Re: [R] t-test for regression estimate

2016-06-29 Thread Fox, John
Dear Steven, > -Original Message- > From: Steven Yen [mailto:sye...@gmail.com] > Sent: June 29, 2016 9:48 AM > To: Fox, John <j...@mcmaster.ca> > Cc: R-help <r-help@r-project.org>; Sandy Weisberg (sa...@umn.edu) > <sa...@umn.edu> > Subject: Re: [R] t

Re: [R] t-test for regression estimate

2016-06-29 Thread Fox, John
Dear Steven, > -Original Message- > From: Steven Yen [mailto:sye...@gmail.com] > Sent: June 29, 2016 9:39 AM > To: Fox, John <j...@mcmaster.ca> > Cc: R-help <r-help@r-project.org>; Sandy Weisberg (sa...@umn.edu) > <sa...@umn.edu> > Subject:

Re: [R] t-test for regression estimate

2016-06-29 Thread Steven Yen
othesis for more >> information. >> >> Best, >> John >> >>> -Original Message- >>> From: Steven Yen [mailto:sye...@gmail.com] >>> Sent: June 28, 2016 3:44 PM >>> To: Fox, John<j...@mcmaster.ca> >>> Cc: R-help<r-help@

Re: [R] t-test for regression estimate

2016-06-29 Thread Steven Yen
> From: Steven Yen [mailto:sye...@gmail.com] >> Sent: June 28, 2016 3:44 PM >> To: Fox, John <j...@mcmaster.ca> >> Cc: R-help <r-help@r-project.org> >> Subject: Re: [R] t-test for regression estimate >> >> Thanks John. Reason is I am doin

Re: [R] t-test for regression estimate

2016-06-29 Thread Fox, John
n. Best, John > -Original Message- > From: Steven Yen [mailto:sye...@gmail.com] > Sent: June 28, 2016 3:44 PM > To: Fox, John <j...@mcmaster.ca> > Cc: R-help <r-help@r-project.org> > Subject: Re: [R] t-test for regression estimate > > Thanks John. Reason is I a

Re: [R] t-test for regression estimate

2016-06-29 Thread BONACHE Adrien via R-help
, copy paste the code in a new function and save your code. Regards, Adrien. De : Steven Yen <sye...@gmail.com> À : "Fox, John" <j...@mcmaster.ca> Cc : R-help <r-help@r-project.org> Envoyé le : Mercredi 29 juin 2016 0h43 Objet : Re: [R] t-test for regress

Re: [R] t-test for regression estimate

2016-06-28 Thread Steven Yen
, > John > > - > John Fox, Professor > McMaster University > Hamilton, Ontario > Canada L8S 4M4 > Web: socserv.mcmaster.ca/jfox > > >> -Original Message- >> From: R-help [mailto:r-help-boun...@r-project.org] On Behalf Of

Re: [R] t-test for regression estimate

2016-06-28 Thread Fox, John
, Professor McMaster University Hamilton, Ontario Canada L8S 4M4 Web: socserv.mcmaster.ca/jfox > -Original Message- > From: R-help [mailto:r-help-boun...@r-project.org] On Behalf Of Steven Yen > Sent: June 28, 2016 9:27 AM > To: R-help <r-help@r-project.org> >

Re: [R] t-test for regression estimate

2016-06-28 Thread Viechtbauer Wolfgang (STAT)
> Yen > Sent: Tuesday, June 28, 2016 18:27 > To: R-help > Subject: [R] t-test for regression estimate > > test option for linearHypothesis in library(car) include "Chisq" and > "F". I prefer a simple t-test so that I can retrieve the standard error. &g

[R] t-test for regression estimate

2016-06-28 Thread Steven Yen
test option for linearHypothesis in library(car) include "Chisq" and "F". I prefer a simple t-test so that I can retrieve the standard error. Any options other than linearHypothesis to test the linear hypothesis (with 1 restriction/degree of freedom)? > summary(ols1) Coefficients:

Re: [R] t-test: many changing groups.

2015-03-08 Thread Adams, Jean
Hard to disentangle your code in the non-HTML world of r-help. Please use plain text in the future. Below is one approach you could try. Jean # response variables resp_vars - runif(20) names(resp_vars) - paste0(sample_, seq(20)) # independent variables ind_vars - matrix(sample(c(A, B), 2000,

[R] t-test: many changing groups.

2015-03-07 Thread White Sky
I'd like to perform a t-test between groups 'A' and 'B'. The difficulty is that although there is only one response variable, there are many observations, and the grouping (A or B) differs with each observation. My code for generating the input data is shown below. I'd like to know how to

[R] t test for multiple classes

2013-12-20 Thread Luigi Marongiu
dear all, I have a dataset composed by different classes: I have two main classes, active (Act.) and latent (Lat.), furher subdivided in the gene subclasses IP10 and MIG and then into 7 stimulus sub-subclasses ESAT6 to PHA. Would it be possible to test in a direct way the statistical differences

[R] t-test across columns

2013-07-15 Thread Nico Met
Dear all, I would like to do t-test across two columns name with different cat with overall mean (val). (Removing if there is a single observation) And finally, make a matrix with t-value and p-value associated with a name (in rows) and cat (in columns) dput(x) structure(list(name =

Re: [R] t-test across columns

2013-07-15 Thread arun
15.9   NA   NA   NA   NA A.K. - Original Message - From: Nico Met nicome...@gmail.com To: R help r-help@r-project.org Cc: Sent: Monday, July 15, 2013 11:50 AM Subject: [R] t-test across columns Dear all, I would like to do t-test across two

Re: [R] t-test across columns

2013-07-15 Thread David Carlson
Texas AM University College Station, TX 77840-4352 -Original Message- From: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org] On Behalf Of Nico Met Sent: Monday, July 15, 2013 10:50 AM To: R help Subject: [R] t-test across columns Dear all, I would like to do t-test

Re: [R] t-test across columns

2013-07-15 Thread arun
Met' nicome...@gmail.com; 'R help' r-help@r-project.org Cc: Sent: Monday, July 15, 2013 1:33 PM Subject: Re: [R] t-test across columns This may be close to what you want: t.val - by(x, x$cat, function(y) if (min(table(y$name)1)) { +      t.test(val~name, y)}) t.out - do.call(rbind, sapply

[R] T test for Single Mean

2013-06-19 Thread Sparks, John James
Dear R Helpers, I am stuck on some syntax and I thought that I was following one of the examples that I found out there quite faithfully. I just want to know how to do a t test on a single mean for whether or not it is greater than a specific value. So I am using the data set sleep and I want

Re: [R] T test for Single Mean

2013-06-19 Thread Bert Gunter
(Re-) Read the docs (e.g. Intro to R, R Language Definition) . ... arguments have to be named! t.test(sleep$extra,mu=0, alt = greater) ## works -- Bert On Wed, Jun 19, 2013 at 6:50 AM, Sparks, John James jspa...@uic.edu wrote: Dear R Helpers, I am stuck on some syntax and I thought that I

[R] t-test behavior given that the null hypothesis is true

2013-01-09 Thread Pavlos Pavlidis
Dear all, I observer a strange behavior of the pvalues of the t-test under the null hypothesis. Specifically, I obtain 2 samples of 3 individuals each from a normal distribution of mean 0 and variance 1. Then, I calculate the pvalue using the t-test (var.equal=TRUE, samples are independent). When

Re: [R] t-test behavior given that the null hypothesis is true

2013-01-09 Thread Ted Harding
On 09-Jan-2013 08:50:46 Pavlos Pavlidis wrote: Dear all, I observer a strange behavior of the pvalues of the t-test under the null hypothesis. Specifically, I obtain 2 samples of 3 individuals each from a normal distribution of mean 0 and variance 1. Then, I calculate the pvalue using the

Re: [R] t-test behavior given that the null hypothesis is true

2013-01-09 Thread Ted Harding
Ah! You have aqssigned a parameter equal.var=TRUE, and equal.var is not a listed paramater for t.test() -- see ?t.test : t.test(x, y = NULL, alternative = c(two.sided, less, greater), mu = 0, paired = FALSE, var.equal = FALSE, conf.level = 0.95, ...) Try it instead with

Re: [R] t-test

2012-10-05 Thread Nico Met
: R help Subject: Re: [R] t-test Hi John, You are right. With more than two groups, the type 1 error rate should be a problem. A.K. - Original Message - From: John Kane jrkrid...@inbox.com To: arun smartpink...@yahoo.com Cc: Sent: Thursday, October 4, 2012 8:40 AM Subject: Re

[R] t-test

2012-10-04 Thread Nico Met
Dear Group, I want to do a t-test calculation on a large data set. I am pasting some part of it structure(list(Name = structure(c(1L, 1L, 1L, 1L, 1L, 1L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L), .Label = c(CTK100, CTK103, CTK121), class = factor), Score =

Re: [R] t-test

2012-10-04 Thread Rui Barradas
Hello, I'm not quite sure I understand, but something like this? tapply(dat$Score, dat$Name, FUN = mean) sapply(unique(dat$Name), function(un){ with(dat, t.test(Score[Name == un], Score[Name != un])$p.value)}) My doubt is in what you mean by mean for CTK and all. The ?t.test gives a

Re: [R] t-test

2012-10-04 Thread Nico Met
Dear Rui, Many thanks for help. mean for CTK and all = comparison between mean of all groups ( which means second col) vs. each groups like CTK100, CTK121 etc. Regards Nico On Thu, Oct 4, 2012 at 12:28 PM, Rui Barradas ruipbarra...@sapo.pt wrote: Hello, I'm not quite sure I understand,

Re: [R] t-test

2012-10-04 Thread arun
-h...@stat.math.ethz.ch Sent: Thursday, October 4, 2012 6:37 AM Subject: Re: [R] t-test Dear Rui, Many thanks for help. mean for CTK and all  = comparison between mean of all groups ( which means second col) vs. each groups like CTK100, CTK121 etc. Regards Nico On Thu, Oct 4, 2012 at 12:28 PM

Re: [R] t-test

2012-10-04 Thread arun
Hi John, You are right.  With more than two groups, the type 1 error rate should be a problem. A.K. - Original Message - From: John Kane jrkrid...@inbox.com To: arun smartpink...@yahoo.com Cc: Sent: Thursday, October 4, 2012 8:40 AM Subject: Re: [R] t-test My stats are lousy but isnt

Re: [R] t-test

2012-10-04 Thread Jose Iparraguirre
- From: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org] On Behalf Of arun Sent: 04 October 2012 13:59 To: John Kane Cc: R help Subject: Re: [R] t-test Hi John, You are right.  With more than two groups, the type 1 error rate should be a problem. A.K. - Original Message

[R] t-test on a data-frame.

2011-07-14 Thread Economics Student
Dear R-helpers, In a data frame I have 100 securities,monthly closing value,from 1995 to present,which I have to 1. Sampling with replacement,make 50 samples of 10 securities each,each sample hence will be a data frame with 10 columns. 2. With uniform probabilty,mark a month from 2000 onwards as

Re: [R] t-test on a data-frame.

2011-07-14 Thread Sarah Goslee
Hi Student (since you have no other name), On Thu, Jul 14, 2011 at 6:42 AM, Economics Student economicsstudent2...@gmail.com wrote: Dear R-helpers, In a data frame I have 100 securities,monthly closing value,from 1995 to present,which I have to 1. Sampling with replacement,make 50 samples

[R] t-test calculation correct?

2011-01-17 Thread Sascha Vieweg
A multinomial logit model (N=192) revealed (besides others) the following statistics for the outcome, y, and one predictor, x: - y = A (baseline, n=34) - y = B (n=26), B(x)=0.7323 (SE=0.2384) - y = C (n=132), B(x)=0.6535 (SE=0.2041) With a t-test I want to explore whether the two predictors

Re: [R] t-test calculation correct?

2011-01-17 Thread Bert Gunter
As this is apparently a post hoc test, this is wrong. The results are biased. You have provided a nice example of how to do irreproducible science. Consult a local statistician for what this means if you do not know. -- Bert Gunter On Mon, Jan 17, 2011 at 4:35 AM, Sascha Vieweg

Re: [R] t-test or ANOVA...who wins? Help please!

2011-01-05 Thread Tal Galili
Hello Frodo, It is not clear to me from your questions some of the basics of your analysis. If you only have two levels of a factor, and one response - why in the anova do you use more factors (and their interactions)? In that sense, it is obvious that your results would differ from the t-test.

Re: [R] t-test or ANOVA...who wins? Help please!

2011-01-05 Thread Frodo Jedi
and understand. Please enlighten me. Thanks in advance Best regards From: Tal Galili tal.gal...@gmail.com To: Frodo Jedi frodo.j...@yahoo.com Cc: r-help@r-project.org Sent: Wed, January 5, 2011 10:15:41 AM Subject: Re: [R] t-test or ANOVA...who wins? Help

[R] t-test or ANOVA...who wins? Help please!

2011-01-04 Thread Frodo Jedi
Dear all, I need an help because I don´t know how to perform the analysis in the right way, as I get different beheaviors using t-test and two ways ANOVA. In what follow I post the table, my goal and the strange results I got. I kindly ask you an help because I really don´t know how to solve

Re: [R] t-test problem

2010-06-17 Thread Worik R
Sorry, I realized that is is fairly easy to test that it is an issue with which tail of the distribution you use. This should show what is going on better than my prior message. 1.353946/2 = 0.676973 1 - 0.676973 = 0.323027 0.323027 * 2 = 0.646054 in pt(), the default is lower.tail=TRUE.

Re: [R] t-test problem

2010-06-17 Thread David Winsemius
On Jun 17, 2010, at 12:51 AM, Worik R wrote: If it were not for the fact that I get inconsistent results I would be sure that I need... I have not yet seen a proper challenge to your original assumption that the t-statistic should be the same as the p-value. They go in _opposite_

Re: [R] t-test problem

2010-06-17 Thread Oscar Rueda
Hi Worik, You can try 2*pt(abs(t1$statistic), t1$parameter, lower.tail=FALSE) If the test is two sided. Cheers, Oscar Oscar M. Rueda, PhD Postdoc, Breast Cancer Functional Genomics Cancer Research UK Cambridge Research Institute Li Ka Shing Centre Robinson Way Cambridge CB2 0RE England

Re: [R] t-test problem

2010-06-17 Thread Ted Harding
On 16-Jun-10 22:30:39, Worik R wrote: I have two pairs of related vectors x1,y1 and x2,y2 I wish to do a test for differences in means of x1 and y1, ditto x2 and y2. I am getting odd results. I am not sure I am using 'pt' properly... I have not included the raw vectors as they

Re: [R] t-test problem

2010-06-17 Thread Worik R
Ted this was very helpful. To be crystal clear I'll rephrase you. What I am interested in is the probability that my 'T' is in the tail. For a two sided test I do not care which tail. Since (all things being equal) the distribution of T is around 0 if the my T is greater than 0 I compare it to

[R] t-test problem

2010-06-16 Thread Worik R
I have two pairs of related vectors x1,y1 and x2,y2 I wish to do a test for differences in means of x1 and y1, ditto x2 and y2. I am getting odd results. I am not sure I am using 'pt' properly... I have not included the raw vectors as they are long. I am interested if I am using R

Re: [R] t-test problem

2010-06-16 Thread Worik R
If it were not for the fact that I get inconsistent results I would be sure that I need... 2*pt(stat, df) Section 8.1 of R-intro.pdf is explicit. Problem is it gives inconsistent results Worik On Thu, Jun 17, 2010 at 10:30 AM, Worik R wor...@gmail.com wrote: I have two pairs of related

Re: [R] t-test problem

2010-06-16 Thread Worik R
More: When the t-stat is 0 should I use 'pt' differently? I have been checking my results and (except for the example I posted) all the inconsistencies occur when t0 Worik On Thu, Jun 17, 2010 at 10:30 AM, Worik R wor...@gmail.com wrote: I have two pairs of related vectors x1,y1 and

Re: [R] t-test problem

2010-06-16 Thread Joshua Wiley
Look what happens when you use lower.tail=FALSE (see ?pt ). If that is not your problem, perhaps you can provide a short sample vector that replicates your results? Josh On Wed, Jun 16, 2010 at 10:02 PM, Worik R wor...@gmail.com wrote: More: When the t-stat is 0 should I use 'pt'

Re: [R] t-test problem

2010-06-16 Thread Joshua Wiley
On Wed, Jun 16, 2010 at 3:30 PM, Worik R wor...@gmail.com wrote: I have two pairs of related vectors x1,y1 and x2,y2 I wish to do a test for differences in means of x1 and y1, ditto x2 and y2. I am getting odd results.  I am not sure I am using 'pt' properly... I have not included the

Re: [R] T-test for loop

2010-05-06 Thread Dimitri Liakhovitski
Sounds like homework (you are not supposed to post homework-related questions here - read the guidelines). But anyway: nr.of.rejections=0 for(i in 1:1){ x=rnorm(10, 0.1, 1) result-t.test(x,alternative=greater,mu=0,conf.level=0.95)$p.value if(result0.05) nr.of.rejections =

Re: [R] T-test for loop

2010-05-06 Thread Joris Meys
Hehe, those homeworks. If you can explain this code to the professor, you surely passed. n -1 obs.rej.rate - sum(sapply(1:n,function(x){t.test(rnorm(10, 0.1, 1),alternative=greater,mu=0,conf.level=0.95)$p.value 0.05}))/n obs.rej.rate This could actually be another round of R-golf. Anybody

Re: [R] T-test for loop

2010-05-06 Thread Joris Meys
PS : level, you might want to consider stopping to spam the help-list. You're not making yourself popular by asking -in one day- 3 questions that can be solved by using Google and reading the introductions given on the R homepage. On Thu, May 6, 2010 at 5:57 PM, Joris Meys jorism...@gmail.com

Re: [R] T-test for loop

2010-05-06 Thread Greg Snow
-project.org; level Subject: Re: [R] T-test for loop Hehe, those homeworks. If you can explain this code to the professor, you surely passed. n -1 obs.rej.rate - sum(sapply(1:n,function(x){t.test(rnorm(10, 0.1, 1),alternative=greater,mu=0,conf.level=0.95)$p.value 0.05}))/n

Re: [R] T-test for loop

2010-05-06 Thread Joris Meys
[mailto:r-help-boun...@r- project.org] On Behalf Of Joris Meys Sent: Thursday, May 06, 2010 9:57 AM To: Dimitri Liakhovitski Cc: r-help@r-project.org; level Subject: Re: [R] T-test for loop Hehe, those homeworks. If you can explain this code to the professor, you surely passed. n

Re: [R] T-test for loop

2010-05-06 Thread David Winsemius
...@imail.org 801.408.8111 -Original Message- From: r-help-boun...@r-project.org [mailto:r-help-boun...@r- project.org] On Behalf Of Joris Meys Sent: Thursday, May 06, 2010 9:57 AM To: Dimitri Liakhovitski Cc: r-help@r-project.org; level Subject: Re: [R] T-test for loop Hehe, those homeworks

Re: [R] T-test for loop

2010-05-06 Thread David Winsemius
Intermountain Healthcare greg.s...@imail.org 801.408.8111 -Original Message- From: r-help-boun...@r-project.org [mailto:r-help-boun...@r- project.org] On Behalf Of Joris Meys Sent: Thursday, May 06, 2010 9:57 AM To: Dimitri Liakhovitski Cc: r-help@r-project.org; level Subject: Re: [R] T

[R] T-test for loop

2010-05-05 Thread level
I have been set a question which i understand statistically but my inability with R is preventing me from finishing it.. My question is that we to calculate the frequency of Type 1 errors starting with x = rnorm(10, 0.1, 1) then doing a t-test seeing whether you reject the null hypothesis

[R] t-test

2009-11-12 Thread amor Gandhi
Dear all, Is there any bayesian t-test in R? Many thanks, Gandhi __ z gegen Massenmails. [[alternative HTML version deleted]] __ R-help@r-project.org mailing list

Re: [R] T-test to check equality, unable to interpret the results.

2009-09-18 Thread Greg Snow
...@imail.org 801.408.8111 -Original Message- From: r-help-boun...@r-project.org [mailto:r-help-boun...@r- project.org] On Behalf Of Robert Hall Sent: Wednesday, September 16, 2009 12:55 PM To: r-help Subject: [R] T-test to check equality, unable to interpret the results. Hi, I have

Re: [R] T-test to check equality, unable to interpret the results.

2009-09-18 Thread Greg Snow
-Original Message- From: r-help-boun...@r-project.org [mailto:r-help-boun...@r- project.org] On Behalf Of Rolf Turner Sent: Wednesday, September 16, 2009 2:31 PM To: Bert Gunter Cc: 'r-help' Subject: Re: [R] T-test to check equality, unable to interpret the results. On 17/09/2009, at 8:06 AM

[R] T-test to check equality, unable to interpret the results.

2009-09-16 Thread Robert Hall
Hi, I have the precision values of a system on two different data sets. The snippets of these results are as shown: sample1: (total 194 samples) 0.600238 0.800119 0.600238 0.200030 0.600238 ... ... sample2: (total 188 samples) 0.8001 0.2000 0.8001 0.

Re: [R] T-test to check equality, unable to interpret the results.

2009-09-16 Thread Erik Iverson
, Erik Iverson -Original Message- From: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org] On Behalf Of Robert Hall Sent: Wednesday, September 16, 2009 1:55 PM To: r-help Subject: [R] T-test to check equality, unable to interpret the results. Hi, I have the precision values

Re: [R] T-test to check equality, unable to interpret the results.

2009-09-16 Thread Steve Lianoglou
Hi, I was just going to send this when I saw Erik's post. He's right -- we can't say anything about your data, but we can say something about using a t-test. I'm not a real statistician, so this answer isn't very rigorous, but might be helpful. On Sep 16, 2009, at 2:55 PM, Robert Hall

Re: [R] T-test to check equality, unable to interpret the results.

2009-09-16 Thread Bert Gunter
Biostatistics -Original Message- From: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org] On Behalf Of Steve Lianoglou Sent: Wednesday, September 16, 2009 12:19 PM To: Robert Hall Cc: r-help Subject: Re: [R] T-test to check equality, unable to interpret the results. Hi, I

Re: [R] T-test to check equality, unable to interpret the results.

2009-09-16 Thread Rolf Turner
On 17/09/2009, at 8:06 AM, Bert Gunter wrote: snip Furthermore, the null can be other than equality -- e.g. that the mean of the first population is less than the second. snip QUIBBLE: Some elementary texts will indeed state the null hypothesis as ``mu_1 = mu_2'' when

[R] T-test to check equality, unable to interpret the results.

2009-09-16 Thread Robert Hall
Hi, I have the precision values of a system on two different data sets. The snippets of these results are as shown: sample1: (total 194 samples) 0.600238 0.800119 0.600238 0.200030 0.600238 ... ... sample2: (total 188 samples) 0.8001 0.2000 0.8001 0.

Re: [R] T-test to check equality, unable to interpret the results.

2009-09-16 Thread Steve Lianoglou
Hi Bert, On Sep 16, 2009, at 4:06 PM, Bert Gunter wrote: snip Finally, statistically different is a meaningless phrase. I'm not sure if you're quoting that to point out something in particular you're taking exception to, but I never said that. I did mention statistical significance with

[R] t-test, survey data

2009-03-11 Thread Marie Vandresse
*How can I do a t-test with survey data?* Thanks. Marie -- - Le Bureau fédéral du Plan fête ses 50 ans en 2009. Het Federaal Planbureau viert zijn 50-ste verjaardag in 2009. The Federal Planning Bureau

Re: [R] t-test, survey data

2009-03-11 Thread Thomas Lumley
On Wed, 11 Mar 2009, Marie Vandresse wrote: *How can I do a t-test with survey data?* The 'survey' package does analysis of survey data. There isn't a t-test function; the easiest way to test for differences in means is with a linear regression model, using svyglm() -thomas

Re: [R] T-test by groups

2009-02-26 Thread Uwe Ligges
Ingrid Tohver wrote: I would like to run a t-test within a by group function. My dataset, error, is organized as the following (I have 133 Sites): Site week Dataset Region lat_map long_map mean_tsim diff20 diff40 diff80 ALFI 15 USACE UC 48.15625 -117.0938 8.87 1.34

Re: [R] T-test by groups

2009-02-26 Thread Peter Dalgaard
Uwe Ligges wrote: Ingrid Tohver wrote: I would like to run a t-test within a by group function. My dataset, error, is organized as the following (I have 133 Sites): Site week Dataset Region lat_map long_map mean_tsim diff20 diff40 diff80 ALFI 15 USACE UC 48.15625 -117.0938

[R] T-test by groups

2009-02-25 Thread Ingrid Tohver
I would like to run a t-test within a by group function. My dataset, error, is organized as the following (I have 133 Sites): Site week Dataset Region lat_map long_map mean_tsim diff20 diff40 diff80 ALFI 15 USACE UC 48.15625 -117.0938 8.87 1.34 1.90 2.98 ALFI 16

[R] t-test

2009-01-29 Thread Amit Patel
When doing the t-test in the below manner will r compare each element of the array with the relevant one. I.e. if i was comparing x and y would (1 and 0) and (1 and 9) be treated as separate variables. Or does it just assume one variable. # test data x - c(1,1.1,1.15,1.2,1.21,1.23) y -

Re: [R] t-test

2009-01-29 Thread patricia garcía gonzález
are not taken into account. Regards Patricia Date: Thu, 29 Jan 2009 13:59:41 + From: amitrh...@yahoo.co.uk To: r-help@r-project.org Subject: [R] t-test When doing the t-test in the below manner will r compare each element of the array with the relevant one. I.e. if i was comparing x

[R] t-test between percentages

2008-09-17 Thread Bunny, lautloscrew.com
Hi all, though i know this is a simple question, i really hope someone could. I am just trying to compare percents respectively the difference in percents by a simple test. t.test usually compares means and is working like it is supposed to be. Now i wonder how i can use a test in R to

Re: [R] t-test between percentages

2008-09-17 Thread Bert Gunter
Of Bunny, lautloscrew.com Sent: Wednesday, September 17, 2008 9:41 AM To: r-help@r-project.org Subject: [R] t-test between percentages Hi all, though i know this is a simple question, i really hope someone could. I am just trying to compare percents respectively the difference in percents by a simple

Re: [R] t-test between percentages

2008-09-17 Thread David Winsemius
On Sep 17, 2008, at 12:41 PM, Bunny, lautloscrew.com wrote: Hi all, though i know this is a simple question, i really hope someone could. I am just trying to compare percents respectively the difference in percents by a simple test. t.test usually compares means and is working like it is

[R] T-test

2008-08-11 Thread Angelo Scozzarella
Hi, How can I make a t-test if I haven't got all data set but I know the numbers of subjects for each group, the mean and di standard deviation for each group? Thanks Angelo Scozzarella __ R-help@r-project.org mailing list

Re: [R] T Test

2008-08-11 Thread Erik Iverson
Just plug your values into the t-test formula, you don't need R for this, you can use a calculator. If you want a p-value then use the pt() function in R after getting the t statistic. Angelo Scozzarella wrote: Hi, I want to calculate the T-Test from means and sd. How can I do it? Thanks

[R] T-Test Help

2008-08-11 Thread Angelo Scozzarella
Hi, I want to calculate the T-Test from means and sd. How can I do it? Thanks Angelo Scozzarella __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide

Re: [R] T-Test Help

2008-08-11 Thread Bill.Venables
Sent: Tuesday, 12 August 2008 2:59 PM To: r-help@r-project.org Subject: [R] T-Test Help Hi, I want to calculate the T-Test from means and sd. How can I do it? Thanks Angelo Scozzarella __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman

Re: [R] t-test for multiple variables

2008-07-19 Thread Simon Anders
Hi Henning, Henning Wildhagen wrote: i tried your code, but it results in an error: error in var(x) : `x` is empty Do you have an idea what the reason might be? If you ask questions on this list, please provide some code snippets, which the others can copy and paste to reproduce your error.

[R] t-test for multiple variables

2008-07-18 Thread Henning Wildhagen
Dear list, i try to do my first statistics with R. Given a dataframe of three columns, where col1 is of type factor, col 2 and col3 are numeric and pairs of observations i would like to perform a paired t-test for each level of col1. I would like to avoid specifying the levels of col1 manually

Re: [R] t-test for multiple variables

2008-07-18 Thread Simon Anders
Hi Henning, Henning Wildhagen wrote: Given a dataframe of three columns, where col1 is of type factor, col 2 and col3 are numeric and pairs of observations i would like to perform a paired t-test for each level of col1. I would like to avoid specifying the levels of col1 manually because it

Re: [R] t-test for multiple variables

2008-07-18 Thread Henning Wildhagen
] An: Henning Wildhagen [EMAIL PROTECTED] CC: r-help@r-project.org Betreff: Re: [R] t-test for multiple variables Hi Henning, Henning Wildhagen wrote: Given a dataframe of three columns, where col1 is of type factor, col 2 and col3 are numeric and pairs of observations i would