t-test single

Projekt_1/T-student-single.R

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+t.test_single <- function(x, m, alternative = "two.sided") {
+  M <- mean(x)
+  n <- length(x)
+  statistic <- ((M - m) / sd(x)) * sqrt(n)
+  
+  p <- if (alternative == "two.sided") {
+    2 * pt(q=abs(statistic), df=length(x)-1, lower.tail=FALSE)
+  } else if (alternative == "less") {
+    pt(q=statistic, df=length(x)-1, lower.tail = TRUE)
+  } else {
+    pt(q=statistic, df=length(x)-1, lower.tail = FALSE)
+  }
+  
+  value <- list(mean = M, m = m, statistic = statistic, p.value = p,  alternative = alternative)
+  return(value)
+}
+
+
+load("Hamulce.RData")
+attach(Hamulce)
+t.test(Wynik,mu=18.6,alternative='less')
+t.test_single(Wynik, m=18.6, alternative='less')
+
+
+
+

Projekt_1/T-studnet-multiple.R

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+t.test_knownvar <- function(x, y, V1, V2, m0 = 0, alpha = 0.05, alternative = "two.sided") {
+  M1 <- mean(x)
+  M2 <- mean(y)
+  n1 <- length(x)
+  n2 <- length(y)
+  sigma1 <- sqrt(V1)
+  sigma2 <- sqrt(V2)
+  S <- sqrt((V1 / n1) + (V2 / n2))
+  statistic <- (M1 - M2 - m0) / S
+  p <- if (alternative == "two.sided") {
+    2 * pnorm(abs(statistic), lower.tail = FALSE)
+  } else if (alternative == "less") {
+    pnorm(statistic, lower.tail = TRUE)
+  } else {
+    pnorm(statistic, lower.tail = FALSE)
+  }
+  LCL <- (M1 - M2 - S * qnorm(1 - alpha / 2))
+  UCL <- (M1 - M2 + S * qnorm(1 - alpha / 2))
+  value <- list(mean1 = M1, mean2 = M2, m0 = m0, sigma1 = sigma1, sigma2 = sigma2, S = S, statistic = statistic, p.value = p, LCL = LCL, UCL = UCL, alternative = alternative)
+  # print(sprintf("P-value = %g",p))
+  # print(sprintf("Lower %.2f%% Confidence Limit = %g",
+  #               alpha, LCL))
+  # print(sprintf("Upper %.2f%% Confidence Limit = %g",
+  #               alpha, UCL))
+  return(value)
+}