R语言简单的运行

以前没有接触过R语言，第一天学习R语言，生信技能树团队的齐老师安排作业给我，我觉得有作业才有目标性和动力去搜索资源。通过网络搜索和参考相关书籍以及齐老师的指导，顺利地完成作业：
1.创建一个向量元素为a,b,e,2,5

work <- c(a,b,e)
data <- c(2,5)

2.确定上述向量中每个元素的数据类型

> class(work[1])
[1] "character"
> class(work[2])
[1] "character"
> class(work[3])
[1] "character"
> class(data[1])
[1] "numeric"
> class(data[2])
[1] "numeric"

3.创建一个包含字符和数值的数据框（5行3列）

patientID <- c(1,2,3,4,5)
age <- c(25,32,38,43,60)
breastcancer <- c("Type1","Type1","Type3","Type1","Type2")
patientdata <- data.frame(patientID,age,breastcancer)
patientdata
  patientID age breastcancer
1         1  25        Type1
2         2  32        Type1
3         3  38        Type3
4         4  43        Type1
5         5  60        Type2

4.对上述数据框的行名和列名进行更改

rownames(patientdata) <- c("a","b","c","d","e")
colnames(patientdata) <- c("personalities","years","cancer")
patientdata
  personalities years cancer
a             1    25  Type1
b             2    32  Type1
c             3    38  Type3
d             4    43  Type1
e             5    60  Type2

5.确定数据框中各列的数据类型

class(patientdata[,1])
class(patientdata[,2])
class(patientdata[,3])
> class(patientdata[,1])
[1] "numeric"
> class(patientdata[,2])
[1] "numeric"
> class(patientdata[,3])
[1] "factor"

or

class(patientdata$personalities)
class(patientdata$years)
class(patientdata$cancer)
> class(patientdata$personalities)
[1] "numeric"
> class(patientdata$years)
[1] "numeric"
> class(patientdata$cancer)
[1] "factor"

6.不同方法检索数据框的第3行第2列的元素

patientdata[3,2]
patientdata['c','years']
> patientdata[3,2]
[1] 38
> patientdata['c','years']
[1] 38

7.创建一个矩阵（4行6列）

Y <- matrix(1:20,nrow=5,ncol=4)
Y  
> Y
     [,1] [,2] [,3] [,4]
[1,]    1    6   11   16
[2,]    2    7   12   17
[3,]    3    8   13   18
[4,]    4    9   14   19
[5,]    5   10   15   20

8.对上述矩阵的行名和列名进行更改

colnames(Y)<-c("R1","R2","R3","R4")
rownames(Y)<-c("C1","C2","C3","C4","C5")

 R1 R2 R3 R4
C1  1  6 11 16
C2  2  7 12 17
C3  3  8 13 18
C4  4  9 14 19
C5  5 10 15 20

9.不同方法检索数据框的第3行第2列的元素

Y[3,2]
Y["C3","R2"]

> Y[3,2]
[1] 8
> Y["C3","R2"]
[1] 8

将作业写至简书邮件jmzeng1314@163.com，抄送juanyuanjing@1163.com