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powerMediation 0.3.4 (2021-03-23)

powerMediation 0.3.2 (2020-04-07)

powerMediation 0.3.1

powerMediation 0.3.0

powerMediation 0.2.9 (2018-02-07)

powerMediation 0.2.8 (2017-09-12)

the power calculation in sizePoisson() is for two-sided test

one-sided tests

powerMediation 0.2.7 (2017-02-16)

documentaion for the 'powerLongFull', 'ssLongFull' function

powerMediation 0.2.6 (2017-01-27)

So in version 0.2.6, 'rho2.mx' is dropped from the input list

powerMediation 0.2.5

as 'sigma.e

Dear Weiliang

one other question:

in the documentation for minEffect.SLR you require sigma.y as the input, but you fail to define it.

Is it the conditional variance of y given x? If so, why not call it sigma.e so as to avoid confusion

Same for other functions related to SLR

Thanks,

Answer:

Dear George

sigma.y is the marginal standard deviation of y, sd(y), not the conditional sd sd(y|x). Please find the attached reference paper Dupont and Plummer 1998.

I will revise the definition of sigma.y in the next release of powerMediation. Thanks for pointing out this ambiguity!

Best regards

Weiliang

powerMediation 0.2.4 (2015-05-08)

powerMediation 0.2.1

powerMediation 0.2.0

and 'SSizeLogisticCon.Rd' is not correct. The followings are his e-mail

on Jan 2, 2015. Based on Dr. ToRe Wentzel-Larsen's suggestion, I added one

phase '\eqn{\log(OR)} is the change in log odds for an increase of one unit in \eqn{X}.' to the interpretation of OR

Dear Weiliang Qiu

The formula in the documentation for this function is the same as formula (1) in the cited article by Hsieh et. al. (with beta^star written as log of the OR) However, in formula (1) in the article beta^star is not simply a regression coefficient under the alternative hypothesis, but a standardized effect size, see e. g. Appendix 1 and the Example in the article. This means that the OR has to be stated per a one standard deviation difference in the continuous independent variable in question. Perhaps that could be explicitly stated in the documentation for powerLogisticCon, since if not some users may erroneously use powerLogisticCon with the OR per one unit difference of the independent variable (although it is fairly obvious that some standardization is needed in powerLogisticCon, if not the computed power will differ as to whether the independent variable is measured in e. g. USD or 1000 USD).

Best regards, ToRe Wentzel-Larsen

powerMediation 0.1.9

powerMediation 0.1.8

powerMediation 0.1.7 (2013-11-09)

powerMediation 0.1.6

powerMediation 0.1.5

powerMediation 0.1.4

This is a typo in the file 'http://personal.health.usf.edu/ywu/logistic.pdf

regression, and logistic regression

powerMediation 0.1.3 (2013-04-29)

powerMediation 0.1.2

upload it again to CRAN

powerMediation 0.1.1

powerMediation 0.1.0 (2012-11-30)

powerMediation 0.0.9

powerMediation 0.0.8 (2012-03-12)

Dear Weiliang

your help file for deriving the power of the Soble test allows

users to enter sigma.m, sigma.x, theta.1a, and sigma.e as free

parameters. However

sigma.m^2 = theta.1a^2*sigma.x^2+sigma.e^2

so that sigma.m is not a free parameter. Indeed, in the example

given in your documentation, it appears that

sigma.m = sqrt( .1701^2*.57^2+.20^2) = 0.22

which conflicts with the 0.612 value assigned to this parameter

I belive that you should not have sigma.m as an argument to this

function

Further, the documentation refers to sigma.m, sigma.x as variances

whereas your code suggests they are standard deviations

Also, you refer to sigma.theta and sigma.lambda as standard deviations

whereas the formulae given suggest that they are variances

powerMediation 0.0.7 (2011-08-17)