Skip to main content
. 2012 Jan 24;22(1):013111–013111-25. doi: 10.1063/1.3675621

TABLE I.

Summary of all the non-TDMI based metrics used to assess homogeneity in a population (both among the graphs and the supports) used to verify the TDMI-type analysis.

non-TDMI-based quantities for characterizing a population
Hx¯ difference between the population and individual element means ∼0 implies either (1) most elements have a similar number of measurements or (2) the individuals come from distributions with similar means; 0 implies the converse
V(f(n)) variance of the PDF of the number of measurements per individual (1) V ∼ 0, Hx¯~0 imply elements were measured similarly; 0, Hx¯~0 implies elements measured at different rates; 0, Hx¯0 implies elements measured at different rates with differing source distributions
s¯min E[smin(i)] lower support boundary mean
s¯max E[smax(i)] upper support boundary mean
Vsmin Var(smin) lower support boundary variance
Vsmax Var(smax) upper support boundary variance
|S|¯ s¯max-s¯min length of support mean.
V|S|¯ Var(s¯max-s¯min) length of support variance
HRA area between the (point-wise) least and greatest PDF graph quantifies variance between the PDFs of the population; ∼0 implies element PDFs are homogeneous; very sensitive
VS(p) SE[(p(x))2]-E[p(x)]2dx, variance of the PDFs relative to a specified support, S ∼0 implies homogeneity in PDFs; larger VarS(f) implies greater heterogeneity in the PDFs.
VS^(p) VS(p) calculated relative to the support of the aggregate population; S^=i=1NS^i; note that there does exist an aggregate normalized support, S^, but we will not use this quantity here. VS^(p) has the same interpretation as VS(p) in general, but has the potential to include support-based effects.
VS¯(p) VS(p) calculated relative to the abstract support of the population, S¯ VS¯(p) has the same interpretation as VS(p) in general, but excludes support-based effects.