How to Apply the dimnames() Function in R (2 Examples)
In this post you’ll learn how to get and set the dimension names of a data set using the dimnames() function in the R programming language.
Example Data
data(iris) # Example data head(iris) # Sepal.Length Sepal.Width Petal.Length Petal.Width Species # 1 5.1 3.5 1.4 0.2 setosa # 2 4.9 3.0 1.4 0.2 setosa # 3 4.7 3.2 1.3 0.2 setosa # 4 4.6 3.1 1.5 0.2 setosa # 5 5.0 3.6 1.4 0.2 setosa # 6 5.4 3.9 1.7 0.4 setosa |
data(iris) # Example data head(iris) # Sepal.Length Sepal.Width Petal.Length Petal.Width Species # 1 5.1 3.5 1.4 0.2 setosa # 2 4.9 3.0 1.4 0.2 setosa # 3 4.7 3.2 1.3 0.2 setosa # 4 4.6 3.1 1.5 0.2 setosa # 5 5.0 3.6 1.4 0.2 setosa # 6 5.4 3.9 1.7 0.4 setosa
Example 1: Get Dimnames of Data Frame Object
dimnames(iris) # Retrieve names of dimensions # [[1]] # [1] "1" "2" "3" "4" "5" "6" "7" "8" "9" "10" "11" "12" "13" "14" "15" "16" "17" "18" "19" "20" "21" "22" "23" "24" "25" "26" "27" "28" "29" "30" "31" "32" "33" "34" "35" "36" # [37] "37" "38" "39" "40" "41" "42" "43" "44" "45" "46" "47" "48" "49" "50" "51" "52" "53" "54" "55" "56" "57" "58" "59" "60" "61" "62" "63" "64" "65" "66" "67" "68" "69" "70" "71" "72" # [73] "73" "74" "75" "76" "77" "78" "79" "80" "81" "82" "83" "84" "85" "86" "87" "88" "89" "90" "91" "92" "93" "94" "95" "96" "97" "98" "99" "100" "101" "102" "103" "104" "105" "106" "107" "108" # [109] "109" "110" "111" "112" "113" "114" "115" "116" "117" "118" "119" "120" "121" "122" "123" "124" "125" "126" "127" "128" "129" "130" "131" "132" "133" "134" "135" "136" "137" "138" "139" "140" "141" "142" "143" "144" # [145] "145" "146" "147" "148" "149" "150" # # [[2]] # [1] "Sepal.Length" "Sepal.Width" "Petal.Length" "Petal.Width" "Species" |
dimnames(iris) # Retrieve names of dimensions # [[1]] # [1] "1" "2" "3" "4" "5" "6" "7" "8" "9" "10" "11" "12" "13" "14" "15" "16" "17" "18" "19" "20" "21" "22" "23" "24" "25" "26" "27" "28" "29" "30" "31" "32" "33" "34" "35" "36" # [37] "37" "38" "39" "40" "41" "42" "43" "44" "45" "46" "47" "48" "49" "50" "51" "52" "53" "54" "55" "56" "57" "58" "59" "60" "61" "62" "63" "64" "65" "66" "67" "68" "69" "70" "71" "72" # [73] "73" "74" "75" "76" "77" "78" "79" "80" "81" "82" "83" "84" "85" "86" "87" "88" "89" "90" "91" "92" "93" "94" "95" "96" "97" "98" "99" "100" "101" "102" "103" "104" "105" "106" "107" "108" # [109] "109" "110" "111" "112" "113" "114" "115" "116" "117" "118" "119" "120" "121" "122" "123" "124" "125" "126" "127" "128" "129" "130" "131" "132" "133" "134" "135" "136" "137" "138" "139" "140" "141" "142" "143" "144" # [145] "145" "146" "147" "148" "149" "150" # # [[2]] # [1] "Sepal.Length" "Sepal.Width" "Petal.Length" "Petal.Width" "Species"
Example 2: Set Dimnames of Data Frame Object
dimnames(iris) <- list(paste0("r_", 1:150), # Specify names of dimensions paste0("x_", 1:5)) head(iris) # x_1 x_2 x_3 x_4 x_5 # r_1 5.1 3.5 1.4 0.2 setosa # r_2 4.9 3.0 1.4 0.2 setosa # r_3 4.7 3.2 1.3 0.2 setosa # r_4 4.6 3.1 1.5 0.2 setosa # r_5 5.0 3.6 1.4 0.2 setosa # r_6 5.4 3.9 1.7 0.4 setosa |
dimnames(iris) <- list(paste0("r_", 1:150), # Specify names of dimensions paste0("x_", 1:5)) head(iris) # x_1 x_2 x_3 x_4 x_5 # r_1 5.1 3.5 1.4 0.2 setosa # r_2 4.9 3.0 1.4 0.2 setosa # r_3 4.7 3.2 1.3 0.2 setosa # r_4 4.6 3.1 1.5 0.2 setosa # r_5 5.0 3.6 1.4 0.2 setosa # r_6 5.4 3.9 1.7 0.4 setosa