The coefficient of variation is just a normalized standard deviation (std dev / mean). It's generally only meant to be applied to data sets that are all of the same sign (all positive or all negative). You can use the ave or aave functions in Grads to compute the mean over some area or time extent. You can then use the mean to compute the spread using the popular equation for standard deviation: std dev = sqrt(1/(N-1) * sum[(x-ave(x))^2]). That should be fairly easy for you to code up. Do you need help with the coding?<br>
<br>Jeff Duda<br><br><div class="gmail_quote">On Mon, Feb 6, 2012 at 9:18 AM, Ismaila Diallo <span dir="ltr"><<a href="mailto:ismailadiallo64@yahoo.fr">ismailadiallo64@yahoo.fr</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div><div style="font-size:12pt;font-family:times new roman,new york,times,serif"><div>Hi,</div><div><br></div><div>Does someone has a grads script which can calculate the coefficient of variation or knows how to do it with grads.</div>
<div><br></div><div>Thansk in advance</div></div></div><br>_______________________________________________<br>
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<br></blockquote></div><br><br clear="all"><br>-- <br>Jeff Duda<br>Graduate research assistant<br>University of Oklahoma School of Meteorology<br>Center for Analysis and Prediction of Storms<br><br>