complex

R Base 3.6.2

Basic functions which support complex arithmetic in R, in addition to the arithmetic operators +, -, *, /, and ^.

Syntax

complex(length.out = 0, real = numeric(), imaginary = numeric(),
        modulus = 1, argument = 0)
as.complex(x, &#8230;)
is.complex(x)<p></p><p>Re(z)
Im(z)
Mod(z)
Arg(z)
Conj(z)</p>

Arguments

Parameter	Description
`length.out`	numeric. Desired length of the output vector, inputs being recycled as needed.
`real`	numeric vector.
`imaginary`	numeric vector.
`modulus`	numeric vector.
`argument`	numeric vector.
`x`	an object, probably of mode complex.
`z`	an object of mode complex, or one of a class for which a methods has been defined.
`…`	further arguments passed to or from other methods.

Details

Complex vectors can be created with complex. The vector can be specified either by giving its length, its real and imaginary parts, or modulus and argument. (Giving just the length generates a vector of complex zeroes.) as.complex attempts to coerce its argument to be of complex type: like as.vector it strips attributes including names. Up to R versions 3.2.x, all forms of NA and NaN were coerced to a complex NA, i.e., the NA_complex_ constant, for which both the real and imaginary parts are NA. Since R 3.3.0, typically only objects which are NA in parts are coerced to complex NA, but others with NaN parts, are not. As a consequence, complex arithmetic where only NaN's (but no NA's) are involved typically will not give complex NA but complex numbers with real or imaginary parts of NaN. Not

Examples

Example

# NOT RUN {
require(graphics)

0i ^ (-3:3)

matrix(1i^ (-6:5), nrow = 4) #- all columns are the same
0 ^ 1i # a complex NaN

## create a complex normal vector
z <- complex(real = stats::rnorm(100), imaginary = stats::rnorm(100))
## or also (less efficiently):
z2 <- 1:2 + 1i*(8:9)

## The Arg(.) is an angle:
zz <- (rep(1:4, len = 9) + 1i*(9:1))/10
zz.shift <- complex(modulus = Mod(zz), argument = Arg(zz) + pi)
plot(zz, xlim = c(-1,1), ylim = c(-1,1), col = "red", asp = 1,
     main = expression(paste("Rotation by "," ", pi == 180^o)))
abline(h = 0, v = 0, col = "blue", lty = 3)
points(zz.shift, col = "orange")

showC <- function(z) noquote(sprintf("(R = %g, I = %g)", Re(z), Im(z)))

## The exact result of this *depends* on the platform, compiler, math-library:
(NpNA <- NaN + NA_complex_) ; str(NpNA) # *behaves* as 'cplx NA' ..
stopifnot(is.na(NpNA), is.na(NA_complex_), is.na(Re(NA_complex_)), is.na(Im(NA_complex_)))
showC(NpNA)# but not always is {shows  '(R = NaN, I = NA)' on some platforms}
## and this is not TRUE everywhere:
identical(NpNA, NA_complex_)
showC(NA_complex_) # always == (R = NA, I = NA)
# }

complex

Syntax

Arguments

Details

Examples

See Also