Diff for /imach/html/doc/biaspar-cov.htm between versions 1.3 and 1.4

version 1.3, 2006/02/09 15:20:33 version 1.4, 2015/08/04 07:14:48
Line 1 Line 0
 <body>  
 <title>IMaCh Cov rbiaspar.txt</title>  
  <font size="2">Imach version 0.98b, January 2006, INED-EUROREVES  <br> $Revision$ $Date$</font> <hr size="2" color="#EC5E5E">  
 Title=1st_example <br>Datafile=data1.txt Firstpass=1 Lastpass=4 Stepm=1 Weight=0 Model=.<br>  
   
 <h4>Matrix of variance-covariance of pairs of step probabilities</h4>  
   file biaspar-cov.htm<br>  
   
 Ellipsoids of confidence centered on point (p<inf>ij</inf>, p<inf>kl</inf>) are estimatedand drawn. It helps understanding how is the covariance between two incidences. They are expressed in year<sup>-1</sup> in order to be less dependent of stepm.<br>  
   
 <br> Contour plot corresponding to x'cov<sup>-1</sup>x = 4 (where x is the column vector (pij,pkl)) are drawn. It can be understood this way: if pij and pkl where uncorrelated the (2x2) matrix of covariance would have been (1/(var pij), 0 , 0, 1/(var pkl)), and the confidence interval would be 2 standard deviations wide on each axis. <br> Now, if both incidences are correlated (usual case) we diagonalised the inverse of the covariance matrix and made the appropriate rotation to look at the uncorrelated principal directions.<br>To be simple, these graphs help to understand the significativity of each parameter in relation to a second other one.<br>  
   
 <br>Ellipsoids of confidence cov(p13,p12) expressed in year<sup>-1</sup> :<a href="biaspar/varpijgrbiaspar113-12.png">biaspar/varpijgrbiaspar113-12.png</A>,  
 <br><img src="biaspar/varpijgrbiaspar113-12.png">  
 <br> Correlation at age 65 (-0.367), 70 (-0.389), 75 (-0.431), 80 (-0.474), 85 (-0.418), 90 (-0.361), 95 (-0.348),  
 <br>Ellipsoids of confidence cov(p21,p12) expressed in year<sup>-1</sup> :<a href="biaspar/varpijgrbiaspar121-12.png">biaspar/varpijgrbiaspar121-12.png</A>,  
 <br><img src="biaspar/varpijgrbiaspar121-12.png">  
 <br> Correlation at age 65 (0.332), 70 (0.327), 75 (0.317), 80 (0.292), 85 (0.282), 90 (0.309), 95 (0.322),  
 <br>Ellipsoids of confidence cov(p23,p12) expressed in year<sup>-1</sup> :<a href="biaspar/varpijgrbiaspar123-12.png">biaspar/varpijgrbiaspar123-12.png</A>,  
 <br><img src="biaspar/varpijgrbiaspar123-12.png">  
 <br> Correlation at age 65 (0.370), 70 (0.393), 75 (0.427), 80 (0.453), 85 (0.359), 90 (0.260), 95 (0.246),  
 <br>Ellipsoids of confidence cov(p21,p13) expressed in year<sup>-1</sup> :<a href="biaspar/varpijgrbiaspar121-13.png">biaspar/varpijgrbiaspar121-13.png</A>,  
 <br><img src="biaspar/varpijgrbiaspar121-13.png">  
 <br> Correlation at age 65 (0.050), 70 (0.040), 75 (0.025), 80 (0.023), 85 (0.081), 90 (0.109), 95 (0.105),  
 <br>Ellipsoids of confidence cov(p23,p13) expressed in year<sup>-1</sup> :<a href="biaspar/varpijgrbiaspar123-13.png">biaspar/varpijgrbiaspar123-13.png</A>,  
 <br><img src="biaspar/varpijgrbiaspar123-13.png">  
 <br> Correlation at age 65 (-0.471), 70 (-0.504), 75 (-0.560), 80 (-0.594), 85 (-0.519), 90 (-0.462), 95 (-0.418),  
 <br>Ellipsoids of confidence cov(p23,p21) expressed in year<sup>-1</sup> :<a href="biaspar/varpijgrbiaspar123-21.png">biaspar/varpijgrbiaspar123-21.png</A>,  
 <br><img src="biaspar/varpijgrbiaspar123-21.png">  
 <br> Correlation at age 65 (-0.044), 70 (-0.040), 75 (-0.035), 80 (-0.035), 85 (-0.059), 90 (-0.083), 95 (-0.079),  
   

Removed from v.1.3  
changed lines
  Added in v.1.4


FreeBSD-CVSweb <freebsd-cvsweb@FreeBSD.org>