Q.1
Which of the following will reverse the order of values in x?
  • a) rev(x)
  • b) max(x, na.rm=TRUE)
  • c) all(x)
  • d) x%in%y
Q.2
Which of the following finds row sums for each level of a grouping variable?
  • a) rowSums (x, na.rm = FALSE, dims = 1)
  • b) colMeans(x, na.rm = FALSE, dims = 1)
  • c) rowMeans(x, na.rm = FALSE, dims = 1)
  • d) rowsum(x, group, reorder = TRUE, …)
Q.3
Which of the following statement applies the function (FUN) to either rows (or columns (on object X?
  • a) apply(x,1,min)
  • b) apply(x,2,max)
  • c) col.max(x)
  • d) apply(X, MARGIN, FUN, …)
Q.4
Which of the following statement finds the maximum for each column?
  • a) apply(x,2,max)
  • b) col.max(x)
  • c) which.min(x)
  • d) which.max(x)
Q.5
which of the following statement tells the row with the minimum value for every column?
  • a) which.min(x)
  • b) which.max(x)
  • c) z=apply(x,1,which.min)
  • d) z=apply(1,1,which.max)
Q.6
Which of the following may be used for linear regression?
  • a) X %*% Y
  • b) solve(A)
  • c) solve(A,B)
  • d) X $*$ Y
Q.7
Which of the following finds row sums for each level of a grouping variable?
  • a) as.numeric(x)
  • b) rowsum(x, group, reorder = TRUE, …)
  • c) as.order(x)
  • d) colSums (x, na.rm = FALSE, dims = 1)
Q.8
Which of the following sets the size of the outer margins for the graph?
  • a) par(mfrow=c(nrow,mcol))
  • b) par(ask=TRUE)
  • c) par(omi=c(0,0,1,0) )
  • d) par(ask=False)
Q.9
Which of the following function is used for plotting histogram?
  • a) hist()
  • b) histog()
  • c) histg()
  • d) histo()
Q.10
Which of the following will add the title “R language” to the graph?
  • a) titleAdd( “R language”)
  • b) title( “R language”)
  • c) titleBar( “R language”)
  • d) var(x, na.rm=TRUE)
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