Creates a sparse mean-shape specification for the balanced simulation
functions. End each cell definition with value. Unlisted cells have raw
value zero, and factors in the tested term that are omitted from every row
are broadcast when the pattern is resolved against a design.
Arguments
- ...
Repeated named sparse-cell definitions. Each definition must use the same factor names in the same order and end in a finite numeric scalar named
value. Factor levels may be supplied as one-based integer indices (for example,time = 3) or as the generated balanced-design names (for example,time = "time3"). The two forms are equivalent after the pattern is resolved against a design.
Value
An object of class anovapowersim_means_pattern, retaining the
sparse definitions until a balanced simulation function resolves them
against its design and tested term.
Details
Pattern values describe relative shape, not effect magnitude. The selected
power function projects the raw values onto the requested ANOVA term,
normalizes that component, and rescales it uniformly to reach target_pes.
Multiplying all values by one positive constant, adding an intercept or a
lower-order component, or reversing every sign therefore leaves the same
target-term direction (up to sign). Under nonsphericity, different
directions within a multi-df term can nevertheless produce different
simulated power.
This differs from cell_design(), where each m is a literal population
mean whose magnitude directly determines the simulated effect.
Default direction
When no pattern is supplied, balanced simulations use centered scores in
generated level order, i - (L + 1) / 2 for levels i = 1, ..., L,
normalized to unit length. Interactions use the Kronecker product of their
factors' normalized score vectors, followed by one final normalization after
broadcasting. This is an ordered, reproducible convention rather than a
neutral scientific assumption; an explicit pattern is recommended whenever
the expected shape is known.
See also
cell_design() for unbalanced designs with literal cell means.