..-
help for ^aov1cont^ (statalist Mar. 20, 1998)
..-
Contrasts in one-way ANOVA from means, SD's and N's
---------------------------------------------------
^aov1cont^ nvar meanvar sdvar [^if^ exp] [^in^ range]^,^
^c^oeffs^(^coeffvar^)^|^tr^end [ ^le^vel^(^#^)^ ]
Description
-----------
^aov1cont^ calculates the contrast (L) for coefficients in coeffvar over the
means in meanvar. The group sizes are in nvar and the SDs are in sdvar.
Options
-------
^coeffs(^coeffvar^)^|^trend^: one of these is REQUIRED. If ^trend^ is specified,
L is a standardized linear trend contrast using integers with spacing 1.
^level(^#^)^ defines the confidence interval coverage for L. Default: $S_level.
Remarks
-------
Like @contrast@, ^aov1cont^ calculates the standardized contrast L as
L = (a1 * mean1) + (a2 * mean2) + (a3 * mean3) + ...
where mean1 is the first value of meanvar and a1 is the first STANDARDIZED
coefficient in coeffvar, and so on. ^aov1cont^ always standardizes the coeff-
icients so that they add up to zero; it does so by subtracting the mean of
coeffvar from each of its values. The standardized coefficients (a1, a2, etc)
are labelled ^__a^ in the output from ^aov1cont^. The output includes a
confidence interval for L and a significance test for L = 0.
Examples
--------
. ^aov1cont n mean sd, coeffs(c)^
. ^aov1cont n mean sd, trend^
Stored
------
^$S_1^ total number of observations in analysis of variance
^$S_2^ number of groups in analysis of variance
^$S_3^ value of standardized contrast, L
^$S_4^ standard error of L
^$S_5^ lower confidence limit for L
^$S_6^ upper confidence limit for L
^$S_7^ t value for test of L = 0
^$S_8^ P value for test of L = 0
Also see
--------
Manual: [R] oneway
On-line: help for @oneway@, @contrast@.