CODEWITHSUNDEEP
rfunctionp-valuehypothesis-test
redwoods
redwoods

Reputation: 59

(Homework Question) alternative hypothesis argument

I apologize for the vague title, but I don't really know to explain it well cause I just don't understand what it is I'm supposed to do.

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Below is my code which I believe provides everything e (ii) asks for, but I don't know what to do for the alt = "two-sided" argument. Any help in clarifying it would be appreciated and please let me know if what I have is wrong

ev <- function(x, mu0 = y, lev = 0.95) {
  ts<- ((mean(x)-mu0)/(sd(x)/sqrt(length(x))))
  pval <- 2*pnorm(-abs(ts))
  ci<- mean(x) + qt(lev / 2, length(x) - 1) * sd(x) / sqrt(length(x)) * c(-1, 1)
    return(list(c(ts,pval, ci)))
}
s<- rnorm(20)
> ev(s,0.2)
[[1]]
[1] -0.65345075  0.51346573  0.10089696  0.07954784


ev <- function(x, mu0 = y, alt = "two-sided", lev = 0.95) {
  ts<- ((mean(x)-mu0)/(sd(x)/sqrt(length(x))))
  if(alt == "two-sided") {
    pval <- 2*pnorm(-abs(ts))
  ci<- c((mu0- pval*(length(x)/ts)), mu0 + pval*(length(x)/ts))
  }
  else if(alt == "greater"){
    pval <- (1- pnorm(-abs(ts)))
    ci<- c((mu0- pval*(length(x)/ts)), mu0 + pval*(length(x)/ts))
  }
  else if(alt == "less") {
    pval <- pnorm(-abs(ts))
    ci<- c((mu0- pval*(length(x)/ts)), mu0 + pval*(length(x)/ts))
  }
    return(list(c(ts,pval, ci)))
}

Upvotes: 2

Views: 83

Answers (1)

Dubukay
Dubukay

Reputation: 2071

From comments:

Use if/else statements to handle the different alternative hypotheses because they are fundamentally different tests with different priors, so they'll have different p-values and confidence intervals.

if(alt == "two-sided") {
    # Do the thing
  } else if(alt == "greater"){
    # Do the other thing
  } else if(alt == "less") {
    # Do the third thing
  } else {
    stop('"alt" must be one of "two-sided", "greater", "less"'
  }

Upvotes: 1

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