{"id":879,"date":"2019-01-29T21:28:48","date_gmt":"2019-01-29T12:28:48","guid":{"rendered":"http:\/\/141.164.34.82\/?p=879"},"modified":"2022-02-03T17:29:07","modified_gmt":"2022-02-03T08:29:07","slug":"operations-and-functions","status":"publish","type":"post","link":"http:\/\/ds.sumeun.org\/?p=879","title":{"rendered":"\uc5f0\uc0b0\uacfc \ud568\uc218(Operations and Functions)"},"content":{"rendered":"<h1>\uc5f0\uc0b0(Operations)\uacfc \ud568\uc218(Functions)<\/h1>\n<h3>\uc22b\uc790(<code>numeric<\/code>)<\/h3>\n<h4>\uc0b0\uc220\uc5f0\uc0b0(Arithmetic operations)<\/h4>\n<pre><code class=\"r\">3 + 2\r\n5 - 4\r\n3 * 2\r\n72 \/ 2\r\n3 ^ 4\r\n3 ** 4\r\n3 ^ (1\/2)\r\nsqrt(3)\r\n3 - 2 + 2 * 4 \/ 2 ^ (1 + 1)\r\n# PEMDAS(Parenthesize , Exponentiate , Multiply , Divide, Add, Subtract)\r\n7 \/ 3 # Float division\r\n7 %\/% 3 # Integer division\r\n7 %% 3 # Remainder\r\n<\/code><\/pre>\n<ul>\n<li>\uc0ac\uce59\uc5f0\uc0b0(<code>+<\/code>, <code>-<\/code>, <code>*<\/code>, <code>\/<\/code>)\uacfc \uc81c\uacf1(<code>^<\/code>, <code>**<\/code>)\uc740 \uac00\uc7a5 \uae30\ubcf8\uc801\uc778 \uc5f0\uc0b0\uc774\ub2e4. \uc774\ub4e4\uc774 \ud55c \uc2dd \uc548\uc5d0 \uc874\uc7ac\ud560 \uacbd\uc6b0 \uc5f0\uc0b0 \uc21c\uc11c\ub294 PEMDAS\ub85c \uc815\ud574\uc9c4\ub2e4. \uad04\ud638, \uc81c\uacf1, \uacf1\uc148\uacfc \ub098\ub217\uc148, \ub354\ud558\uae30\uc640 \ube7c\uae30 \uc21c\uc774\ub2e4.\n<ul>\n<li><strong>P<\/strong>arenthesize(\uad04\ud638)<\/li>\n<li><strong>E<\/strong>xponentiate(\uc81c\uacf1)<\/li>\n<li><strong>M<\/strong>ultiply\/<strong>D<\/strong>ivide(\uc2b9\uc81c)<\/li>\n<li><strong>A<\/strong>dd\/<strong>S<\/strong>ubstract(\uac00\uac10)<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<h4>\ud568\uc218<\/h4>\n<pre><code class=\"r\">exp(1)\r\n<\/code><\/pre>\n<pre>## [1] 2.718282\r\n<\/pre>\n<pre><code class=\"r\">log(180, base=2)\r\n<\/code><\/pre>\n<pre>## [1] 7.491853\r\n<\/pre>\n<pre><code class=\"r\">log2(180)\r\n<\/code><\/pre>\n<pre>## [1] 7.491853\r\n<\/pre>\n<pre><code class=\"r\">log10(180)\r\n<\/code><\/pre>\n<pre>## [1] 2.255273\r\n<\/pre>\n<pre><code class=\"r\">sin(2)\r\n<\/code><\/pre>\n<pre>## [1] 0.9092974\r\n<\/pre>\n<ul>\n<li>\uc704\uc758 \ucf54\ub4dc\ub294 \ub300\ud45c\uc801\uc778 \ucd08\uc6d4\ud568\uc218\ub97c R\uc5d0\uc11c \uad6c\ud55c \uac83\uc774\ub2e4.\n<ul>\n<li><code>log2(180)<\/code> = \\(\\log_2 180\\)<\/li>\n<li><code>log10(180)<\/code> = \\(\\log_{10} 180\\)<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<h4>\uc5f0\uc0b0<\/h4>\n<pre><code class=\"r\">\"+\"(3,2)\r\n<\/code><\/pre>\n<pre>## [1] 5\r\n<\/pre>\n<pre><code class=\"r\">\"*\"(3,2)\r\n<\/code><\/pre>\n<pre>## [1] 6\r\n<\/pre>\n<pre><code class=\"r\">\"%p%\" = function(x,y) { 2^x + y^2 }\r\n3 %p% 2\r\n<\/code><\/pre>\n<pre>## [1] 12\r\n<\/pre>\n<pre><code class=\"r\">\"%p%\"(3,2)\r\n<\/code><\/pre>\n<pre>## [1] 12\r\n<\/pre>\n<ul>\n<li>\ub4a4\uc5d0\uc11c \uc0b4\ud3b4\ubcf4\uaca0\uc9c0\ub9cc R\uc5d0\uc11c \ubaa8\ub4e0 \uc774\ud56d \uc5f0\uc0b0\uc740 \ubcf8\uc9c8\uc801\uc73c\ub85c \ud568\uc218\uc774\ub2e4. \ub2e4\uc74c\uc744 \ud55c \ubc88 \uc2e4\ud589\uc2dc\ucf1c\ubcf4\uc790.<\/li>\n<\/ul>\n<pre><code class=\"r\">\"+\" = function(x, y) x*y\r\n3+2\r\n<\/code><\/pre>\n<pre>## [1] 6\r\n<\/pre>\n<pre><code class=\"r\">3+3\r\n<\/code><\/pre>\n<pre>## [1] 9\r\n<\/pre>\n<pre><code class=\"r\">\"+\"\r\n<\/code><\/pre>\n<pre>## [1] \"+\"\r\n<\/pre>\n<ul>\n<li>\ub367\uc148\uc774 \uacf1\uc148\uc774 \ub418\uc5c8\ub2e4! \uc6d0\uc0c1\ud68c\ubcf5\ud558\ub824\uba74 <code>rm(\"+\")<\/code>.<\/li>\n<\/ul>\n<h4>\ube44\uad50 \uc5f0\uc0b0<\/h4>\n<pre><code class=\"r\">7 &lt; 3\r\n<\/code><\/pre>\n<pre>## [1] FALSE\r\n<\/pre>\n<pre><code class=\"r\">7 &gt; 3\r\n<\/code><\/pre>\n<pre>## [1] TRUE\r\n<\/pre>\n<pre><code class=\"r\">7 == 3\r\n<\/code><\/pre>\n<pre>## [1] FALSE\r\n<\/pre>\n<pre><code class=\"r\">7 != 3\r\n<\/code><\/pre>\n<pre>## [1] TRUE\r\n<\/pre>\n<pre><code class=\"r\">sqrt(2)^2 == 2\r\n<\/code><\/pre>\n<pre>## [1] FALSE\r\n<\/pre>\n<pre><code class=\"r\">print(sqrt(2)^2)\r\n<\/code><\/pre>\n<pre>## [1] 2\r\n<\/pre>\n<pre><code class=\"r\">print(sqrt(2)^2, digits = 21)\r\n<\/code><\/pre>\n<pre>## [1] 2.0000000000000004\r\n<\/pre>\n<pre><code class=\"r\">all.equal(sqrt(2)^2, 2)\r\n<\/code><\/pre>\n<pre>## [1] TRUE\r\n<\/pre>\n<pre><code class=\"r\">all.equal(1e-23, 1e-24)\r\n<\/code><\/pre>\n<pre>## [1] TRUE\r\n<\/pre>\n<ul>\n<li>R\uc5d0\uc11c \ub300\uc18c\uc640 \uac19\uc74c\uc744 \ud655\uc778\ud558\ub294 \uc5f0\uc0b0\uc740 <code>&lt;<\/code>, <code>&gt;<\/code>, <code>==<\/code>\uc774\ub2e4. \ucef4\ud4e8\ud130\uc758 \uc5f0\uc0b0\uacfc \uc218 \ud45c\ud604\uc740 \uc815\ud655\uc131\uc5d0 \ud55c\uacc4\uac00 \uc788\ub2e4. <code>all.equal<\/code>\uc740 \uc774\ub7f0 \ud55c\uacc4\ub97c \uace0\ub824\ud558\uc5ec \uc644\uc804\ud788 \ub3d9\uc77c\ud558\uc9c0 \uc54a\uc544\ub3c4 \ucda9\ubd84\ud788 \ube44\uc2b7\ud558\ub2e4\uba74 <code>TRUE<\/code>\ub97c \ubc18\ud658\ud55c\ub2e4. <code>dplyr<\/code> \ud328\ud0a4\uc9c0\uc758 <code>near<\/code> \ud568\uc218\ub3c4 \ube44\uc2b7\ud55c \uc5ed\ud560\uc744 \ud55c\ub2e4.<\/li>\n<\/ul>\n<pre><code class=\"r\">dplyr::near(1e-23, 1e-24)\r\n<\/code><\/pre>\n<pre>## [1] TRUE\r\n<\/pre>\n<pre><code class=\"r\">near &lt;- dplyr::near\r\nnear(1e-23, 1e-24)\r\n<\/code><\/pre>\n<pre>## [1] TRUE\r\n<\/pre>\n<h3>\ubb38\uc790(<code>character<\/code>)<\/h3>\n<pre><code class=\"r\">print(\"Letter\")\r\n<\/code><\/pre>\n<pre>## [1] \"Letter\"\r\n<\/pre>\n<pre><code class=\"r\">print('Letter')\r\n<\/code><\/pre>\n<pre>## [1] \"Letter\"\r\n<\/pre>\n<pre><code class=\"r\">print('\"Hello\", says he')\r\n<\/code><\/pre>\n<pre>## [1] \"\\\"Hello\\\", says he\"\r\n<\/pre>\n<pre><code class=\"r\">cat('\"Hello\", says he')\r\n<\/code><\/pre>\n<pre>## \"Hello\", says he\r\n<\/pre>\n<pre><code class=\"r\">print('Cheer up!\\r\\nRight Now!')\r\n<\/code><\/pre>\n<pre>## [1] \"Cheer up!\\r\\nRight Now!\"\r\n<\/pre>\n<pre><code class=\"r\">cat('Cheer up!\\r\\nRight Now!')\r\n<\/code><\/pre>\n<pre>## Cheer up!\r\n## Right Now!\r\n<\/pre>\n<pre><code class=\"r\">#https:\/\/stat.ethz.ch\/R-manual\/R-devel\/library\/base\/html\/Quotes.html\r\nnchar('hello?') # number of characters\r\n<\/code><\/pre>\n<pre>## [1] 6\r\n<\/pre>\n<pre><code class=\"r\">paste('Here is', 'an apple.')\r\n<\/code><\/pre>\n<pre>## [1] \"Here is an apple.\"\r\n<\/pre>\n<pre><code class=\"r\">substring('hello?', 2, 3) # from 2nd character to 3rd character\r\n<\/code><\/pre>\n<pre>## [1] \"el\"\r\n<\/pre>\n<ul>\n<li>\uc55e\uc5d0\uc11c \ubd24\ub4ef\uc774 <code>print<\/code>\uc640 <code>cat<\/code>\ub294 \ubb38\uc790\uc5f4\uc744 \ud654\uba74\uc5d0 \ud45c\uc2dc\ud560 \ub54c \uc4f0\uc778\ub2e4.<\/li>\n<li><code>nchar<\/code>\uc740 \ubb38\uc790\uc5f4\uc758 \ubb38\uc790 \uc218\ub97c \ubcf4\uc5ec\uc900\ub2e4.<\/li>\n<li><code>paste<\/code>\ub294 \ub450 \ubb38\uc790\uc5f4\uc744 \uc5f0\uacb0\ud560 \ub54c \uc4f0\uc778\ub2e4.<\/li>\n<li><code>substring<\/code>\uc740 \ubb38\uc790\uc5f4\uc758 \uc77c\ubd80\ubd84\uc744 \uc5bb\uc744 \ub54c \uc4f0\uc778\ub2e4.<\/li>\n<\/ul>\n<h3>\ub0a0\uc9dc\/\uc2dc\uac04(<code>Date<\/code>\/<code>POSIxct<\/code>)<\/h3>\n<pre><code class=\"r\">Sys.Date() # \ud604\uc7ac \ub0a0\uc9dc\r\n<\/code><\/pre>\n<pre>## [1] \"2019-03-13\"\r\n<\/pre>\n<pre><code class=\"r\">Sys.time() # \ud604\uc7ac \ub0a0\uc9dc\uc640 \uc2dc\uac04(POSIXct \ud615\uc2dd)\r\n<\/code><\/pre>\n<pre>## [1] \"2019-03-13 11:19:07 KST\"\r\n<\/pre>\n<pre><code class=\"r\">as.Date(\"2018\/12\/31\") # \ubb38\uc790\uc5f4 \"2018\/12\/31\"\uc744 \ub0a0\uc9dc \ud615\uc2dd\uc73c\ub85c\r\n<\/code><\/pre>\n<pre>## [1] \"2018-12-31\"\r\n<\/pre>\n<pre><code class=\"r\">as.POSIXct(\"2018\/12\/31 23:59:59\") \r\n<\/code><\/pre>\n<pre>## [1] \"2018-12-31 23:59:59 KST\"\r\n<\/pre>\n<pre><code class=\"r\"># \ubb38\uc790\uc5f4 \"2018\/12\/31 23:59:59\"\uc744 \ub0a0\uc9dc\uc2dc\uac04 \ud615\uc2dd\uc73c\ub85c\r\n\r\nSys.Date() - as.Date(\"2019-01-01\") # 2018\ub144 1\uc6d4 1\uc77c\uacfc \ud604\uc7ac \ub0a0\uc9dc\uc758 \ucc28\uc774\r\n<\/code><\/pre>\n<pre>## Time difference of 71 days\r\n<\/pre>\n<pre><code class=\"r\">as.POSIXct(\"2019\/12\/31 23:59:59\")-Sys.time()\r\n<\/code><\/pre>\n<pre>## Time difference of 293.5284 days\r\n<\/pre>\n<pre><code class=\"r\"># \ud604\uc7ac \ub0a0\uc9dc \uc2dc\uac04\uacfc 2019\ub144 12\uc6d4 31\uc77c 23\uc2dc 59\ubd84 59\ucd08\uc758 \ucc28\uc774\r\n\r\ndifftime(as.POSIXct(\"2018\/12\/31 23:59:59\"), Sys.time()) \r\n<\/code><\/pre>\n<pre>## Time difference of -71.47163 days\r\n<\/pre>\n<pre><code class=\"r\"># \ud604\uc7ac \ub0a0\uc9dc \uc2dc\uac04\uacfc 2018\ub144 12\uc6d4 31\uc77c 23\uc2dc 59\ubd84 59\ucd08\uc640\uc758 \ucc28\uc774\r\ndifftime(as.POSIXct(\"2018\/12\/31 23:59:59\"), Sys.time(), units='mins')\r\n<\/code><\/pre>\n<pre>## Time difference of -102919.1 mins\r\n<\/pre>\n<pre><code class=\"r\"># \ud604\uc7ac \ub0a0\uc9dc \uc2dc\uac04\uacfc 2018\ub144 12\uc6d4 31\uc77c 23\uc2dc 59\ubd84 59\ucd08\uc640\uc758 \ucc28\uc774(\ubd84 \ub2e8\uc704\ub85c)\r\ndifftime(as.POSIXct(\"2018\/12\/31 23:59:59\"), Sys.time(), units='secs')\r\n<\/code><\/pre>\n<pre>## Time difference of -6175149 secs\r\n<\/pre>\n<pre><code class=\"r\"># \ud604\uc7ac \ub0a0\uc9dc \uc2dc\uac04\uacfc 2018\ub144 12\uc6d4 31\uc77c 23\uc2dc 59\ubd84 59\ucd08\uc640\uc758 \ucc28\uc774(\ucd08 \ub2e8\uc704\ub85c)\r\n# units\uc740 \ub2e4\uc74c \uc911 \ud558\ub098: 'auto', 'secs', 'mins', 'hours', 'days', 'weeks'\r\n\r\nas.numeric(as.POSIXct(\"2018\/12\/31 23:59:59\"))-as.numeric(Sys.time())\r\n<\/code><\/pre>\n<pre>## [1] -6175149\r\n<\/pre>\n<pre><code class=\"r\"># POSIXct\ub294 \ucd08\ub2e8\uc704\ub85c \uc800\uc7a5\ub41c\ub2e4. \r\n(as.numeric(as.POSIXct(\"2018\/12\/31 23:59:59\"))-as.numeric(Sys.time()))\/60 \r\n<\/code><\/pre>\n<pre>## [1] -102919.1\r\n<\/pre>\n<pre><code class=\"r\"># \ucd08\ub97c 60\uc73c\ub85c \ub098\ub204\uba74 \ubd84 \ub2e8\uc704\uac00 \ub41c\ub2e4.\r\n<\/code><\/pre>\n<ul>\n<li><code>Sys.Date()<\/code>\uc740 \ud604\uc7ac \ub0a0\uc9dc, <code>Sys.time()<\/code>\uc740 \ud604\uc7ac \uc2dc\uac04\uc744 \ubcf4\uc5ec\uc900\ub2e4. <code>Sys.Date()<\/code>\uc758 <code>D<\/code>\ub294 \ub300\ubb38\uc790\uc774\uace0, <code>Sys.time()<\/code>\uc758 <code>t<\/code>\ub294 \uc18c\ubb38\uc790\uc784\uc744 \uc720\uc758\ud558\uc790.<\/li>\n<li><code>as.Date()<\/code>\uc640 <code>as.POSIXct<\/code>\ub294 \ub0a0\uc9dc \ub610\ub294 \ub0a0\ucc0c-\uc2dc\uac04\uc744 \ub098\ud0c0\ub0b4\ub294 \ubb38\uc790\uc5f4\uc744 \ub0a0\uc9dc, \ub0a0\uc9dc-\uc2dc\uac04 \ud615\uc2dd\uc758 R \ub370\uc774\ud130\ub85c \ubcc0\ud658\ud55c\ub2e4.\n<ul>\n<li>\ubb38\uc790\uc5f4\uacfc \ub0a0\uc9dc \ud615\uc2dd\uc758 \ub370\uc774\ud130\ub97c \ube44\uad50\ud574\ubcf4\uc790. \uc608\ub97c \ub4e4\uc5b4 \ubb38\uc790\uc5f4 <code>'2020-01-01'<\/code>\uacfc <code>'2019-12-31'<\/code>\uc744 \uc0dd\uac01\ud574\ubcf4\uc790. \uccab\ubc88\uc9f8 \ubb38\uc790\uc5f4\uc5d0\uc11c \ub450\ubc88\uc9f8 \ubb38\uc790\uc5f4\uc744 \ube7c\uc11c \ud558\ub8e8\ub97c \uc5bb\uc744 \uc218 \uc5c6\ub2e4. \uc65c\ub0d0\ud558\uba74 \ubb38\uc790\uc5f4\uc5d0\uc11c\ub294 <code>-<\/code> \uc5f0\uc0b0\uc774 \uc815\uc758\ub418\uc5b4 \uc788\uc9c0 \uc54a\uae30 \ub54c\ubb38\uc774\ub2e4.<\/li>\n<li>\ubc18\uba74 \ub0a0\uc9dc\ub294 <code>2020-01-01<\/code>\uc5d0\uc11c <code>2019-12-31<\/code>\uc744 \ube84 \uc218 \uc788\ub2e4.<\/li>\n<\/ul>\n<\/li>\n<li>\ub0a0\uc9dc \ub610\ub294 \ub0a0\uc9dc-\uc2dc\uac04 \ub370\uc774\ud130\uc5d0 \uad00\ud574 \uc790\uc138\ud55c \ub0b4\uc6a9\uc740 ???\uc7a5\uc5d0\uc11c \ub2e4\ub904\uc9c4\ub2e4.<\/li>\n<\/ul>\n<pre><code class=\"r\">'2020-01-01'-'2019-12-31'\r\n<\/code><\/pre>\n<pre>## Error in \"2020-01-01\" - \"2019-12-31\": non-numeric argument to binary operator\r\n<\/pre>\n<pre><code class=\"r\">as.Date('2020-01-01')-as.Date('2019-12-31')\r\n<\/code><\/pre>\n<pre>## Time difference of 1 days\r\n<\/pre>\n<h3>\ub17c\ub9ac(<code>logical<\/code>)<\/h3>\n<pre><code class=\"r\">(7 &lt; 3) &amp; (4 &gt; 3)\r\n<\/code><\/pre>\n<pre>## [1] FALSE\r\n<\/pre>\n<pre><code class=\"r\">(7 &lt; 3) | (4 &gt; 3)\r\n<\/code><\/pre>\n<pre>## [1] TRUE\r\n<\/pre>\n<pre><code class=\"r\">!(7 &lt; 3)\r\n<\/code><\/pre>\n<pre>## [1] TRUE\r\n<\/pre>\n<pre><code class=\"r\">xor(T, T) # XOR\r\n<\/code><\/pre>\n<pre>## [1] FALSE\r\n<\/pre>\n<pre><code class=\"r\">x = NA\r\nisTRUE(x == 3) # robust to NAs\r\n<\/code><\/pre>\n<pre>## [1] FALSE\r\n<\/pre>\n<ul>\n<li>R\uc5d0\uc11c \ub17c\ub9ac\uac12\uc740 <code>TRUE<\/code>, <code>FALSE<\/code>, <code>T<\/code>, <code>F<\/code>\uc73c\ub85c \ub098\ud0c0\ub0bc \uc218 \uc788\ub2e4. \uc774\ub54c <code>TRUE<\/code>\ub294 \ud56d\uc0c1 \u2018\ucc38\u2019\uc744 \ub098\ud0c0\ub0b8\ub2e4. R\uc5d0\uc11c <code>TRUE<\/code>\ub294 \u2018\ucc38\u2019\uc744 \ub098\ud0c0\ub0b4\ub294 \uc608\uc57d\uc5b4(keyword)\ub85c \ub2e4\ub978 \uc758\ubbf8\uac00 \ubd80\uc5ec\ub420 \uc218 \uc5c6\ub2e4. \ubc18\uba74 <code>T<\/code>\uc640 <code>F<\/code>\ub294 R\uc5d0\uc11c <code>TRUE<\/code>\uc640 <code>FALSE<\/code>\ub85c \ubbf8\ub9ac \uac12\uc744 \ubd80\uc5ec\ud558\uc600\uc9c0\ub9cc \ubcc0\uacbd\ub420 \uc218 \uc788\ub2e4. \ub2e4\uc74c\uc758 \ucf54\ub4dc\ub97c \ud1b5\ud574 \ud655\uc778\ud574 \ubcf4\uc790. \ub530\ub77c\uc11c \ucc38\/\uac70\uc9d3\uc744 <code>TRUE<\/code>\/<code>FALSE<\/code>\ub85c \uc4f0\uba74 \ud639\uc2dc\ub77c\ub3c4 <code>T<\/code>\/<code>F<\/code>\uc758 \uac12\uc774 \ubcc0\ud560 \ub54c\uc5d0\ub3c4 \uc815\uc0c1\uc801\uc73c\ub85c \ud504\ub85c\uadf8\ub7a8\uc774 \uc791\ub3d9\ud55c\ub2e4.<\/li>\n<\/ul>\n<pre><code class=\"r\">TRUE &lt;- c(3,2) \r\n<\/code><\/pre>\n<pre>## Error in TRUE &lt;- c(3, 2): invalid (do_set) left-hand side to assignment\r\n<\/pre>\n<pre><code class=\"r\">T &lt;- c(3,2) \r\nT \r\n<\/code><\/pre>\n<pre>## [1] 3 2\r\n<\/pre>\n<pre><code class=\"r\">T &lt;- TRUE\r\n<\/code><\/pre>\n<p>\ucc38\uace0\uc790\ub8cc&gt; <a href=\"https:\/\/stat.ethz.ch\/R-manual\/R-devel\/library\/base\/html\/Logic.html\">https:\/\/stat.ethz.ch\/R-manual\/R-devel\/library\/base\/html\/Logic.html<\/a><\/p>\n<h3>\uc815\ub9ac<\/h3>\n<table>\n<thead>\n<tr>\n<th align=\"center\">\ub370\uc774\ud130 \ud0c0\uc785<\/th>\n<th align=\"center\">\uc5f0\uc0b0\uacfc \ud568\uc218<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td align=\"center\">\uc22b\uc790(<code>numeric<\/code>)<\/td>\n<td align=\"center\"><code>^<\/code>(<code>**<\/code>), <code>*<\/code>, <code>\/<\/code>, <code>+<\/code>, <code>-<\/code>, <code>&lt;<\/code>, <code>==<\/code>, <code>&gt;<\/code>, <code>exp()<\/code>, <code>log()<\/code>, \u2026<\/td>\n<\/tr>\n<tr>\n<td align=\"center\">\ubb38\uc790(<code>character<\/code>)<\/td>\n<td align=\"center\"><code>nchar()<\/code>, <code>paste()<\/code>, <code>substring()<\/code><\/td>\n<\/tr>\n<tr>\n<td align=\"center\">\ub0a0\uc9dc(<code>Date<\/code>)<\/td>\n<td align=\"center\"><code>Sys.Date()<\/code>, <code>-<\/code>, <code>difftime()<\/code><\/td>\n<\/tr>\n<tr>\n<td align=\"center\">\ub0a0\uc9dc\uc2dc\uac04(<code>POSIXct<\/code>)<\/td>\n<td align=\"center\"><code>Sys.time()<\/code>, <code>-<\/code>, <code>difftime()<\/code><\/td>\n<\/tr>\n<tr>\n<td align=\"center\">\ub17c\ub9ac(<code>logical<\/code>)<\/td>\n<td align=\"center\"><code>&amp;<\/code>, <code>!<\/code>, <code>xor()<\/code>, <code>&amp;&amp;<\/code>,<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n","protected":false},"excerpt":{"rendered":"<p>\uc5f0\uc0b0(Operations)\uacfc \ud568\uc218(Functions) \uc22b\uc790(numeric) \uc0b0\uc220\uc5f0\uc0b0(Arithmetic operations) 3 + 2 5 &#8211; 4 3 * 2 72 \/ 2 3 ^ 4 3 ** 4 3 ^ (1\/2) sqrt(3) 3 &#8211; 2 + 2 * 4 \/ 2 ^ (1 + 1) # PEMDAS(Parenthesize , Exponentiate , Multiply , Divide, Add, Subtract) 7 \/ 3 # Float [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":2470,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[28,132,133],"tags":[137,135,139,138,134,136],"jetpack_featured_media_url":"http:\/\/ds.sumeun.org\/wp-content\/uploads\/2019\/01\/dessert-g2fc13a181_640.jpg","_links":{"self":[{"href":"http:\/\/ds.sumeun.org\/index.php?rest_route=\/wp\/v2\/posts\/879"}],"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=879"}],"version-history":[{"count":6,"href":"http:\/\/ds.sumeun.org\/index.php?rest_route=\/wp\/v2\/posts\/879\/revisions"}],"predecessor-version":[{"id":2471,"href":"http:\/\/ds.sumeun.org\/index.php?rest_route=\/wp\/v2\/posts\/879\/revisions\/2471"}],"wp:featuredmedia":[{"embeddable":true,"href":"http:\/\/ds.sumeun.org\/index.php?rest_route=\/wp\/v2\/media\/2470"}],"wp:attachment":[{"href":"http:\/\/ds.sumeun.org\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=879"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/ds.sumeun.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=879"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/ds.sumeun.org\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=879"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}