{"id":3430,"date":"2023-07-17T13:07:49","date_gmt":"2023-07-17T13:07:49","guid":{"rendered":"https:\/\/statorials.org\/cn\/r%e4%b8%ad%e7%9a%84%e4%b8%a4%e4%b8%aa%e6%a0%b7%e6%9c%act%e6%a3%80%e9%aa%8c\/"},"modified":"2023-07-17T13:07:49","modified_gmt":"2023-07-17T13:07:49","slug":"r%e4%b8%ad%e7%9a%84%e4%b8%a4%e4%b8%aa%e6%a0%b7%e6%9c%act%e6%a3%80%e9%aa%8c","status":"publish","type":"post","link":"https:\/\/statorials.org\/cn\/r%e4%b8%ad%e7%9a%84%e4%b8%a4%e4%b8%aa%e6%a0%b7%e6%9c%act%e6%a3%80%e9%aa%8c\/","title":{"rendered":"\u5982\u4f55\u5728 r \u4e2d\u6267\u884c\u4e24\u4e2a\u6837\u672c t \u68c0\u9a8c"},"content":{"rendered":"

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\u53cc\u6837\u672c t \u68c0\u9a8c<\/a>\u7528\u4e8e\u68c0\u9a8c\u4e24\u4e2a\u603b\u4f53\u7684\u5747\u503c\u662f\u5426\u76f8\u7b49\u3002<\/span><\/p>\n

\u60a8\u53ef\u4ee5\u4f7f\u7528\u4ee5\u4e0b\u57fa\u672c\u8bed\u6cd5\u5728 R \u4e2d\u6267\u884c\u4e24\u4e2a\u793a\u4f8b t \u68c0\u9a8c\uff1a<\/span><\/p>\n

 t. test<\/span> (group1, group2, var. equal<\/span> = TRUE<\/span> ) \n<\/strong><\/pre>\n
\u6ce8\u610f<\/strong>\uff1a\u901a\u8fc7\u6307\u5b9avar.equal=TRUE<\/strong> \uff0c\u6211\u4eec\u544a\u8bc9 R \u5047\u8bbe\u4e24\u4e2a\u6837\u672c\u4e4b\u95f4\u7684\u65b9\u5dee\u76f8\u7b49\u3002<\/span><\/p>\n
\u4ee5\u4e0b\u793a\u4f8b\u5c55\u793a\u4e86\u5982\u4f55\u5728\u5b9e\u8df5\u4e2d\u5728 R \u4e2d\u6267\u884c\u4e24\u4e2a\u6837\u672c t \u68c0\u9a8c\u3002<\/span><\/p>\n
\u793a\u4f8b\uff1aR \u4e2d\u7684\u53cc\u6837\u672c T \u68c0\u9a8c<\/strong><\/span><\/h2>\n
\u5047\u8bbe\u6211\u4eec\u60f3\u77e5\u9053\u4e24\u79cd\u4e0d\u540c\u79cd\u7c7b\u7684\u690d\u7269\u662f\u5426\u5177\u6709\u76f8\u540c\u7684\u5e73\u5747\u9ad8\u5ea6\u3002<\/span><\/p>\n
\u4e3a\u4e86\u6d4b\u8bd5\u8fd9\u4e00\u70b9\uff0c\u6211\u4eec\u4ece\u6bcf\u4e2a\u7269\u79cd\u4e2d\u6536\u96c6\u4e86 12 \u79cd\u690d\u7269\u7684\u7b80\u5355\u968f\u673a\u6837\u672c<\/a>\u3002<\/span><\/p>\n
\u4ee5\u4e0b\u4ee3\u7801\u663e\u793a\u5982\u4f55\u5728 R \u4e2d\u6267\u884c\u4e24\u4e2a\u6837\u672c t \u68c0\u9a8c\u4ee5\u786e\u5b9a\u4e24\u4e2a\u7269\u79cd\u4e4b\u95f4\u7684\u5e73\u5747\u9ad8\u5ea6\u662f\u5426\u76f8\u7b49\uff1a<\/span><\/p>\n
 #create vectors to hold plant heights from each sample\n<\/span>group1 <- c(8, 8, 9, 9, 9, 11, 12, 13, 13, 14, 15, 19)\ngroup2 <- c(11, 12, 13, 13, 14, 14, 14, 15, 16, 18, 18, 19)\n\n<\/strong>#perform two sample t-tests\n<\/span>t. test<\/span> (group1, group2, var. equal<\/span> = TRUE<\/span> )\n\n\tTwo Sample t-test\n\ndata: group1 and group2\nt = -2.5505, df = 22, p-value = 0.01823\nalternative hypothesis: true difference in means is not equal to 0\n95 percent confidence interval:\n -5.5904820 -0.5761847\nsample estimates:\nmean of x mean of y \n 11.66667 14.75000 \n<\/strong><\/pre>\n
\u4ee5\u4e0b\u662f\u5982\u4f55\u89e3\u91ca\u6d4b\u8bd5\u7ed3\u679c\uff1a<\/span><\/p>\n
 data\uff1a<\/strong>\u5305\u542b\u6837\u672c\u6570\u636e\u7684\u5411\u91cf\u7684\u540d\u79f0\u3002<\/span><\/p>\n
 t\uff1a<\/strong> t \u68c0\u9a8c\u7edf\u8ba1\u91cf\u3002\u5728\u672c\u4f8b\u4e2d\u4e3a-2.5505<\/strong> \u3002<\/span><\/p>\n
 df<\/strong> \uff1a\u81ea\u7531\u5ea6\uff0c\u8ba1\u7b97\u516c\u5f0f\u4e3a n 1<\/sub> + n 2<\/sub> \u2013 2 = 12 + 12 \u2013 2 = 22<\/strong> \u3002<\/span><\/p>\n
 p \u503c\uff1a<\/strong>\u5bf9\u5e94\u4e8e -2.5505 \u548c df = 22 \u7684\u68c0\u9a8c\u7edf\u8ba1\u91cf\u7684 p \u503c\u3002p \u503c\u7ed3\u679c\u4e3a.01823<\/strong> \u3002\u6211\u4eec\u53ef\u4ee5\u4f7f\u7528T \u5206\u6570\u5230 P \u503c\u8ba1\u7b97\u5668<\/a>\u6765\u786e\u8ba4\u8be5\u503c\u3002<\/span><\/p>\n
 95% \u7f6e\u4fe1\u533a\u95f4\uff1a<\/strong>\u4e24\u7ec4\u4e4b\u95f4\u5e73\u5747\u503c\u771f\u5b9e\u5dee\u5f02\u7684 95% \u7f6e\u4fe1\u533a\u95f4\u3002\u7ed3\u679c\u662f[-5.59, -.576]<\/strong> \u3002<\/span><\/p>\n
\u6837\u672c\u4f30\u8ba1\uff1a<\/strong>\u6bcf\u7ec4\u7684\u6837\u672c\u5e73\u5747\u503c<\/a>\u3002\u5728\u672c\u4f8b\u4e2d\uff0c\u7b2c 1 \u7ec4\u7684\u6837\u672c\u5e73\u5747\u503c\u4e3a11.667<\/strong> \uff0c\u7b2c 2 \u7ec4\u7684\u6837\u672c\u5e73\u5747\u503c\u4e3a14.75<\/strong> \u3002<\/span><\/p>\n
\u6b64\u7279\u5b9a\u53cc\u6837\u672c t \u68c0\u9a8c\u7684\u539f\u5047\u8bbe\u548c\u5907\u62e9\u5047\u8bbe\u5982\u4e0b\uff1a<\/span><\/p>\n
 H 0<\/sub> :<\/strong> \u00b5 1<\/sub> = \u00b5 2<\/sub> \uff08\u4e24\u4e2a\u603b\u4f53\u5e73\u5747\u503c\u76f8\u7b49\uff09<\/span><\/p>\n
 H A<\/sub> :<\/strong> \u00b5 1<\/sub> \u2260 \u00b5 2<\/sub> \uff08\u4e24\u4e2a\u603b\u4f53\u5e73\u5747\u503c\u4e0d<\/em>\u76f8\u7b49\uff09<\/span><\/p>\n
\u6211\u4eec\u7684\u68c0\u9a8c\u7684 p \u503c(0.01823)<\/strong>\u5c0f\u4e8e 0.05\uff0c\u6211\u4eec\u62d2\u7edd\u539f\u5047\u8bbe\u3002<\/span><\/p>\n
\u8fd9\u610f\u5473\u7740\u6211\u4eec\u6709\u8db3\u591f\u7684\u8bc1\u636e\u5f97\u51fa\u7ed3\u8bba\uff0c\u4e24\u4e2a\u7269\u79cd\u4e4b\u95f4\u7684\u5e73\u5747\u682a\u9ad8\u4e0d\u76f8\u7b49\u3002<\/span><\/p>\n
\u6280\u672f<\/span>\u8bf4\u660e<\/span><\/strong><\/h2>\n
R \u4e2d\u7684t.test()<\/strong>\u51fd\u6570\u4f7f\u7528\u4ee5\u4e0b\u8bed\u6cd5\uff1a<\/span><\/p>\n
 t. test<\/span> (x, y, alternative=\"two.sided\", mu=0, paired=FALSE, var.equal=FALSE, conf.level=0.95)<\/span><\/strong><\/pre>\n
\u91d1\u5b50\uff1a<\/span><\/p>\n
\u5982\u679c\u60a8\u4e0d\u60f3\u505a\u51fa\u6b64\u5047\u8bbe\uff0c\u53ea\u9700\u5c06\u6b64\u53c2\u6570\u653e\u5728\u4e00\u8fb9\uff0cR \u5c06\u6539\u4e3a\u6267\u884cWelch t \u68c0\u9a8c<\/a>\uff0c\u8be5\u68c0\u9a8c\u4e0d\u5047\u8bbe\u6837\u672c\u4e4b\u95f4\u7684\u65b9\u5dee\u76f8\u7b49\u3002<\/span><\/p>\n