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visits member for 1 year, 9 months
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1h
comment strucchange problem with csv files
Any issues have likely arisen by not defining the data you read in as a time series - see ?ts.
1d
comment R lme4 1.1-7: REML=FALSE giving error “extra argument(s) ‘REML’ disregarded ”
@Patrick: On the face of it, but there's an underlying statistical question: How do you (does it make sense to) fit a non-Gaussian generalized linear mixed model using restricted maximum likelihood? IMO it'd be better to address that in the answers rather than close the question.
1d
reviewed Approve suggested edit on How to test for a home bias in a data set?
1d
reviewed Leave Open R lme4 1.1-7: REML=FALSE giving error “extra argument(s) ‘REML’ disregarded ”
1d
reviewed Leave Open Has anyone publicly shared an implementation of RUSBoost in R?
1d
answered Do you know of any public circular/angular dataset?
1d
comment Mann Whitney test with unequal variances
... implications that one might think; in practice I then look at histograms or whatever to see what's going on.
1d
comment Mann Whitney test with unequal variances
@ttnphns: It tests, in general, whether the probability that an observation from one population is greater than an observation from the other population differs from one half. If you assume the cdfs don't cross that implies stochastic dominance of one over the other. It's often a reasonable assumption - a poison, say, retards the growth of some seedlings more than others, but doesn't advance that of any - & can be informally checked by examining the empirical cdfs. Without that assumption, you can say, well, the probability that an observation &c., but that statement doesn't have all the ...
1d
comment Mann Whitney test with unequal variances
@ttnphns: Yes - stochastic dominance of $X$ over $Y$ means $\Pr(X>a) \geq \Pr(Y>a)$ for all $a$ (& of course $\Pr(X>a) > \Pr(Y>a)$ for some $a$). Note also that stochastic dominance of $X$ over $Y$ together with stochastic dominance of $Y$ over $Z$ implies stochastic dominance of $X$ over $Z$, whereas $\Pr(X>Y)>\frac{1}{2}$ together with $\Pr(Y>Z)>\frac{1}{2}$ doesn't imply $\Pr(X>Z)>\frac{1}{2}$; dice illustrating the latter situation make nice Xmas presents.
1d
revised ANOVA on binomial data
fixed typos
1d
comment ANOVA on binomial data
(+1) ... if all groups have the same no. observations.
2d
comment Mann Whitney test with unequal variances
@ttnphns: To test for stochastic dominance you do have to assume the cumulative distribution functions don't cross. Else you're just testing whether the probability that an observation from one population is greater than an observation from the other population differs from one half.
2d
comment A priori justification for using a quartic regression
Casio calculators have a QUARTREG but no QUINTREG function. But four seems like it would be a reasonable number of degrees of freedom to use in empirically modelling a non-linear relationship between predictor & response in many situations - allowing for a straightish curve, one with a single peak or trough, or one that flattens off, quite comfortably - so @Glen_b's probably right.
2d
revised False alarm in Neyman-Pearson Test. A doubt in text?
fixed typo
2d
reviewed Approve suggested edit on Significance of variance components in Stata output
Aug
26
reviewed Approve suggested edit on Is there a result showing a relation between the size of the residuals and the correlation coefficient?
Aug
26
reviewed Close based on the classifiers
Aug
26
reviewed Close polynomial regression model
Aug
26
reviewed Close How to handle large .csv file in R?
Aug
23
reviewed Close What is the meaning of empirical size and power?How to calculate them?