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help for ^chitesti6^
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Chi-square test for univariate frequency distributions
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^chitesti6^ #obs1 #obs2 [...] [ ^\^ #exp1 #exp2 [...] ]
[ ^, nfit(^#^) replace^ ]
Description
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The input for ^chitesti6^ must consist of
either a single row of values
or two rows of values separated by a backslash ^\^.
The first row is taken to be observed frequencies, which must be zeros
or positive integers. The second row, if present, is taken to be
expected frequencies under some hypothesis, which must be positive.
These may be given either as numbers or as arithmetic expressions
without embedded spaces. If the second row is not present, the expected
frequencies are taken to be equal, i.e. equal to the mean of the
observed frequencies.
The display includes the Pearson chi-square statistic and its P-value
for a test of the hypothesis, the likelihood-ratio chi-square statistic
and its P-value, observed frequencies, expected frequencies, classic
residuals (observed - expected), and Pearson residuals, defined as
(observed - expected) / sqrt(expected).
Any cells with expected frequencies less than 5 are flagged.
^chitesti6^ requires ^chitest^ to be installed.
Options
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^nfit^ indicates the number of parameters that have been estimated from
the data. This number will be subtracted from (number of cells - 1)
to give the number of degrees of freedom. The default is 0.
^replace^ indicates that the observed and expected frequencies are to be
left as the current data in place of whatever data were there. These
variables will be called ^observed^ and ^expected^.
Examples
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. ^chitesti6 315 108 101 32 \ 312.75 104.25 104.25 34.75^
. ^chitesti6 315 108 101 32 \ 556*9/16 556*3/16 556*3/16 556*1/16^
. ^chitesti6 315 108 101 32 \ 312.75 104.25 104.25 34.75,^
^replace^
Saved values
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r(k) number of classes in distribution
r(df) degrees of freedom
r(chi2) Pearson chi-square
r(p) P-value of Pearson chi-square
r(chi2_lr) likelihood-ratio chi-square
r(p_lr) P-value of likelihood-ratio chi-square
r(emean) mean expected frequency
Author
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Nicholas J. Cox, University of Durham, U.K.
n.j.cox@@durham.ac.uk
Also see
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Manual: [U] 22 Immediate commands, [R] tabulate
On-line: help for @immed@, @tabulate@, @chitest@