Logical Operations

After reading these notes you should be able to:

Comparison Operators

Spring 2022 Readers: Dave tried to write too many notes this week. Please read the following in place of this under construction section:

  • TODO: note about odd naming
  • TODO: change to “comparison” operators?
  • TODO: table of operators and meanings
  • TODO: These will produce logical values
?Comparison
?`%in%`
  • TODO: indentical(), all.equal()
1 == 1L
[1] TRUE
identical(1, 1L)
[1] FALSE
0.1 + 0.2 == 0.3
[1] FALSE
all.equal(0.1 + 0.2, 0.3)
[1] TRUE

Boolean Operations

Spring 2022 Readers: Dave tried to write too many notes this week. Please read the following in place of this under construction section:

  • TODO: these are operations on logic values (they often work on numeric values, expect coercion)
  • TODO: https://en.m.wikipedia.org/wiki/Truth_table
?base::Logic
  • TODO: vector in, vector out, vs vector in, vector of length one out
?any
?all
x = c(TRUE, TRUE, FALSE, FALSE)
y = c(TRUE, FALSE, TRUE, FALSE)
data.frame(
  x = x,
  y = y,
  `!x` = !x, # not
  `x & y` = x & y, # and
  `x | y` = x | y, # or
  `xor(x, y)` = xor(x, y), # exclusive or
  check.names = FALSE
)
      x     y    !x x & y x | y xor(x, y)
1  TRUE  TRUE FALSE  TRUE  TRUE     FALSE
2  TRUE FALSE FALSE FALSE  TRUE      TRUE
3 FALSE  TRUE  TRUE FALSE  TRUE      TRUE
4 FALSE FALSE  TRUE FALSE FALSE     FALSE

Logical Subsetting

Spring 2022 Readers: Dave tried to write too many notes this week. Please read the following in place of this under construction section:

  • TODO: proportion between example
  • TODO: example with data frames rows

Summary

  • TODO: You’ve learned to…

What’s Next?

  • TODO: control flow, etc.

TODO

  • TODO: ?intersect
  • TODO: which