On Aug 5, 2010, at 4:10 AM, Ralf B wrote:
This is unbelievable. Now people like yourself start doing background
searches on one and accusing one of not being professional
Your words, not mine.
plus posting cheeky R code.
It appeared that you were having problems and did not have an
efficient strategy for searching the archives, so I shared with you
code that I developed and have put in my .Rprofile setup file. I do no
see where that is "posting cheeky R code". I saw it as trying to be
constructive. Using it would only be part of the recommended actions
to take before posting
The reason why I submitted the questions I have
submitted was that these answers did not satisfy my particular problem
(or perhaps I mistakenly thought so). The point here is that the forum
should be a forum where one should be allowed to ask questions without
first studying the history of the the entire forum in fear that
someone might have asked it before.
If you read the Posting Guide I think you will find precisely the
opposite expectation explicitly presented. Using my "cheeky code"
would only be part of the recommended actions to take before posting
if you follow the recommendations of the "Do your homework before
posting:" section. This list was not set up to be a chat room or a
tutoring center for general questions in statistics.
While you are reading the Posting Guide, please note that it expresses
this advice regarding posting messages that were sent privately:
"Take care when you quote other people's comments to respect their
rights, e.g., as summarized here. In particular
• Private messages should never be quoted without permission, "
I was hoping that I could find
clearer answers then what I was able to read. I do know how to search
in Google. But I am not an expert in statistics, as you already found
in your background check. If I would be fluent in stastitsics and R
and if past answers would have exactly satisfied my problem I would
not post here and I certainly would not have occupied your expensive
attention.
On Wed, Aug 4, 2010 at 6:16 PM, David Winsemius <dwinsem...@comcast.net
> wrote:
On Aug 4, 2010, at 5:49 PM, Ralf B wrote:
Hi R Users,
I have two vectors, x and y, of equal length representing two
types of
data from two studies. I would like to test if they are similar
enough
to use them interchangeably. No assumptions about distributions
can be
made (initial tests clearly show that they are not normal).
Here some result:
Two-sample Kolmogorov-Smirnov test
data: x and y
D = 0.1091, p-value < 2.2e-16
alternative hypothesis: two-sided
Warning message:
In ks.test(x[1:nx], y[1:nx], exact = FALSE) :
cannot compute correct p-values with ties
Here some questions:
a) What does the error message means and what does it imply?
b) The data is very noisy and the initial result shows that there is
no relation between x and y. Is there a way to calculate and effect
size?
c) Can the p-value be used, when running tests over a large amount
of
different data sets, as a metric for ranking similarity between x
and
y data sets?
There has been quite a bit of discussion on this list over the
years about
why KS test is not good in this situation. If I read the results of
a search
on your name correctly, you are in a department of Information
Sciences. I
would have thought that the first reaction of someone in that field
would be
do do a search on a question. Why are you filling up the archives
with
questions that have been repeatedly asked and answered?
Do you need help in this area?
rhelpSearch <- function(string,
restrict = c("Rhelp10", "Rhelp08", "Rhelp02",
"functions"
),
matchesPerPage = 100, ...)
RSiteSearch(string=string, restrict = restrict,
matchesPerPage =
matchesPerPage, ...)
rhelpSearch("KS.test ties p-value")
Best
R.
--
David Winsemius, MD
West Hartford, CT
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