Message-ID: <52b33c290907200836w2826ff35q9aba42050036a20c@mail.gmail.com>
Date: 2009-07-20T15:36:21Z
From: Tormod Bøe
Subject: Automatically assign symbol for statistical significance to x given value of x
Dear r-help users,
I am using Sweave and Latex to create tables with output from several
statistical test. As an example: I have a grouping variable "group"
with two levels ("x" and "y") which I compare on variables ("a" and
"b").
I have created a table in which means, standard deviations, and the
statistic and p.value resulting from a t.test is printed. The table
looks something like:
?group(x) ? ? ? ? ? ? ? ? ?group(y)
mean ? ? ? ?sd ? ? ? ?mean ? ? ?sd ? ? t-value p-value ?sig.
mean(x,a) ?sd(x,a) mean(y,a) sd(y,a) ? ?t.a ? ? ?p.a
mean(x,b) ?sd(x,b) mean(y,b) sd(y,b) ? ?t.b ? ? ?p.b
What I would like to be able to add to this table is an indication by
means of asterisks ("*") the level of significance of the p.value(s).
I am after an expression to put in column "sig." which evaluates the
p.value and prints *, ** or *** depending on it's value (e.g. if it is
less than .05 print "*", but if it is less than .01 print "**", but if
it is less than .001 print "***", else print " ").
I am able to use a simple function like if (p.value<0.5) print("*")
else print(" "),
but I have not been able to work out how to nest the "if" expressions correctly.
Any help would be greatly appreciated.
Best regards,
Tormod B?e