Sentence examples for undefined variance from inspiring English sources

One primary obstacle to the replacement of Gaussian kernels by stable kernels in models of continuous character evolution is that stable distributions have undefined variance [ 17].

The fact that stable variance is undefined means that there is no stable equivalent to standard deviation or the covariance matrix.

However, as these strategies may lead to the risk of the multivariate metrics becoming undefined or having large variance because of the small fold sizes, one needs to resort to a pooling CV strategy (these results are provided in Supplementary Tables S10 S17).

However, these solutions do not resolve the problems associated with a small or non-existent effect difference which would cause the ICER to be undefined and may make the variance intractable [ 20- 22].

As mechanical advantage is a ratio, it is Cauchy distributed: the mean is undefined and it has an infinite variance [ 27].

Genetic correlations were calculated only for traits that were observed to have significant additive genetic variance because rA is theoretically undefined when one trait has heritability equal to zero ([4]; see also [10]).

Nichols et al. [2] noted that if one observer does not detect any birds as either the primary or secondary observer the variance of the population estimate is undefined.

Division by zero is undefined.

In a simulation data file, if genes with less than half of the modal variance were selected, 77 out of 78 genes are undefined.

The inverse-variance method is problematic when there are "structural zeros" (data like ours where multiple studies have counts of zero in one or both arms of a study) because when a study contains a zero count, the study-specific log IRR and the variance of the study-specific log IRR are both undefined.

We do not recommend estimator (15) because it does not agree well with genealogical coancestries, the distribution of coancestries has more variance, and it is unstable for minor allelic frequencies close to 0 and undefined for monomorphic loci.