anal(x,y,d,sm,pct) </DIV>
<DIV>> PHASE = spec@phase </DIV>
<DIV>> PHASE@_FillValue = 1e20 </DIV>
<DIV>> PHASE = where(spec@coher_probability(1).le.0.95,PHASE@_FillValue,PHASE) </DIV>
<DIV>> </DIV>
<DIV>> ========= </DIV>
<DIV>> See: http://www.ncl.ucar.edu/Applications/xy.shtml#ex25 </DIV>
<DIV>> </DIV>
<DIV>> The right (R) plot should </DIV>
<DIV>> </DIV>
<DIV>> </DIV>
<DIV>> resR = True ; plot mods desired </DIV>
<DIV>> resR@xyMarkLineModes = "Markers" ; choose which have markers </DIV>
<DIV>> resR@xyMarkers = 16 ; choose type of marker </DIV>
<DIV>> resR@xyMarkerColor = "red" ; Marker color </DIV>
<DIV>> resR@xyMarkerSizeF = 0.005 ; Marker size (default 0.01) </DIV>
<DIV>> </DIV>
<DIV>> </DIV>
<DIV>> plot = gsn_csm_xy2(wks,spec@frq,spec@coher,PHASE,resL,resR) </DIV>
<DIV>> </DIV>
<DIV>> </DIV>
<DIV>> On 9/17/13 4:04 PM, 朱学明 wrote: </DIV>
<DIV>>> Hi all, </DIV>
<DIV>>> I have tried to use the function specxy_anal get the coherance and phase of two timeseries data based on the example script spec_2.ncl. But I just want to get the coherence and phase satisfy the 0.95 confidence level, the picture likes that in the attachment. How can I do that? </DIV>
<DIV>>> It looks like that the output of function specx_ci is not what I want. </DIV>
<DIV>>> </DIV>
<DIV>>> Any help would be appreciated. Thanks. </DIV>
<DIV>>> </DIV>
<DIV>>> 2013-09-18 </DIV>
<DIV>>> </DIV>
<DIV>>> </DIV>
<DIV>>> </DIV>
<DIV>>> 朱学明 </DIV>
<DIV>>> </DIV>
<DIV>>> </DIV>
<DIV>>> </DIV>
<DIV>>> _______________________________________________ </DIV>
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