<div dir="ltr">Hi ncl-talk,<div><br></div><div>Is the standard deviation computed in the "stats_dispersion" function actually a variance?</div><div><br></div><div>I test this and it appears to be variance instead of stats_dispersion as seen in with sample "a" below.</div><div><br></div><div><br></div><div><div>Variable: a </div><div>Type: float</div><div>Total Size: 56 bytes</div><div> 14 values</div><div>Number of Dimensions: 1</div><div>Dimensions and sizes:<span class="" style="white-space:pre"> </span>[ncl_join | 14] ; I had joined 8 files trends with "addfiles" function</div><div>Coordinates:</div><div>Number Of Attributes: 0</div></div><div><div>(0)<span class="" style="white-space:pre"> </span>-20.46505</div><div>(1)<span class="" style="white-space:pre"> </span>-4.795454</div><div>(2)<span class="" style="white-space:pre"> </span>-1.454606</div><div>(3)<span class="" style="white-space:pre"> </span>-2.677286</div><div>(4)<span class="" style="white-space:pre"> </span>-1.868608</div><div>(5)<span class="" style="white-space:pre"> </span>-0.4972475</div><div>(6)<span class="" style="white-space:pre"> </span>1.18715</div><div>(7)<span class="" style="white-space:pre"> </span>-1.657706</div><div>(8)<span class="" style="white-space:pre"> </span>-3.428875</div><div>(9)<span class="" style="white-space:pre"> </span>-2.766053</div><div>(10)<span class="" style="white-space:pre"> </span>-1.689298</div><div>(11)<span class="" style="white-space:pre"> </span>-0.3371645</div><div>(12)<span class="" style="white-space:pre"> </span>-0.640966</div><div>(13)<span class="" style="white-space:pre"> </span>-0.7326741</div><div><br></div><div>; ncl code compare variance to standard deviation</div><div><br></div><div>; the above data was placed into an array named "a"</div><div><div>a = (/-20.46505, -4.795454, -1.454606,-2.677286, -1.868608, -0.4972475, 1.18715, -1.657706, -3.428875, -2.766053, -1.689298, -0.3371645, -0.640966, -0.7326741/)</div><div><br></div><div><br></div><div>; Input</div><div>Var_a = variance(a) ; calc variance</div><div>print(Var_a)</div><div>StdDev_a = stddev(a) ; calc standard deviation</div><div>print(StdDev_a)</div></div><div><div>opt = True</div><div>opt@PrintStat = True</div><div>Stats_a = stat_dispersion(a,opt)</div></div><div><br></div><div><br></div><div>; Output</div><div>; from individually calculating Variance<br></div><div><div>Variable: Var_a</div><div>Type: float</div><div>Total Size: 4 bytes</div><div> 1 values</div><div>Number of Dimensions: 1</div><div>Dimensions and sizes:<span class="" style="white-space:pre"> </span>[1]</div><div>Coordinates:</div><div>(0)<span class="" style="white-space:pre"> </span>27.49021</div><div><br></div><div>; from individually calculating Standard Deviation</div><div>Variable: StdDev_a</div><div>Type: float</div><div>Total Size: 4 bytes</div><div> 1 values</div><div>Number of Dimensions: 1</div><div>Dimensions and sizes:<span class="" style="white-space:pre"> </span>[1]</div><div>Coordinates:</div><div>(0)<span class="" style="white-space:pre"> </span>5.243111</div></div><div><br></div><div>; from Stats_Dispersion function.</div><div>(0)</div><div>(0)<span class="" style="white-space:pre"> </span> ===> Robust Dispersion Statistics <===</div><div>(0)<span class="" style="white-space:pre"> </span> [0] Mean=-2.98742</div><div>(0)<span class="" style="white-space:pre"> </span> [1] StdDev=27.4902 ; this appears to be variance since</div><div>(0)<span class="" style="white-space:pre"> </span> [2] Min=-20.4651</div><div>(0)<span class="" style="white-space:pre"> </span> [3] LowDec=-20.4651</div><div>(0)<span class="" style="white-space:pre"> </span> [4] LowOct=-20.4651</div><div>(0)<span class="" style="white-space:pre"> </span> [5] LowSex=-4.79545</div><div>(0)<span class="" style="white-space:pre"> </span> [6] LowQuartile=-3.42888</div><div>(0)<span class="" style="white-space:pre"> </span> [7] LowTri=-2.76605</div><div>(0)<span class="" style="white-space:pre"> </span> [8] Median=-1.6735</div><div>(0)<span class="" style="white-space:pre"> </span> [9] HighTri=-1.45461</div><div>(0)<span class="" style="white-space:pre"> </span> [10] HighQuartile=-0.732674</div><div>(0)<span class="" style="white-space:pre"> </span> [11] HighSex=-0.640966</div><div>(0)<span class="" style="white-space:pre"> </span> [12] HighOct=-0.497248</div><div>(0)<span class="" style="white-space:pre"> </span> [13] HighDec=-0.497248</div><div>(0)<span class="" style="white-space:pre"> </span> [14] Max=1.18715</div><div>(0)<span class="" style="white-space:pre"> </span> [15] Range=21.6522</div><div>(0)<span class="" style="white-space:pre"> </span> [16] Dispersion=0.787633</div><div>(0)<span class="" style="white-space:pre"> </span> [17] RMS Anomaly=5.05239</div><div>(0)<span class="" style="white-space:pre"> </span> [18] # Total=14</div><div>(0)<span class="" style="white-space:pre"> </span> [19] # Used=14</div><div>(0)<span class="" style="white-space:pre"> </span> [20] # Missing=0</div><div>(0)<span class="" style="white-space:pre"> </span> [21] % Missing=0</div><div>(0)<span class="" style="white-space:pre"> </span> [22] Lower 0.1%=9.96921e+36</div><div>(0)<span class="" style="white-space:pre"> </span> [23] Lower 1.0%=9.96921e+36</div><div>(0)<span class="" style="white-space:pre"> </span> [24] Lower 5.0%=9.96921e+36</div><div>(0)<span class="" style="white-space:pre"> </span> [25] Upper 5.0%=9.96921e+36</div><div>(0)<span class="" style="white-space:pre"> </span> [26] Upper 1.0%=9.96921e+36</div><div>(0)<span class="" style="white-space:pre"> </span> [27] Upper 0.1%=9.96921e+36</div><div>(0)<span class="" style="white-space:pre"> </span> [28] Skewness=-2.57898</div><div>(0)<span class="" style="white-space:pre"> </span> [29] Kurtosis=5.86411</div></div><div><br></div><div><br></div><div>What do you think?</div><div><br></div><div>Thank you for time and assistance,<br></div><div><br></div><div><div><div><div class="gmail_signature"><div dir="ltr"><div><div dir="ltr"><font color="#0000ff"><i>Rainer Luptowitz</i></font><div><font color="#0000ff"><i>Grad Student </i></font><div><font color="#0000ff"><i>Dept Earth Sciences</i></font></div><div><font color="#0000ff"><i>UC Riverside</i></font></div><div><a href="mailto:rlupt001@ucr.edu" target="_blank"><font color="#0000ff"><i>rlupt001@ucr.edu</i></font></a></div><div><br></div></div></div></div></div></div></div>
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