Talk:Permutation test: Difference between revisions

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:I am getting different results form everyone else, myself. I have 80551 cases which have a difference in means which is less than or equal to the result's difference in means (and note that this includes the result), and I have 11827 cases where the difference in means is greater than the result's difference in means. My smallest difference in means is -0.518111 and my largest difference in means is 0.501556. My difference in means for the original result is 0.153222. Since other people are getting different numbers, I am curious about what these statistics look like for them (or if I have made a mistake -- which should show up in these stats). --[[User:Rdm|Rdm]] 20:42, 3 February 2011 (UTC)

::Ah, I think I see: I have 313 cases which are equal to my result, that's 0.34% of the total. I am using an epsilon of approximately 2e-16 (which is much tighter than experimental accuracy). Differing epsilons, or differences in floating point implementations for systems without epsilon are enough to account the differences I currently see on the task page --[[User:Rdm|Rdm]] 21:23, 3 February 2011 (UTC)

::Ah, I think I see: I have 313 cases which are equal to my result, that's 0.34% of the total. I am using an epsilon of result*(2^-44) which is approximately 9e-15, which is much tighter than experimental accuracy, and the largest difference between a value I classify as equal and the computed result is approximately 2e-16. Differing epsilons, or differences in floating point implementations for systems without epsilon are enough to account the differences I currently see on the task page --[[User:Rdm|Rdm]] 21:23, 3 February 2011 (UTC)

== Name of task ==