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*To*: asreml@ram.chiswick.anprod.csiro.au*Subject*: Re: Interpretation of Components for Splines*From*: "Peter M. Saama" <saama@pilot.msu.edu>*Date*: Fri, 30 Apr 1999 11:25:22 -0400*In-Reply-To*: <Pine.SUN.3.91.990430075503.6154t-100000@wagsun>*References*: <4.1.19990429102819.00ae2230@gogreen.ans.msu.edu>*Sender*: asreml-owner@ram.chiswick.anprod.csiro.au

>The component for spl(time) is a variance component, but it controls the >amount of smoothing. If this component (actually the ratio gamma) tends >to zero, the spline fit tends to a straight line, as it gets large the >fit tends to interpolation. The additional variance component, ie >dev(time), allows for the presence of group effects, and can only be >fitted if there is replication at each (or most) time point. This is in >line with the usual one-way random effects analysis where you would fit >y~ mu !r group >in asreml to get correct analysis ie estimating both an error and between >groups variance. > >The usual roughness penalty that is described in most smoothing texts is >actually lambda = 1/gamma(spl). Thank you for your remarks. As you know, it is customary to specify heritability as a function of the genetic and total variability. In formulating linear functions of the variance components, should the components for spl(time) and dev(time) be considered a part of the total variability or should one include them in the genetic variation? Peter / >........................................................................... .... > Brian Cullis Tel: 02 6938 1855 > NSW Agriculture Fax: 02 6938 1809 > Wagga Agricultural Institute email: brian.cullis@agric.nsw.gov.au > Pine Gully Rd > WAGGA WAGGA NSW 2650 -- Asreml mailinglist archive: http://www.chiswick.anprod.csiro.au/lists/asreml

**Follow-Ups**:**Re: Interpretation of Components for Splines***From:*bsouthey@iastate.edu

**Re: Interpretation of Components for Splines***From:*"B. Cullis" <cullisb@wagsun.agric.nsw.gov.au>

**References**:**Re: Interpretation of Components for Splines***From:*"B. Cullis" <cullisb@wagsun.agric.nsw.gov.au>

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