1. feladat. Sorok és oszlopok száma.
Írassunk ki aMASScsomagsurveyadattáblájáról néhány információt: sorok és oszlopok száma!
data(survey, package = "MASS")
str(survey) # 1. verzió
'data.frame': 237 obs. of 12 variables:
$ Sex : Factor w/ 2 levels "Female","Male": 1 2 2 2 2 1 2 1 2 2 ...
$ Wr.Hnd: num 18.5 19.5 18 18.8 20 18 17.7 17 20 18.5 ...
$ NW.Hnd: num 18 20.5 13.3 18.9 20 17.7 17.7 17.3 19.5 18.5 ...
$ W.Hnd : Factor w/ 2 levels "Left","Right": 2 1 2 2 2 2 2 2 2 2 ...
$ Fold : Factor w/ 3 levels "L on R","Neither",..: 3 3 1 3 2 1 1 3 3 3 ...
$ Pulse : int 92 104 87 NA 35 64 83 74 72 90 ...
$ Clap : Factor w/ 3 levels "Left","Neither",..: 1 1 2 2 3 3 3 3 3 3 ...
$ Exer : Factor w/ 3 levels "Gyakran","Soha",..: 2 1 1 1 2 2 3 3 2 2 ...
$ Smoke : Factor w/ 4 levels "Heavy","Never",..: 2 4 3 2 2 2 2 2 2 2 ...
$ Height: num 173 178 NA 160 165 ...
$ M.I : Factor w/ 2 levels "Imperial","Metric": 2 1 NA 2 2 1 1 2 2 2 ...
$ Age : num 18.2 17.6 16.9 20.3 23.7 ...
dim(survey) # 2. verzió
[1] 237 12
nrow(survey) # 3. verzió: a sorok száma
[1] 237
ncol(survey) # 4. verzió: az oszlopok száma
[1] 12
length(survey) # 5. verzió: az oszlopok száma
[1] 12
2. feladat. Sorok és oszlopok neve.
Írassunk ki aMASScsomagsurveyadattáblájáról néhány információt: sorok és oszlopok neve!
data(survey, package = "MASS")
str(survey) # 1. verzió: az oszlopok neve
'data.frame': 237 obs. of 12 variables:
$ Sex : Factor w/ 2 levels "Female","Male": 1 2 2 2 2 1 2 1 2 2 ...
$ Wr.Hnd: num 18.5 19.5 18 18.8 20 18 17.7 17 20 18.5 ...
$ NW.Hnd: num 18 20.5 13.3 18.9 20 17.7 17.7 17.3 19.5 18.5 ...
$ W.Hnd : Factor w/ 2 levels "Left","Right": 2 1 2 2 2 2 2 2 2 2 ...
$ Fold : Factor w/ 3 levels "L on R","Neither",..: 3 3 1 3 2 1 1 3 3 3 ...
$ Pulse : int 92 104 87 NA 35 64 83 74 72 90 ...
$ Clap : Factor w/ 3 levels "Left","Neither",..: 1 1 2 2 3 3 3 3 3 3 ...
$ Exer : Factor w/ 3 levels "Gyakran","Soha",..: 2 1 1 1 2 2 3 3 2 2 ...
$ Smoke : Factor w/ 4 levels "Heavy","Never",..: 2 4 3 2 2 2 2 2 2 2 ...
$ Height: num 173 178 NA 160 165 ...
$ M.I : Factor w/ 2 levels "Imperial","Metric": 2 1 NA 2 2 1 1 2 2 2 ...
$ Age : num 18.2 17.6 16.9 20.3 23.7 ...
names(survey) # 2. verzió: az oszlopok neve
[1] "Sex" "Wr.Hnd" "NW.Hnd" "W.Hnd" "Fold" "Pulse" "Clap"
[8] "Exer" "Smoke" "Height" "M.I" "Age"
colnames(survey) # 3. verzió: az oszlopok neve
[1] "Sex" "Wr.Hnd" "NW.Hnd" "W.Hnd" "Fold" "Pulse" "Clap"
[8] "Exer" "Smoke" "Height" "M.I" "Age"
rownames(survey) # 4. verzió: a sorok neve
[1] "1" "2" "3" "4" "5" "6" "7" "8" "9" "10" "11"
[12] "12" "13" "14" "15" "16" "17" "18" "19" "20" "21" "22"
[23] "23" "24" "25" "26" "27" "28" "29" "30" "31" "32" "33"
[34] "34" "35" "36" "37" "38" "39" "40" "41" "42" "43" "44"
[45] "45" "46" "47" "48" "49" "50" "51" "52" "53" "54" "55"
[56] "56" "57" "58" "59" "60" "61" "62" "63" "64" "65" "66"
[67] "67" "68" "69" "70" "71" "72" "73" "74" "75" "76" "77"
[78] "78" "79" "80" "81" "82" "83" "84" "85" "86" "87" "88"
[89] "89" "90" "91" "92" "93" "94" "95" "96" "97" "98" "99"
[100] "100" "101" "102" "103" "104" "105" "106" "107" "108" "109" "110"
[111] "111" "112" "113" "114" "115" "116" "117" "118" "119" "120" "121"
[122] "122" "123" "124" "125" "126" "127" "128" "129" "130" "131" "132"
[133] "133" "134" "135" "136" "137" "138" "139" "140" "141" "142" "143"
[144] "144" "145" "146" "147" "148" "149" "150" "151" "152" "153" "154"
[155] "155" "156" "157" "158" "159" "160" "161" "162" "163" "164" "165"
[166] "166" "167" "168" "169" "170" "171" "172" "173" "174" "175" "176"
[177] "177" "178" "179" "180" "181" "182" "183" "184" "185" "186" "187"
[188] "188" "189" "190" "191" "192" "193" "194" "195" "196" "197" "198"
[199] "199" "200" "201" "202" "203" "204" "205" "206" "207" "208" "209"
[210] "210" "211" "212" "213" "214" "215" "216" "217" "218" "219" "220"
[221] "221" "222" "223" "224" "225" "226" "227" "228" "229" "230" "231"
[232] "232" "233" "234" "235" "236" "237"
3. feladat. Változók típusa.
Írassunk ki aMASScsomagsurveyadattáblájáról néhány információt: az adattábla típusa és az oszlopok típusa!
data(survey, package = "MASS")
class(survey) # a survey típusa
[1] "data.frame"
str(survey) # a survey oszlopainak típusa
'data.frame': 237 obs. of 12 variables:
$ Sex : Factor w/ 2 levels "Female","Male": 1 2 2 2 2 1 2 1 2 2 ...
$ Wr.Hnd: num 18.5 19.5 18 18.8 20 18 17.7 17 20 18.5 ...
$ NW.Hnd: num 18 20.5 13.3 18.9 20 17.7 17.7 17.3 19.5 18.5 ...
$ W.Hnd : Factor w/ 2 levels "Left","Right": 2 1 2 2 2 2 2 2 2 2 ...
$ Fold : Factor w/ 3 levels "L on R","Neither",..: 3 3 1 3 2 1 1 3 3 3 ...
$ Pulse : int 92 104 87 NA 35 64 83 74 72 90 ...
$ Clap : Factor w/ 3 levels "Left","Neither",..: 1 1 2 2 3 3 3 3 3 3 ...
$ Exer : Factor w/ 3 levels "Gyakran","Soha",..: 2 1 1 1 2 2 3 3 2 2 ...
$ Smoke : Factor w/ 4 levels "Heavy","Never",..: 2 4 3 2 2 2 2 2 2 2 ...
$ Height: num 173 178 NA 160 165 ...
$ M.I : Factor w/ 2 levels "Imperial","Metric": 2 1 NA 2 2 1 1 2 2 2 ...
$ Age : num 18.2 17.6 16.9 20.3 23.7 ...
# eldöntendő kérdésekkel is választ kaphatunk a teljes adattábla esetén
is.data.frame(survey)
[1] TRUE
is.list(survey)
[1] TRUE
is.matrix(survey)
[1] FALSE
is.factor(survey)
[1] FALSE
is.vector(survey)
[1] FALSE
# eldöntendő kérdésekkel is választ kaphatunk a változók esetén
is.factor(survey$Sex)
[1] TRUE
is.numeric(survey$Sex)
[1] FALSE
is.numeric(survey$Wr.Hnd)
[1] TRUE
is.factor(survey$Wr.Hnd)
[1] FALSE