{"id":1806,"date":"2019-06-10T00:02:14","date_gmt":"2019-06-09T15:02:14","guid":{"rendered":"http:\/\/141.164.34.82\/?p=1806"},"modified":"2019-06-10T00:28:19","modified_gmt":"2019-06-09T15:28:19","slug":"%ec%84%a0%ed%98%95-%eb%aa%a8%ed%98%95-1-%ec%84%a0%ed%98%95%ec%9d%98-%ec%9d%98%eb%af%b8","status":"publish","type":"post","link":"http:\/\/ds.sumeun.org\/?p=1806","title":{"rendered":"\uc120\ud615 \ubaa8\ud615 1: \uc120\ud615\uc758 \uc758\ubbf8"},"content":{"rendered":"

\ub4e4\uc5b4\uac00\uae30<\/h2>\n

\ubaa8\ub4e0 \ub370\uc774\ud130 \ubd84\uc11d\uc758 \uae30\ucd08\ub77c\uace0 \ud560 \uc218 \uc788\ub294 \uc120\ud615\ud68c\uadc0\ubd84\uc11d\uc740 \ub2e4\uc74c\uacfc \uac19\uc740 \ubaa8\ud615\uc744 \uae30\ucd08\ub85c \ubd84\uc11d\uc744 \ud569\ub2c8\ub2e4.<\/p>\n

\\[\\mathbb{E}[y|x_1, x_2, \\cdots, x_p] = \\beta_0 + \\beta_1 x_1 + \\beta_2 x_2 + \\cdots \\beta_p x_p\\]<\/p>\n

\ub9cc\uc57d \\(\\beta_0, \\beta_1, \\cdots \\beta_p\\) \uac00 \uc8fc\uc5b4\uc84c\ub2e4\uba74 \uc124\uba85\ubcc0\uc218 \\(x_1, x_2, \\cdots x_p\\) \ub85c \uacb0\uacfc\ubcc0\uc218 \\(y\\) \uc758 \ud3c9\uade0\uc744 \uc608\uce21\ud560 \uc218 \uc788\uc2b5\ub2c8\ub2e4. <\/p>\n

\uc880 \ub354 \uce5c\uadfc\ud55c \uc608\ub97c \ub4e4\uc5b4\ubd05\uc2dc\ub2e4. \ud0a4\uc640 \uc131\ubcc4\uc744 \ud1b5\ud574 \uccb4\uc911\uc744 \uc608\uce21\ud558\uace0\uc790 \ud560 \ub54c, \uc120\ud615\ud68c\uadc0\ubd84\uc11d\uc740 \ub2e4\uc74c\uc758 \ubaa8\ud615\uc744 \uae30\ucd08\ub85c \ud55c\ub2e4. <\/p>\n

\\[\\mathbb{E}[\\textrm{weight}|\\textrm{height}, \\textrm{gender}] = \\beta_0 + \\beta_1 \\textrm{height} + \\beta_2 \\textrm{gender}\\]<\/p>\n

\ub9cc\uc57d \\(\\beta_0=-80, \\beta_1=0.8, \\beta_2=10\\) \uc774\ub77c\uba74, \uc120\ud615\ud68c\uadc0\uc2dd\uc740 \\(\\mathbb{E}[\\textrm{weight}|\\textrm{height}, \\textrm{gender}] = -80 + 0.8 \\times \\textrm{height} + 10\\times \\textrm{gender}\\) \uc774 \ub41c\ub2e4. \ub9cc\uc57d \ud0a4(hegiht)\uac00 180, \uc131\ubcc4 \ub0a8\uc790(gender=1)\uc77c \ub54c, \ud0a4\ub294 \ud3c9\uade0 \\(\\mathbb{E}[\\textrm{weight}|\\textrm{weight}=180, \\textrm{gender}=1]= -80 + 0.8 \\times 180 + 10\\times 1 = 74\\) \ub85c \uc608\uce21\ub41c\ub2e4. \ud68c\uadc0\ubd84\uc11d\uc740 \uc790\ub8cc\ub97c \ud1b5\ud574 \\(\\beta_0, \\beta_1, \\beta_2\\) \ub97c \ucd94\uc815\ud558\uac8c \ub41c\ub2e4.<\/p>\n

carData<\/code> \ud328\ud0a4\uc9c0\uc758 Davis<\/code>\uc5d0\ub294 \ub0a8\/\ub140(sex<\/code>)\uc758 \ud0a4(height<\/code>)\uc640 \uccb4\uc911(weight<\/code>) \ub370\uc774\ud130\uac00 \ub4e4\uc5b4 \uc788\ub2e4. \uc774\uc5d0 \ub300\ud574 \uc704\uc758 \ubaa8\ud615\uc73c\ub85c \ud68c\uadc0\ubd84\uc11d\uc744 \ud574\ubcf8\ub2e4\uba74 \ub2e4\uc74c\uacfc \uac19\ub2e4.<\/p>\n

library(dplyr)\ndata(Davis, package='carData')\nDavis %>% filter(height > 100) -> Davis2\nlm(weight ~ height + sex, data=Davis2)\n<\/code><\/pre>\n
## \n## Call:\n## lm(formula = weight ~ height + sex, data = Davis2)\n## \n## Coefficients:\n## (Intercept)       height         sexM  \n##    -76.6362       0.8107       8.2162\n<\/pre>\n
Davis2 %>% mutate(sex = forcats::fct_relevel(sex, "M")) %>% \n  ggplot(aes(x=height, y=weight, col=sex)) + geom_point(alpha=0.7) + \n  #geom_smooth(method='lm')+\n  scale_color_discrete_diverging(palette='Blue-Red 3')\n<\/code><\/pre>\n
\"plot<\/p>\n
\uacb0\uacfc\ub97c \ubcf4\uba74 \\(\\hat{\\beta_0}=-76.6362\\), \\(\\hat{\\beta_1}=0.8107\\), \\(\\hat{\\beta_2}=8.2162\\) \uc774\ub2e4. \\(\\hat{}\\) \uc740 \uc790\ub8cc\ub97c \ud1b5\ud574 \ucd94\uc815<\/strong>\ub41c \uac12\uc784\uc744 \ub098\ud0c0\ub0b8\ub2e4.<\/p>\n
\uc120\ud615<\/strong>\ud68c\uadc0 \ubd84\uc11d\uc758 \uc120\ud615<\/strong><\/h2>\n
\ubaa8\ud615 \\(\\mathbb{E}[y|x_1, x_2, \\cdots, x_p] = \\beta_0 + \\beta_1 x_1 + \\beta_2 x_2 + \\cdots \\beta_p x_p\\) \uc5d0\uc11c \uc790\ub8cc\ub97c \ud1b5\ud574 \ucd94\uc815\ud574\uc57c\ud558\ub294 \\(\\beta_0, \\beta_1, \\cdots, \\beta_p\\) \ub97c \ubaa8\uc218 \ub610\ub294 \ud30c\ub77c\uba54\ud130(parameter)\ub77c\uace0 \ud55c\ub2e4. \uc120\ud615\ud68c\uadc0\ubd84\uc11d\uc5d0\uc11c \uc120\ud615<\/strong>\uc740 \ud68c\uadc0\uc2dd\uc774 \ubaa8\uc218\uc758 \uc120\ud615<\/strong> \ud568\uc218\uc784\uc744 \uc758\ubbf8\ud55c\ub2e4.<\/p>\n
\uc608\ub97c \ub4e4\uc5b4 \\(f(x_1) = \\beta_0 + \\beta_1 x_1 + \\beta_2 x_1^2\\) \uc740 \\(\\beta_0, \\beta_1, \\beta_2\\) \uc758 \uc120\ud615 \ud568\uc218\uc785\ub2c8\ub2e4. \ubc18\uba74 \\(f(x_1) = \\beta_0 + \\beta_1(x_1 + \\beta_2 )^2\\) \uc758 \uacbd\uc6b0\ub294 \\(\\beta_0, \\beta_1\\cdot\\beta_2, \\beta\\cdot\\beta_2^2\\) \ub4f1\uc744 \ud3ec\ud568\ud558\uace0 \uc788\uae30 \ub54c\ubb38\uc5d0 \\(\\beta_0, \\beta_1, \\beta_2\\) \uc758 \uc120\ud615 \ud568\uc218\uac00 \uc544\ub2d9\ub2c8\ub2e4. <\/p>\n
\ub450 \ud568\uc218\ub294 \ubaa8\ub450 \uac19\uc740 \ud615\ud0dc( \\(x_1\\) \uc758 \uc774\ucc28\ud568\uc218)\uc774\uc9c0\ub9cc \ud558\ub098\ub294 \uacc4\uc218\uc758 \uc120\ud615 \ud568\uc218[1]\uc774\uace0,<\/sup> \ub2e4\ub978 \ud558\ub098\ub294 \uadf8\ub807\uc9c0 \uc54a\ub2e4\ub294 \uc810\uc5d0 \uc8fc\ubaa9\ud558\uae38 \ubc14\ub78d\ub2c8\ub2e4.<\/p>\n
[1]:<\/sup> \uc120\ud615 \ubaa8\ud615 \\(\\mathbb{E}[y | x_1] = \\beta_0 + \\beta_1 x_1\\) \uc5d0\uc11c \\(\\beta_0, \\beta_1\\) \uc740 \uc120\ud615\ubaa8\ud615\uc758 \ubaa8\uc218<\/strong>\ub77c\uace0\ub3c4 \ud558\uace0, \uc808\ud3b8(intercept)<\/strong>\uacfc \\(x_1\\) \uc758 \uacc4\uc218(coefficient)<\/strong>\ub77c\uace0\ub3c4 \ud569\ub2c8\ub2e4. <\/p>\n
\uc120\ud615 \ubaa8\ud615\uc758 \uc7a5\uc810<\/h2>\n
\uc120\ud615 \ubaa8\ud615\uc740 \uacc4\uc218\uc758 \ucd94\uc815\uc774 \ub2e4\ub978 \ubaa8\ud615\ubcf4\ub2e4 \uc27d\uace0 \ube60\ub974\ub2e4\ub294 \uc7a5\uc810\uc774 \uc788\uc2b5\ub2c8\ub2e4.<\/p>\n
\uc77c\ubc18\uc801\uc73c\ub85c \\(\\mathbb{E}[y|x_1, x_2, \\cdots, x_p] = \\beta_0 + \\beta_1 x_1 + \\beta_2 x_2 + \\cdots \\beta_p x_p\\) \uc758 \uacc4\uc218\ub97c \ucd94\uc815\ud558\ub294 \uc2dd\uc740 \ub2e4\uc74c\uacfc \uac19\uc2b5\ub2c8\ub2e4.<\/p>\n
\ub9cc\uc57d \\(i\\)-\ubc88\uc9f8 \uad00\uce21\uac12\uc744 \\(x_{i1}, x_{i2}, \\cdots, x_{ip}, y_i\\) \ub77c\uace0 \ub193\uc73c\uba74, \uc704\uc758 \uc2dd\uc740 \ub2e4\uc74c\uacfc \uac19\uc774 \uc4f8 \uc218 \uc788\uc2b5\ub2c8\ub2e4.<\/p>\n
\\[y_i = \\beta_0 + \\beta_1 x_{i1} + \\beta_2 x_{i2} + \\cdots \\beta_p x_{ip} + e_i, \\ \\ e_i \\sim \\mathcal{N}(0, \\sigma^2)\\]<\/p>\n
\\(i\\) -\ubc88\uc9f8 \uad00\uce21\uac12\uacfc \\(k\\) -\ubc88\uc9f8 \uc608\uce21 \ubcc0\uc218\ub294 \\(x_{ik}\\) \ub85c \ub098\ud0c0\ub0b4\uc5c8\uc2b5\ub2c8\ub2e4. \ub9cc\uc57d \ub450 \ubcc0\uc218 \\(i\\) , \\(k\\) \uac00 \ubaa8\ub450 \uc544\ub7ab\ucca8\uc790\ub85c \ub418\uc5b4 \uc788\uc5b4 \ud5f7\uac08\ub9b0\ub2e4\uba74 \\(x_i^{(k)}\\) \ub85c \uc4f8 \uc218\ub3c4 \uc788\uc2b5\ub2c8\ub2e4. \uadf8\ub807\uac8c \ud45c\uae30\ud558\uba74 \uc704\uc758 \uc2dd\uc740 \ub2e4\uc74c\uacfc \uac19\uc774 \uc4f8 \uc218 \uc788\uc2b5\ub2c8\ub2e4. <\/p>\n
\\[y^{(i)} = \\beta_0 + \\beta_1 x_{1}^{(i)} + \\beta_2 x_{2}^{(i)} + \\cdots \\beta_p x_{p}^{(i)} + e^{(i)}, \\ \\ e^{(i)} \\sim \\mathcal{N}(0, \\sigma^2)\\]<\/p>\n
\ucc38\uace0\ub85c \\(\\mathcal{N}(0, \\sigma^2)\\) \ub294 \uc624\ucc28\ud56d \\(e^{(i)}\\) \uac00 \ubaa8\ub450 \ud3c9\uade0 \\(0\\) , \ubd84\uc0b0 \\(\\sigma^2\\) \uc758 \uc815\uaddc\ubd84\ud3ec\ub97c \ub530\ub974\uace0 \uc788\uc74c\uc744 \ub098\ud0c0\ub0c5\ub2c8\ub2e4.<\/p>\n
\uc704\uc758 \uc2dd\uc5d0\uc11c \uc624\ucc28\ud56d\uc744 \uc81c\uc678\ud55c \\(y^{(i)}\\) \uc758 \ucd94\uc815\uac12\uc740 \\(\\beta_0 + \\beta_1 x_{1}^{(i)} + \\beta_2 x_{2}^{(i)} + \\cdots \\beta_p x_{p}^{(i)}\\) \uc774\uace0, \ubaa8\ub4e0 \uad00\ucc30\uac12\uc5d0 \ub300\ud574 \uc774 \uac12\uc744 \uad6c\ud574\uc11c \uc5f4\ubca1\ud130\ub85c \ub9cc\ub4e4\uc5b4 \ubcf8\ub2e4\uba74 \ub2e4\uc74c\uacfc \uac19\uc2b5\ub2c8\ub2e4.<\/p>\n
\"\"\/<\/p>\n
\uc5ec\uae30\uc11c \uc6b0\ubcc0\uc740 \ud589\ub82c\uc758 \uacf1\uc148\uc73c\ub85c \ub2e4\uc74c\uacfc \uac19\uc774 \ub098\ud0c0\ub0bc \uc218 \uc788\uc2b5\ub2c8\ub2e4. <\/p>\n
\"\"\/<\/p>\n
\uc774\ub4e4\uc744 \uac04\ub2e8\ud558\uac8c \ud589\ub82c \\(\\mathbf{X}\\) \uc640 \uc5f4 \ubca1\ud130 \\(\\vec{\\beta}\\) \ub85c \uc4f0\uaca0\uc2b5\ub2c8\ub2e4. \\(\\mathbf{X}\\) \ub294 \uc790\ub8cc\ub85c \uc8fc\uc5b4\uc9c4 \ubd80\ubd84(\uc608\uce21 \ubcc0\uc218)\uc774\uace0, \uc6b0\ub9ac\uac00 \ucd94\uc815\ud574\uc57c \ud560 \ubaa8\uc218(\ud30c\ub77c\uba54\ud130)\ub294 \\(\\vec{\\beta}\\) \uc785\ub2c8\ub2e4.<\/p>\n
\"\"\/<\/p>\n
\uadf8\ub9ac\uace0 \uacb0\uacfc \ubcc0\uc218 \\(y^{(i)}\\) \ub97c \ubaa8\ub450 \ubaa8\uc544 \\(\\vec{y}\\) \uc73c\ub85c \ub098\ud0c0\ub0c5\ub2c8\ub2e4.<\/p>\n
\\(i\\) -\ubc88\uc9f8 \uc624\ucc28 \\(e^{(i)}\\) \ub3c4 \ubaa8\ub450 \ubaa8\uc544 \\(\\vec{e}\\) \ub85c \ud45c\uae30\ud558\uba74 \ub2e4\uc74c\uc774 \uc131\ub9bd\ud569\ub2c8\ub2e4.<\/p>\n
\\[\\vec{e} = \\vec{y} – \\mathbf{X} \\vec{\\beta}\\]<\/p>\n
\uc5ec\uae30\uc11c \uc624\ucc28\uc640 \\(\\vec{\\beta}\\) \ub294 \uc6b0\ub9ac\uac00 \uc720\ud55c\uac1c\uc758 \uad00\ucc30\uac12\uc73c\ub85c \uc815\ud655\ud558\uac8c \uc54c \uc218 \uc5c6\ub294 \uac12\uc785\ub2c8\ub2e4. <\/p>\n
\\(\\vec{\\beta}\\) \ub97c \ucd94\uc815\ud558\ub294 \ud55c \uac00\uc9c0 \ubc29\ubc95\uc740 \uc624\ucc28\ub4e4\uc740 \uc624\ucc28\uc81c\uacf1\ud569(SSE; S<\/strong>um of S<\/strong>quares E<\/strong>rror)\uc744 \ucd5c\uc18c\ud654\ud558\ub294 \ubaa8\uc218\ub97c \uad6c\ud558\ub294 \uac83\uc785\ub2c8\ub2e4.<\/p>\n
\uc624\ucc28\uc81c\uacf1\ud569\uc740 \ub2e4\uc74c\uacfc \uac19\uc774 \ub098\ud0c0\ub0bc \uc218 \uc788\uc2b5\ub2c8\ub2e4.<\/p>\n
\\[\\hat{\\vec{e}}^T \\hat{\\vec{e}} = (\\vec{y} – \\mathbf{X} \\hat{\\vec{\\beta})}^T (\\vec{y} – \\mathbf{X} \\hat{\\vec{\\beta})}\\]<\/p>\n
\\((\\vec{y} – \\mathbf{X} \\hat{\\vec{\\beta})}^T (\\vec{y} – \\mathbf{X} \\hat{\\vec{\\beta}})\\) \uc5d0\uc11c \\(\\vec{y}\\) \uc640 \\(\\mathbf{X}\\) \ub294 \ubaa8\ub450 \uc790\ub8cc\uc5d0\uc11c \uc8fc\uc5b4\uc9c4 \uac12\ub4e4\ub85c \uad6c\uc131\ub418\uace0, \uc6b0\ub9ac\uac00 \ubaa8\ub974\ub294 \uac12\uc740 \\(\\hat{\\vec{\\beta}}\\) \uc785\ub2c8\ub2e4. \\(\\hat{\\vec{\\beta}}\\) \uc5d0 \uc11c\ub85c \ub2e4\ub978 \uac12\uc744 \ub300\uc785\ud568\uc5d0 \ub530\ub77c \uc624\ucc28\uc81c\uacf1\ud569\uc758 \ud06c\uae30\ub3c4 \ub2e4\ub974\uac8c \ucd94\uc815\ub418\ub294 \ub370, (\ucd94\uc815) \uc624\ucc28\uc81c\uacf1\ud569\uc758 \ud06c\uae30\ub97c \ucd5c\uc18c\ub85c\ud558\ub294 \\(\\hat{\\vec{\\beta}}\\) \ub85c \\(\\vec{\\beta}\\) \ub97c \ucd94\uc815\ud558\ub294 \uac83\uc774 \ud754\ud788 \ub9d0\ud558\ub294 \ucd5c\uc18c\uc81c\uacf1\ubc95<\/strong>(method of least squares)\uc785\ub2c8\ub2e4. <\/p>\n
\ud589\ub82c\uc744 \ud65c\uc6a9\ud55c \ucd5c\uc18c\uc81c\uacf1\ubc95\uc740 \ub2e4\uc74c \uc2dc\uac04\uc5d0 \uc124\uba85\ud558\uaca0\uc2b5\ub2c8\ub2e4. \uc5b4\uca0b\ub4e0 \uc120\ud615 \ubaa8\ud615\uc758 \uc7a5\uc810\uc740 \ubaa8\ub4e0 \ubaa8\ud615\uc744 \\(\\vec{y} = \\mathbf{X} \\vec{\\beta} + \\vec{e}\\) \ub85c \ub098\ud0c0\ub0bc \uc218 \uc788\uc73c\uba70, \\(\\vec{\\beta}\\) \ub97c \ucd5c\uc18c\uc81c\uacf1\ubc95\uc73c\ub85c \ucd94\uc815\ud558\ub294 \uc798 \uc54c\ub824\uc9c4 \ubc29\ubc95\uc774 \uc874\uc7ac\ud55c\ub2e4\ub294 \uac83\uc785\ub2c8\ub2e4. \uadf8\ub9ac\uace0 \ud589\ub82c\uc774\ub860\uc744 \ud1b5\ud574 \ucd5c\uc18c\uc81c\uacf1\ubc95\uc73c\ub85c \\(\\vec{\\beta}\\) \uc744 \uc720\uc77c\ud558\uac8c \ucd94\uc815\ud560 \uc218 \uc788\ub294 \uacbd\uc6b0\uc640 \uadf8\ub807\uc9c0 \uc54a\uc740 \uacbd\uc6b0 \ub4f1\ub3c4 \ud655\uc778\ud560 \uc218\ub3c4 \uc788\uc2b5\ub2c8\ub2e4. <\/p>\n
\\(\\mathbf{X}\\) \ub97c \uacb0\uc815\ud558\ub294 \ubc29\ubc95<\/h2>\n
\uc55e\uc5d0\uc11c \ubd24\ub4ef\uc774 \uc120\ud615 \ubaa8\ud615\uacfc \uc790\ub8cc\uac00 \uc8fc\uc5b4\uc9c0\uba74 \\(\\vec{y}\\) \uc640 \\(\\mathbf{X}\\) \uac00 \uacb0\uc815\ub429\ub2c8\ub2e4. \ud558\uc9c0\ub9cc \ud754\ud788 \ubaa8\ud615 \ud589\ub82c(model matrix)\ub85c \ubd88\ub9ac\ub294 \\(\\mathbf{X}\\) \ub97c \uacb0\uc815\ud558\ub294 \ubc29\ubc95\uc740 \uc5ec\ub7ec \uac00\uc9c0\uac00 \uc788\uc2b5\ub2c8\ub2e4.<\/p>\n
\uc55e\uc5d0\uc11c \ub4e4\uc5c8\ub358 \uc608\ub97c \ubd05\uc2dc\ub2e4.<\/p>\n
\\(f(x_1) = \\beta_0 + \\beta_1 x_1 + \\beta_2 x_1^2\\) \uacfc \\(f(x_1) = \\beta_0 + \\beta_1(x_1 + \\beta_2 )^2\\) \ub294 \ubaa8\ub450 \\(x_1\\) \uc758 \uc774\ucc28 \ud568\uc218\ub97c \ub098\ud0c0\ub0c5\ub2c8\ub2e4. <\/p>\n
\ub450 \ud568\uc218\ub97c \ub2e4\uc2dc \uc815\ub9ac\ud574\ubcf4\uba74 \ub2e4\uc74c\uacfc \uac19\uc2b5\ub2c8\ub2e4. <\/p>\n
\\[f(x_1) = \\beta_0 + \\beta_1 x_1 + \\beta_2 x_1^2\\]
\n\\[f(x_1) = (\\beta_0+\\beta_1\\beta_2^2) + (2\\beta_1 \\beta_2) x_1 + \\beta_1 x_1^2\\]<\/p>\n
\uacc4\uc218\uc758 \uc120\ud615 \ud568\uc218\uc5d0\uc11c\ub3c4 \ub3d9\uc77c\ud55c \ud568\uc218\ub97c \ub2e4\ub978 \ubc29\ubc95\uc73c\ub85c \ub098\ud0c0\ub0bc \uc218 \uc788\uc2b5\ub2c8\ub2e4. \ub2e4\uc74c\uc758 \uc608\ub97c \ubd05\uc2dc\ub2e4.<\/p>\n
\\[f(x_1, x_2) = \\beta_0 + \\beta_1 x_1 + \\beta_2 x_2\\]
\n\\[f(x_1, x_2) = \\beta_0 + \\beta_1 x_1 + \\beta_2 (x_2-x_1) = \\beta_0 + (\\beta_1 – \\beta_2) x_1 + \\beta_2 x_2\\]<\/p>\n
\ub450 \ud568\uc218 \ubaa8\ub450 \uac19\uc740 \ubaa8\ud615\uc744 \ub098\ud0c0\ub0bc \uc218 \uc788\uc2b5\ub2c8\ub2e4. \uc608\ub97c \ub4e4\uc5b4 \\(f(x1, x2) = 1-2 \\cdot x_1 + 1\\cdot x_2\\) \uc740 \\(1-1\\cdot x_1 + 1\\cdot(x_2-x_1)\\) \ub85c\ub3c4 \uc4f8 \uc218 \uc788\uc2b5\ub2c8\ub2e4.<\/p>\n
\uc774 \ubd80\ubd84\uc740 \ud2b9\ud788 \ubc94\uc8fc\ud615 \ubcc0\uc218\ub97c \ud3ec\ud568\ud558\ub294 \uc120\ud615 \ubaa8\ud615\uc5d0\uc11c \uc911\uc694\ud558\uac8c \ub429\ub2c8\ub2e4. <\/p>\n
\uc694\uc57d\/\uc815\ub9ac<\/h2>\n
    \n
  • \uc5ec\uae30\uc11c\ub294 \ud754\ud788 \ub9d0\ud558\ub294 \uc120\ud615<\/strong> \ubaa8\ud615(linear<\/strong> model)\uc5d0\uc11c \uc120\ud615<\/strong>\uc758 \uc758\ubbf8\ub97c \uc54c\uc544\ubcf4\uc558\uc2b5\ub2c8\ub2e4. \uadf8\ub9ac\uace0 \uc120\ud615 \ubaa8\ud615\uc744 \ud589\ub82c\uc2dd\uc73c\ub85c \ud45c\ud604\ud574\ubcf4\uc558\uc2b5\ub2c8\ub2e4. \ub2e4\uc74c\uc5d0\ub294 \ubaa8\ud615 \ud589\ub82c \\(\\mathbf{X}\\) \ub97c \uacb0\uc815\ud558\ub294 \uc11c\ub85c \ub2e4\ub978 \ubc29\ubc95\ub4e4\uc5d0 \ub300\ud574 \uc54c\uc544\ubcf4\uace0, \uc2e4\uc81c \uc120\ud615 \ubaa8\ud615\uc744 \ubd84\uc11d\ud558\ub294 R\uc758 \uba85\ub839\uc5b4(lm<\/code>; l<\/strong>inear m<\/strong>odel)\uc5d0\uc11c \ubaa8\ud615 \ud589\ub82c\uc744 \uacb0\uc815\ud558\ub294 \ubc29\ubc95\uc5d0 \ub300\ud574 \uc54c\uc544\ubcf4\uaca0\uc2b5\ub2c8\ub2e4.<\/li>\n<\/ul>\n\n
    [\ucc38\uace0] \uc120\ud615 \ud568\uc218<\/h4>\n
    \uc120\ud615<\/strong> \ud568\uc218\ub780 \uc785\ub825\uac12\uc758 \ubcc0\ud654\ub7c9\uc5d0 \ucd9c\ub825\uac12\uc758 \ubcc0\ud654\ub7c9\uc774 \ud56d\uc0c1 \ube44\ub840\ud558\ub294 \ud568\uc218\ub85c \ub2e4\uc74c\uacfc \uac19\uc740 \ud615\uc2dd\uc774\ub2e4. \uc608\ub97c \ub4e4\uc5b4 \uc5b4\ub5a4 \ud568\uc218 \\(f(x_1, x_2)\\) \uac00 \uc120\ud615 \ud568\uc218\ub77c\uba74 \ub2e4\uc74c\uc744 \ub9cc\uc871\ud55c\ub2e4.<\/p>\n
    \\[f(x_{11}, x_2)-f(x_{10},x_2) = \\alpha_1 (x_{11}-x_{10})\\]
    \n\\[f(x_1, x_{21})-f(x_1,x_{20}) = \\alpha_2 (x_{21}-x_{20})\\]
    \n\\(x_1\\) \uc774 \\(x_{10}\\) \uc5d0\uc11c \\(x_{11}\\) \uc73c\ub85c \ubcc0\ud560 \ub54c, \ud568\uc218 $f$\uc758 \ubcc0\ud654\ub7c9\uc740 \\((x_{11}-x_{10})\\), \uc989 $x_1$\uc758 \ubcc0\ud654\ub7c9\uc5d0 \ud56d\uc0c1<\/strong> \ube44\ub840\ud55c\ub2e4. \uadf8\ub9ac\uace0 $x_1$\uacfc $x_2$\uac00 \ubaa8\ub450 \uc774\ub7f0 \uc81c\uc57d\uc744 \ub9cc\uc871\ud558\ub294 \ud568\uc218\ub294 \ub2e4\uc74c\uc758 \ud615\ud0dc\ubc16\uc5d0 \uc5c6\ub2e4.<\/p>\n
    \\[f(x_1, x_2) = \\alpha_0 + \\alpha_1 x_1 + \\alpha_2 x_2\\]<\/p>\n
    \uc774 \ud568\uc218\ub294 $x_1$\uacfc \\(x_2\\) \uc758 \uc120\ud615 \ud568\uc218\uc774\ub2e4. \ubaa8\uc218 \\(\\beta_0\\), \\(\\beta_1\\) \uc758 \uc120\ud615\ud568\uc218\ub294 \ub2e4\uc74c\uacfc \uac19\uc740 \ud615\ud0dc\ub97c \ub748\ub2e4.<\/p>\n
    \\[f(\\beta_0, \\beta_1) = \\alpha_0 + \\alpha_1 \\beta_0  + \\alpha_2 \\beta_1\\]<\/p>\n","protected":false},"excerpt":{"rendered":"
    \ub4e4\uc5b4\uac00\uae30 \ubaa8\ub4e0 \ub370\uc774\ud130 \ubd84\uc11d\uc758 \uae30\ucd08\ub77c\uace0 \ud560 \uc218 \uc788\ub294 \uc120\ud615\ud68c\uadc0\ubd84\uc11d\uc740 \ub2e4\uc74c\uacfc \uac19\uc740 \ubaa8\ud615\uc744 \uae30\ucd08\ub85c \ubd84\uc11d\uc744 \ud569\ub2c8\ub2e4. \\[\\mathbb{E}[y|x_1, x_2, \\cdots, x_p] = \\beta_0 + \\beta_1 x_1 + \\beta_2 x_2 + \\cdots \\beta_p x_p\\] \ub9cc\uc57d \\(\\beta_0, \\beta_1, \\cdots \\beta_p\\) \uac00 \uc8fc\uc5b4\uc84c\ub2e4\uba74 \uc124\uba85\ubcc0\uc218 \\(x_1, x_2, \\cdots x_p\\) \ub85c \uacb0\uacfc\ubcc0\uc218 \\(y\\) \uc758 \ud3c9\uade0\uc744 \uc608\uce21\ud560 \uc218 \uc788\uc2b5\ub2c8\ub2e4. \uc880 \ub354 \uce5c\uadfc\ud55c \uc608\ub97c […]<\/p>\n","protected":false},"author":1,"featured_media":1816,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[28,319,320],"tags":[314,324,323,321,322,325,326],"jetpack_featured_media_url":"http:\/\/ds.sumeun.org\/wp-content\/uploads\/2019\/06\/lm_01_formula.png","_links":{"self":[{"href":"http:\/\/ds.sumeun.org\/index.php?rest_route=\/wp\/v2\/posts\/1806"}],"collection":[{"href":"http:\/\/ds.sumeun.org\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/ds.sumeun.org\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/ds.sumeun.org\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/ds.sumeun.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1806"}],"version-history":[{"count":8,"href":"http:\/\/ds.sumeun.org\/index.php?rest_route=\/wp\/v2\/posts\/1806\/revisions"}],"predecessor-version":[{"id":1818,"href":"http:\/\/ds.sumeun.org\/index.php?rest_route=\/wp\/v2\/posts\/1806\/revisions\/1818"}],"wp:featuredmedia":[{"embeddable":true,"href":"http:\/\/ds.sumeun.org\/index.php?rest_route=\/wp\/v2\/media\/1816"}],"wp:attachment":[{"href":"http:\/\/ds.sumeun.org\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1806"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/ds.sumeun.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1806"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/ds.sumeun.org\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1806"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}