A shared table of NB deviance moments

The deviance moments w0 and w1 (see nbDevianceMoments) evaluated once on a uniform grid over log mean and log dispersion, for qlDispersion to interpolate onto every gene and cell. A caller that scores genes in blocks builds one table over the whole range and passes it to every block, so the result is invariant to how the genes are split; lookups outside the range are clamped to the edge, where the moments are asymptotically flat.

Usage

qlMomentTable(
  lmu_range,
  lphi_range,
  step_mu = 0.08,
  step_phi = 0.12,
  ngrid = NULL,
  nphi = NULL
)

Arguments

lmu_range

range of log means the table must cover, c(lo, hi).

lphi_range

range of log dispersions, c(lo, hi); a single value gives a one-row table.

step_mu, step_phi

grid spacing along log mean and log dispersion; bilinear interpolation error scales with the square of the spacing.

ngrid, nphi

explicit grid sizes, overriding the steps.

Value

a list holding the two moment matrices (log-phi rows, log-mu columns) and the grid geometry, for qlDispersion(table = ).

Examples

tab <- qlMomentTable(log(c(1e-6, 1e3)), log(c(0.1, 10)))
dim(tab$w1)
#> [1]  40 261