<div dir="ltr"><div><div><div>I would say so ... However, to be upfront, I am not sure of he original question. <br><br></div>Note that correlations are bounded [-1 to +1]. Hence, not 'normally distributed.' Usually, the correlations are put into a normal distribution via the Fischer z-transform. Means and std dev are in 'z-space'; the results are transformed back<br> <br></div> Look at the example for <br> <a href="https://www.ncl.ucar.edu/Document/Functions/Built-in/escorc.shtml">https://www.ncl.ucar.edu/Document/Functions/Built-in/escorc.shtml</a><br><br></div>It uses the large sample size z-value1.96 ... you can use the tvalue since tval ==> zval for large sample size<br><div><pre> zlow = z - 1.96*se ; 95% (2.58 for 99%)
zhi = z + 1.96*se
</pre><br><br><br><div><br><br></div></div></div><div class="gmail_extra"><br><div class="gmail_quote">On Tue, Apr 4, 2017 at 2:07 PM, Andrew Kren - NOAA Affiliate <span dir="ltr"><<a href="mailto:andrew.kren@noaa.gov" target="_blank">andrew.kren@noaa.gov</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">Thanks Dennis,<div>In general, can the ttest be run on anomaly correlations?</div></div><div class="HOEnZb"><div class="h5"><div class="gmail_extra"><br><div class="gmail_quote">On Tue, Apr 4, 2017 at 2:01 PM, Dennis Shea <span dir="ltr"><<a href="mailto:shea@ucar.edu" target="_blank">shea@ucar.edu</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><div><div><div><div>Has anybody answered your question?<br><br><a href="http://www.itl.nist.gov/div898/handbook/eda/section3/eda352.htm" target="_blank">http://www.itl.nist.gov/div898<wbr>/handbook/eda/section3/eda352.<wbr>htm</a><br></div>See the definition of the confidene interval.<br><br> tval_opt =True ; p & t-value<br> pt = ttest(aveX,varX,sX, aveY,varY,sY, iflag, tval_opt)<br></div> print(pt)<br><br></div>The 2nd element is the t-value<br><br></div>HTH<br><div><br><div><div><br><br><div><br></div></div></div></div></div><div class="gmail_extra"><br><div class="gmail_quote"><div><div class="m_-5599711679072778743h5">On Fri, Mar 31, 2017 at 3:49 PM, Andrew Kren - NOAA Affiliate <span dir="ltr"><<a href="mailto:andrew.kren@noaa.gov" target="_blank">andrew.kren@noaa.gov</a>></span> wrote:<br></div></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div><div class="m_-5599711679072778743h5"><div dir="ltr">Dear ncl-talk,<div><br></div><div>I'm using the function ttest in NCL to compute the two-tailed significance of a set of correlations. I plot the correlations (anomaly) as a time series as most people do. I compute the difference between the two and want to also plot an envelope that encompasses the 95% confidence range for the range of values. Is there a way to determine this from the ttest? <span class="m_-5599711679072778743m_2612023742121366583HOEnZb"><font color="#888888"><br clear="all"><div><br></div>-- <br><div class="m_-5599711679072778743m_2612023742121366583m_7185588501146775571gmail_signature" data-smartmail="gmail_signature"><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div><div>Andrew Kren, PhD<br>
Research Scientist I, Global Observing Systems Analysis (GOSA) Group<br>
NOAA ESRL Global Systems Division (Rm 3C515)<br>
325 Broadway, Boulder, CO 80305<br>
<a href="tel:%28303%29%20497-5418" value="+13034975847" target="_blank">(303) 497-5418</a><span><font color="#888888"><br>
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</blockquote></div><br><br clear="all"><div><br></div>-- <br><div class="m_-5599711679072778743gmail_signature" data-smartmail="gmail_signature"><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div><div>Andrew Kren, PhD<br>
Research Scientist I, Global Observing Systems Analysis (GOSA) Group<br>
NOAA ESRL Global Systems Division (Rm 3C515)<br>
325 Broadway, Boulder, CO 80305<br>
<a href="tel:%28303%29%20497-5418" value="+13034975847" target="_blank">(303) 497-5418</a><span><font color="#888888"><br>
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