Differences

This shows you the differences between two versions of the page.

--- r:two_sample_t-test [2026/04/05 23:57] – created hkimscil
+++ r:two_sample_t-test [2026/04/06 03:38] (current) – hkimscil
@@ Line 219: / Line 219: @@
 table(mdiffs < -4 | mdiffs > 4)
+</code>
-# repeated measure = to be deleted
-sz <- 50
-t5 <- rnorm2(sz, 75, 10)
-t6 <- rnorm2(sz, 82, 10)
-t.test(t5, t6, paired=T)
-diff <- t5-t6
-sd.diff <- sd(diff)
-se.diff <- sd.diff/sqrt(sz)
-m.diff <- mean(diff)
-t.cal <- m.diff/se.diff
-p.val <- pt(abs(t.cal), df=sz-1, lower.tail = F)*2
-df <- sz-1
-t.cal
-df
-p.val
-m.diff
-se.diff
-two <- qt(.05/2, df=sz-1)
-two
-lo2 <- se.diff*two
-lo2
-m.diff + lo2
-m.diff - lo2
-</code>
 <tabbox ro.two.sample.t-test>
 <code>
@@ Line 556: / Line 528: @@
     49
 >
-> # repeated measure = to be deleted
-> sz <- 50
-> t5 <- rnorm2(sz, 75, 10)
-> t6 <- rnorm2(sz, 82, 10)
->
-> t.test(t5, t6, paired=T)
-	Paired t-test
-data:  t5 and t6
-t = -3.3984, df = 49, p-value = 0.001355
-alternative hypothesis: true mean difference is not equal to 0
-percent confidence interval:
- -11.13931  -2.86069
-sample estimates:
-mean difference
-             -7
->
-> diff <- t5-t6
-> sd.diff <- sd(diff)
-> se.diff <- sd.diff/sqrt(sz)
-> m.diff <- mean(diff)
->
-> t.cal <- m.diff/se.diff
-> p.val <- pt(abs(t.cal), df=sz-1, lower.tail = F)*2
-> df <- sz-1
->
-> t.cal
-[1] -3.398399
-> df
-[1] 49
-> p.val
-[1] 0.001354538
->
-> m.diff
-[1] -7
-> se.diff
-[1] 2.059793
-> two <- qt(.05/2, df=sz-1)
-> two
-[1] -2.009575
-> lo2 <- se.diff*two
-> lo2
-[1] -4.13931
-> m.diff + lo2
-[1] -11.13931
-> m.diff - lo2
-[1] -2.86069
->
 </code>
 </tabbox>
 {{.:pasted:20260405-235733.png}}
 {{.:pasted:20260405-235744.png}}