t.test001 - waseda2bun_r @ ウィキ

 

#参考：tanaka2008,p198 #ho:true difference in means is 0 x <- rnorm(20,2.5,sd=sqrt(2));y <- rnorm(30,2,sd=sqrt(2)) t.test(x,y,alternative="greater",var.equal=TRUE) t.test(x,y,alternative="less",var.equal=TRUE)# ua<ub t.test(x,y,alternative="two.sided",var.equal=TRUE) # ua not equal ub x <- rnorm(10,2.5,sd=sqrt(2));y <- rnorm(10,2,sd=sqrt(2)) t.test(x,y,alternative="greater",var.equal=TRUE) t.test(x,y,alternative="less",var.equal=TRUE)# ua<ub t.test(x,y,alternative="two.sided",var.equal=TRUE) # ua not equal ub #ケース３ x <- rnorm(1000,2.5,sd=sqrt(2));y <- rnorm(1000,2.3,sd=sqrt(2)) t.test(x,y,alternative="greater",var.equal=TRUE) t.test(x,y,alternative="less",var.equal=TRUE)# ua<ub t.test(x,y,alternative="two.sided",var.equal=TRUE) # ua not equal ub

・ケース3についての結果

> x <- rnorm(1000,2.5,sd=sqrt(2));y <- rnorm(1000,2.3,sd=sqrt(2)) > t.test(x,y,alternative="greater",var.equal=TRUE)         Two Sample t-test（検定3-1） data:  x and y t = 4.5592, df = 1998, p-value = 2.723e-06 alternative hypothesis: true difference in means is greater than 0 95 percent confidence interval:  0.1794863       Inf sample estimates: mean of x mean of y  2.558959  2.278096 > t.test(x,y,alternative="less",var.equal=TRUE)# ua<ub         Two Sample t-test（検定3-2） data:  x and y t = 4.5592, df = 1998, p-value = 1 alternative hypothesis: true difference in means is less than 0 95 percent confidence interval:       -Inf 0.3822390 sample estimates: mean of x mean of y  2.558959  2.278096 > t.test(x,y,alternative="two.sided",var.equal=TRUE) # ua not equal ub         Two Sample t-test（検定3-3） data:  x and y t = 4.5592, df = 1998, p-value = 5.446e-06 alternative hypothesis: true difference in means is not equal to 0 95 percent confidence interval:  0.1600481 0.4016772 sample estimates: mean of x mean of y  2.558959  2.278096

・p.valueで比較 （検定3-1） 2.723e-06 <0.05より5%で棄却可能。   ・p.valueで比較 （検定3-2） 1＞0.05より5%で棄却できない。 ・p.valueで比較 （検定3-1） 5.446e-06 <0.05より5%で棄却可能。

 

#母平均の検定 #case01-1 x <- rnorm(20,20,2) t.test(x,mu=19,alternative="greater",var.equal=TRUE) t.test(x,mu=19,alternative="less",var.equal=TRUE)# ua<ub t.test(x,mu=19,alternative="two.sided",var.equal=TRUE) # ua not equal ub #case01-2 x <- rnorm(20,20,1) t.test(x,mu=19,alternative="greater",var.equal=TRUE) t.test(x,mu=19,alternative="less",var.equal=TRUE)# ua<ub t.test(x,mu=19,alternative="two.sided",var.equal=TRUE) # ua not equal ub #case02-1 x <- rnorm(200,20,2) t.test(x,mu=19,alternative="greater",var.equal=TRUE) t.test(x,mu=19,alternative="less",var.equal=TRUE)# ua<ub t.test(x,mu=19,alternative="two.sided",var.equal=TRUE) # ua not equal ub #case02-2 x <- rnorm(200,20,1) t.test(x,mu=19,alternative="greater",var.equal=TRUE) t.test(x,mu=19,alternative="less",var.equal=TRUE)# ua<ub t.test(x,mu=19,alternative="two.sided",var.equal=TRUE) # ua not equal ub