MATLAB Answers


to run NaN values with anova1

Asked by Charms
on 9 Sep 2019
Latest activity Commented on by Charms
on 9 Sep 2019
Hi, I have a matrix (8 x 621) and would like to run Anova1 between the 8 groups (rows). I have attached how the dataset looks like but when I run anova1, keyed in
p= anova1(dataset)
my p-value is 0. This does not seem right, may I know how I should correct it?
Thank you! :)


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1 Answer

Answer by Neuropragmatist on 9 Sep 2019
 Accepted Answer

As per the anova1 help it expects groups to be arranged in columns, not rows:
"P = anova1(M) for a matrix M treats each column as a separate group,
and determines whether the population means of the columns are equal.
This form of anova1 is appropriate when each group has the same number
of elements (balanced ANOVA)."
So by simply transposing your matrix I get:
P = anova1(testdatasetpfc_57_n1')
The problem was not actually related to the NaN values because anova1 automatically ignores them.
If you did want to remove the NaNs you could follow this procedure using the 'groups' input to anova1:
groups = repmat(1:8,size(testdatasetpfc_57_n1,2),1)';
P = anova1(testdatasetpfc_57_n1(:),groups(:))
Hope this helps,

  1 Comment

on 9 Sep 2019
wow this helped me a lot. Thank you so much! :)) really appreciate it

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