Sentences with phrase «covariance parameters»

Variance / covariance parameters for Models 2 (age interaction models) were essentially the same as those for Models 1 and so are omitted to conserve space.

An unstructured covariance matrix was used to allow for the most flexible estimation of covariance parameters between each level of spouse, visit, and time.

Estimating background error covariance parameters and assessing their impact in the OSTIA system Read more»

Not exact matches

Ilin and Kaplan (2009) and Luttinen and Ilin (2009) used iterative algorithms that make use of data throughout the record to estimate the covariance structures and other parameters of their statistical models.

(BTW, it does look to me that acf -LRB--RRB- is called with the default type parameter i.e. type is «correlation», not «covariance».

if you've got a bivariate random parameters (intercepts and age effects) up and running, and so can estimate a correlation or covariance between initial growth rate (the tree - specific random additive effect at age = 1) and tree - specific random age coefficient across the sample, the significance of that correlation / covariance would be a first crack at this without choosing an age at which to split the sample.

To select a small number of parameters conveying the maximal information about the [photon] shower shape, we uncorrelated the above parameters through a principal component analysis in which these seven parameters are transformed into new seven uncorrelated parameters given by the eigenvectors of the covariance matrix.

We initially constrained corresponding path coefficients, intercepts, and covariances to be equal for age groups and for husbands and wives and then tested whether releasing these constraints (one parameter at a time) improved model fit.

The multivariate normal prior density of the level - 2 parameters had a mean vector of zeros and a precision matrix (the inverse of the covariance matrix) with diagonal elements equal to 1.0 E \ -LRB-- \) 6 and off - diagonal elements equal to 0.

If the outcome did not have a normal distribution, then the parameter estimates of the covariance matrix were computed with robust statistics.

In these phenotypic models, the covariances between latent growth parameters as well as covariances between time - specific residuals could vary across zygosity.

Second, we executed a biometric latent growth curve model where the covariances between latent growth parameters were replaced by a Cholesky decomposition of the variance / covariance matrix of these parameters (Fig 1B).

Three nested models with increased degrees of constraint were compared in multigroup analyses (fathers versus mothers): We specified a first model of configural invariance, in which the parameters (factor loadings, item intercepts, residual variances, factor variances, and covariance) were freely estimated in each group, whereas the factor means were constrained to zero in both groups.