{"id":1770,"date":"2016-08-14T14:11:27","date_gmt":"2016-08-14T13:11:27","guid":{"rendered":"http:\/\/pcool.dyndns.org:8080\/statsbook\/?page_id=1770"},"modified":"2025-06-23T17:52:31","modified_gmt":"2025-06-23T16:52:31","slug":"objects-and-operators","status":"publish","type":"page","link":"https:\/\/pcool.dyndns.org\/index.php\/objects-and-operators\/","title":{"rendered":"Objects and Operators"},"content":{"rendered":"\n

Objects in R<\/strong><\/p>\n\n\n\n

Vector:<\/strong><\/em> one dimensional array; the elements all have the same type<\/p>\n\n\n\n

my_vector <- c(1,2,3,4,5)<\/span><\/em>\n my_vector<\/span><\/em>\n[1] 1 2 3 4 5<\/span><\/em><\/code><\/pre>\n\n\n\n
Matrix<\/strong>: <\/em>two dimensions of same type; ie matrix(c(1:9),byrow = TRUE, nrow = 3)<\/em> )<\/p>\n\n\n\n
my_matrix <- matrix(c(1,2,3,4,5,6,7,8,9), byrow = TRUE, nrow = 3)<\/em><\/span>\nmy_matrix<\/em><\/span>\n\u00a0\u00a0\u00a0\u00a0 [,1] [,2] [,3]<\/em><\/span>\n[1,]\u00a0\u00a0\u00a0 1\u00a0\u00a0\u00a0 2\u00a0\u00a0\u00a0 3<\/em><\/span>\n[2,]\u00a0\u00a0\u00a0 4\u00a0\u00a0\u00a0 5\u00a0\u00a0\u00a0 6<\/em><\/span>\n[3,]\u00a0\u00a0\u00a0 7\u00a0\u00a0\u00a0 8\u00a0\u00a0\u00a0 9<\/em><\/span><\/code><\/pre>\n\n\n\n
or:<\/p>\n\n\n\n
my_matrix <- matrix(c(1:9), byrow = TRUE, nrow = 3)<\/em><\/span>\nmy_matrix<\/em><\/span>\n\u00a0\u00a0\u00a0\u00a0 [,1] [,2] [,3]<\/em><\/span>\n[1,]\u00a0\u00a0\u00a0 1\u00a0\u00a0\u00a0 2\u00a0\u00a0\u00a0 3<\/em><\/span>\n[2,]\u00a0\u00a0\u00a0 4\u00a0\u00a0\u00a0 5\u00a0\u00a0\u00a0 6<\/em><\/span>\n[3,]\u00a0\u00a0\u00a0 7\u00a0\u00a0\u00a0 8\u00a0\u00a0\u00a0 9<\/em><\/span><\/code><\/pre>\n\n\n\n
Data frame<\/strong> <\/em>could contain different data types in different columns<\/p>\n\n\n\n
List<\/strong><\/em> can contain combinations of dataframes, vectors other lists etc<\/p>\n\n\n\n
Factors<\/strong><\/p>\n\n\n\n
to be added<\/em><\/p>\n\n\n\n
Operators in R<\/strong><\/p>\n\n\n\n
to be added<\/em><\/p>\n\n\n\n
R operators:<\/strong><\/p>\n\n\n\n
Arithmetic operators<\/strong><\/p>\n\n\n\n
<-   =  (ie x<-5 define x as number 5)<\/p>\n\n\n\n
+   addition (ie: 5+2=7)<\/p>\n\n\n\n
–  subtraction (ie 5-2=3)<\/p>\n\n\n\n
*   multiplication (ie 5*3=15)<\/p>\n\n\n\n
\/   division (ie 6\/3=2)<\/p>\n\n\n\n
^   exponent (ie 5^2=25)<\/p>\n\n\n\n
x %% y   modulus (ie 5%%3 =2)<\/p>\n\n\n\n
x %\/% y integer division (ie 5%\/%3=1)<\/p>\n\n\n\n
Logical operators<\/strong><\/p>\n\n\n\n
<   Less than<\/p>\n\n\n\n
<=   less than or equal to<\/p>\n\n\n\n
>   more than<\/p>\n\n\n\n
>=   more than or equal to<\/p>\n\n\n\n
==   is equal to<\/p>\n\n\n\n
!   not<\/p>\n\n\n\n
&   and<\/p>\n\n\n\n
|   or<\/p>\n\n\n\n
isTRUE(x)   is x true?  (ie<\/span> isTRUE(5<4),<\/span> <\/em><\/span> FALSE<\/span><\/em>)<\/p>\n\n\n\n
is.na(x)   is ‘not available’ (NA) (ie x<-5,<\/span> is.na(x)<\/em>,<\/span><\/span> FALSE)<\/span><\/span><\/em><\/p>\n\n\n\n
!(is.na(x))   is not ‘not available (NA) (ie x<-5<\/em><\/span>, !(is.na(x))<\/span><\/em>, TRUE<\/span>)<\/em><\/p>\n\n\n\n
ifelse(test, yes, no)  if test condition is true ‘yes’, otherwise ‘no’<\/p>\n\n\n\n
Relational Operators<\/strong><\/p>\n\n\n\n
types and examples<\/em><\/p>\n\n\n\n
Logical Operators<\/strong><\/p>\n\n\n\n
types and examples<\/em><\/p>\n\n\n\n
Conditional Operators<\/strong><\/p>\n\n\n\n
types and examples<\/em><\/p>\n","protected":false},"excerpt":{"rendered":"
Objects in R Vector: one dimensional array; the elements all have the same type Matrix: two dimensions of same type; ie matrix(c(1:9),byrow = TRUE, nrow = 3) ) or: Data frame could contain different data types in different columns List can contain combinations of dataframes, vectors other lists etc Factors to be added Operators in […]<\/p>\n","protected":false},"author":2,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"inline_featured_image":false,"footnotes":""},"class_list":["post-1770","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/pcool.dyndns.org\/index.php\/wp-json\/wp\/v2\/pages\/1770","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/pcool.dyndns.org\/index.php\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/pcool.dyndns.org\/index.php\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/pcool.dyndns.org\/index.php\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/pcool.dyndns.org\/index.php\/wp-json\/wp\/v2\/comments?post=1770"}],"version-history":[{"count":2,"href":"https:\/\/pcool.dyndns.org\/index.php\/wp-json\/wp\/v2\/pages\/1770\/revisions"}],"predecessor-version":[{"id":4293,"href":"https:\/\/pcool.dyndns.org\/index.php\/wp-json\/wp\/v2\/pages\/1770\/revisions\/4293"}],"wp:attachment":[{"href":"https:\/\/pcool.dyndns.org\/index.php\/wp-json\/wp\/v2\/media?parent=1770"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}