3行2列的矩阵A,修改A的行号为"甲","乙","丙"的命令是:
A: rownames(A)<-c("甲","乙","丙")
B: rowname(A)<-c("甲","乙","丙")
C: colnames(A)<-c("甲","乙","丙")
D: colname(A)<-c("甲","乙","丙")
A: rownames(A)<-c("甲","乙","丙")
B: rowname(A)<-c("甲","乙","丙")
C: colnames(A)<-c("甲","乙","丙")
D: colname(A)<-c("甲","乙","丙")
举一反三
- 3行2列的矩阵A,修改A的行号为"甲","乙","丙"的命令是: A: rownames(A)<-c("甲","乙","丙") B: rowname(A)<-c("甲","乙","丙") C: colnames(A)<-c("甲","乙","丙") D: colname(A)<-c("甲","乙","丙")
- 要把数据框x的行名修改为:"甲", "乙", "丙"的语句是: ( ) A: rownames(x) <- c("甲", "乙", "丙") B: names(x) <- c("甲", "乙", "丙") C: colnames(x) <- c("甲", "乙", "丙") D: rowname(x) <- c("甲", "乙", "丙")
- A、B、C、D四个人对甲、乙、丙三个方案投票表决,具有双峰形偏好的是()。 A: 甲>乙>丙 B: 丙>乙>甲 C: 丙>甲>乙 D: 乙>丙>甲
- 霍乱、艾滋病、病毒性肝炎和血吸虫病分别属于哪一类传染病? A: 甲、乙、丙、丙 B: 甲、甲、乙、乙 C: 甲、甲、乙、丙 D: 甲、乙、乙、丙 E: 甲、乙、乙、乙
- 以下检索出文献最少的检索式是()。 A: 甲and(乙or丙) B: 甲and乙or丙 C: 甲and乙and丙 D: (甲or乙)and丙