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Question 1

How to sample a vector in R?

Answer 1

sample(y, size, replace, prob=vector), replace = do i want to place the item back in there or leave it out so it cant be selected again.

Question 2

Logical vectors?

Answer 2

A vector but with different elements than just numbers, such as booleans

Question 3

Negation in R (true values into false values and vise aversa)?

Answer 3

!vector

Question 4

And operator (return a true if both values are true)?

Answer 4

vector1 & vector2

Question 5

Or operator (returns a true value if at least one of the values is true)?

Answer 5

vector1 | vector2

Question 6

What happens if you take the inequality of two vectors?

Answer 6

It returns true or false depending on whether the inequality of those elements hold

Question 7

all(z)?

Answer 7

Checks to see if all the elements are true in a logical vector?

Question 8

any(vector)?

Answer 8

Return true if at least one of them is true

Question 9

Filter elements using logical vectors?

Answer 9

vector[logical vector], filters out all the falses, or, vector[condition such as an inequality]

Question 10

How to do an if else in one line?

Answer 10

ifelse(test, output, else)

Example

x = 1, 2, 3, 4, 5, 6, 7, 8

ifelse(x == 8, x, -x): -1, -2, -3, -4, -5, -6, -7, 8

Question 11

Factor function in R?

Answer 11

factor(x, level = vector), level is telling the program that there were other possible values, but some of those values are missing from the actual vector.

Question 12

Why is the factor function useful?

Answer 12

If you run table(factor(x)), then it counts how many times each value occurs, including the missing values.

Question 13

& operator in R?

Answer 13

Compares the logical value of two entire vectors and returns true if the two elements are true.

Question 14

If you have && or || when comparing logical vectors, this means?

Answer 14

Scaler; only comparing the first element.

Question 15

Union of two vectors?

Answer 15

union(x, y)

Question 16

Intersection of both vectors?

Answer 16

intersect(x, y)

Question 17

Removing an element from vector x if it shows up in vector y?

Answer 17

setdiff(x, y)

Question 18

Check to see if two vectors are equal?

Answer 18

setequal(x, y)

Question 19

Is element f in vector x?

Answer 19

“F” %in% x

Question 20

asp?

Answer 20

Aspect ratio when a change x in the horizontal axis is the change y in the vertical axis.

Question 21

abline?

Answer 21

Plotting lines from a defined number of lines, either v as vertical or h as horizontal

Question 22

removing white borders of plot.new?

Answer 22

par(mar = c(x, y, h, z)))

Question 23

How to add axis to a plot?

Answer 23

axis(1 or 2 or 3 or 4, at = x:y, levels = x:y, cex.axis = z, pos = j, las = k)

Question 24

Add text to a pre-existing plot?

Answer 24

text(x, y, “Text”, pos = h)

Question 25

Adding titles to pre existing plot?

Answer 25

title(main = “text”, xlab = “text”, ylab = “text”)

Question 26

add curve to pre existing plot?

Answer 26

curve(function, xlim = c(x, y), add = TRUE)

Question 27

Add polygon to pre existing plot?

Answer 27

polygon(c(x, y, z, h), c(k, l, a, s)) where a plot is plotted at (x, y) and (y, l)…