search for: hypothesis

...'' values for SSA and/or SSB ***and*** a significant value for the interaction sum of squares, SSAB. Point 2 --- What does such ``significance'' ***mean***? It is not correct to say that it means nothing at all. The significance of say, SSA, reports on the result of the test of a hypothesis. This hypothesis is a ***meaningful*** hypothesis. It may well not be an important hypothesis, or a particularly interesting hypothesis, or a hypothesis that the experimenter actually cares about. It is substantially different from the hypothesis which is tested by SSA when there is no interaction...

...ADF regression with systemfit and obtained the same coefficient estimates as through ADF.test (as it had to be). Unfortunately I could not find how to extract AIC from the result of systemfit, so I evaluated the ADF regression by lm. So far so good. However the results of ftest.systemfit and linear.hypothesis from the "car" package are very different, while the results from waldtest.systemfit and linear.hypothesis coincide. I have no explanation for this issue a nd I could not see the code of linear.hypothesis. When I type "linear.hypothesis" I get: function (model, ...) UseMethod(...

Hi, I had a question about specifying the Null hypothesis in a significance test. Advance apologies if this has already been asked previously or is a naive question. I have two samples A and B, and I want to test whether A and B come from the same distribution. The default Null hypothesis would be H0: A=B But since I am trying to prove that A and B indee...

...ing ks.test for a standard exponential distribution on samples of dimension 2500, generated everytime as new, i had this strange behaviour: >data<-rexp(2500,0.4) >ks.test(data,"pexp",0.4) One-sample Kolmogorov-Smirnov test data: data D = 0.0147, p-value = 0.6549 alternative hypothesis: two.sided >data<-rexp(2500,0.4) >ks.test(data,"pexp",0.4) One-sample Kolmogorov-Smirnov test data: data D = 0.019, p-value = 0.3305 alternative hypothesis: two.sided >data<-rexp(2500,0.4) >ks.test(data,"pexp",0.4) One-sample Kolmogorov-Smirnov test da...

Dear all, For analysis of a longitudinal data set with fixed measurement in time I built a gls model (nlme). For testing hypotheses in this model I used the linear.hypothesis function from the car package. A check with the results obtained in SAS proc MIXED with a repeated statement revealed an inconsistency in the results. The problem can be that the linear.hypothesis function (1) only gives the asymptotic chi square test and/or (2) only uses the residual error. Is the...

Dear R developers, Currently many (all?) test functions in R describe the alternative hypothesis, but not the the null hypothesis being tested. For example, cor.test: > require(boot) > data(mtcars) > with(mtcars, cor.test(mpg, wt, met="kendall")) Kendall's rank correlation tau data: mpg and wt z = -5.7981, p-value = 0.000000006706 alternative hypothesis: true tau is...

Dear R users, I am analyzing several response variables (all scaled to [0;1]) using a multivariate linear model. After fitting the model, I set up a hypothesis matrix to test specific contrasts for these response variables; for example: "a always increases significantly more than b when regressed against x". What I am stuck with now is how to calculate the correct F-values (and against how many d.f. to test them) after calling linear.hypothesis...

...on of a paired t-test. (i don't think that this matters, but I'm using R 2.10.1 on Windows). to my questions: i've been using a lot of time about this minor concerns now and I hope you can help me... I use one- and two-sided t-tests. My questons are on one side about how R uses the hypothesis' and the second one is about p-vaues. First the one-sided: > t.test(var1,var2,paired=T,alternative="g") Paired t-test data: var1 and var2 t = 4.3456, df = 50, p-value = 3.401e-05 alternative hypothesis: true difference in means is greater than 0 95 percent confidence...

...lcox.test(a, b, alternative="l", mu=0, exact=FALSE, paired=FALSE) #2nd wilcox.test(a, b, alternative="g", mu=0, exact=FALSE, paired=FALSE) #3rd ... and it's returning: Wilcoxon rank sum test with continuity correction data: a and b W = 145, p-value = 0.08969 alternative hypothesis: true location shift is not equal to 0 Wilcoxon rank sum test with continuity correction data: a and b W = 145, p-value = 0.04485 alternative hypothesis: true location shift is less than 0 Wilcoxon rank sum test with continuity correction data: a and b W = 145, p-value = 0.9582 alternative hypo...

# Hi all: #I got a vector with fish lengths(mm) # Can someone help me interpret the output of # a t.test in plain english? # Based on the t.test below I can say that # I reject the null hypothesis because # the p-value is smaller than the the significance # level(alpha=0.05). What else can I conclude here? Ho = 36 mm Ha <> 36 mm fishlength <- c(35,32,37,39,42,45,37,36,35,34,40,42,41,50) t.test(fishlength,mu=36) One Sample t-test data: fishlength t...

Hi, I have been unable to find how to go about changing the significance level in R for hypothesis testing and regression analysis. R has a default setting to alpha=95% (a significance level of 95%), but I want to be able to decrease or increase this level when necessary. If you could give me instructions on how to change the significance level in R for hypothesis testing and regression analysis...

...given fairly large N, that should make little difference. Andy > From: Ross Clement > > Hi. I have a question that I have asked in other stat forums > but do not > yet have an answer for. I would like to know if there is some way in R > or otherwise of performing the following hypothesis test. > > I have a single data item x. The null hypothesis is that x > was selected > from a normal distribution N(mu,sigma). The alternate > hypothesis is that > x does not come from this distribution. > > However, I do not know the values of mu and sigma. I have a samp...

Hi, I hope to use R to perform some hypothesis testing, such as t.test() and var.test(). However, I don't find a function that could do test on means with variance known (i.e., u test or z test in some textbook), and a function that could do test on variances of normal distribution (i.e. chi-squared test). Thanks in advance for any hints...

Dear all If I run the model and get the estimated parameter a11. Then I want to use the estimated parameter to calculate the elasticities by using the formula e11=a11/mw1-1. What I have done is using the command of linear. Hypothesis. > formulas1=dWfresh~dlnPfresh+dlnPfrozen+dlnPsmoke+dlnQP+cosL1+sinL1+cosL2 > formulas2=dWsmoke~dlnPfresh+dlnPfrozen+dlnPsmoke+dlnQP+cosL1+sinL1+cosL2 > formulas12=list(formulas1,formulas2) > > salmon1=systemfit(formulas12, data=Fsalmon2, method="SUR") > summary...

Hi There, Using t.test to test hypothesis about which one is greater, A or B? where A={10,20,30},B={25,30,15}. My question is which of the following conclusions is right? #################hypothesis testing 1 h0: A greater than or equal to B h1: A less than B below is splus code A=c(10,20,30) B=c(25,30,15) t.test(c(10,20,30),c(25,30,15...

Dear colleague: Actually that is what is done. When using the z-test between proportions in two different groups, or using chi-squared to test the null hypothesis of equal proportions of two or more groups, the null hypothesis is that H0: p1=p2=p3.....=p where this p is the pooled proportion, the proportion in the summed groups = n1+n2+n3+..../N1+N2+N3.... in the z-test between two proportions, p1 and p2 are put in the numerator (p1-p2) while the poole...

...eetings, I'm rather new to R, and only just subscribed to the mailing list. I have run into a strange result in a t-test. The data represents the the hypothetical differences obtained for a t-test for dependent samples. All the numeric output looks OK, but the statement that the alternative hypothesis is accepted seems rather strange. > data <- c(-6,6,-4,11,6,-3,-12,7,-1,4) > length(data) > t.test (data,mu=0) One Sample t-test data: data t = 0.3548, df = 9, p-value = 0.7309 alternative hypothesis: true mean is not equal to 0 95 percent confidence interval: -4.300873...

...m not much used to use statistics. So, please forgive me if this is a FAQ or stupid, but I failed to find the answer by myself. I have used "runs.test" (Package tseries) for computes the runs test for randomness , but I get this result: Runs test -1.8732 P-value = 0.0610 Alternative Hypothesis : Two sided How can I interpret this result ? Generally, one rejects the null hypothesis if the p-value is smaller than or equal to the significance level,but I have examined the documentation but I don't find the significance level. Thanks in advance. -- Web Page http://geocities.com/lord_...

Hello, I have a MANOVA model and I want to test the following hypothesis: LBM = 0 where B is the parameter estimates. Is there any function to do this in R? Cheers, Philippe -- Philippe Hup? Institut Curie, CNRS UMR 144, INSERM U900 26 rue d'Ulm 75005 Paris - France Email : Philippe.Hupe at curie.fr T?l : +33 (0)1 56 24 69 91 Fax: +33 (0)1 56 24 69 11...

Hello, everyone! I would like to know how to calculate the F-value and P-value for a non-linear regression: y ~ a * X^b * W^c ? Note: a, b and c are coefficients of adjustment of the equation and X and W are variables previously measured ... Someone would have any suggestions? Thanks ... [[alternative HTML version deleted]]