`i`

Imaginary unit, the square root of -1.

Syntax

z = i

The imaginary unit, the complex number 0 + 1i.

z = a + b*i

Builds a complex number from its real part a and imaginary part b.

Description

i is a built-in function that returns the imaginary unit. Because it is only a name, assigning to a variable called i (a very common loop index) hides it, and 2 + 3*i then uses the variable instead. The imaginary literals 1i, 3j and 2.5i are immune to this: a number followed directly by i or j is always imaginary, so they are the safer way to write complex constants.

j is an equivalent alias, popular in engineering.

Output arguments

z: Complex scalar of class double.

Example

Complex arithmetic

i^2
z = 2 + 3*i
abs(z)
exp(1i*pi/2)

Output

ans = -1
z = 2.0000 + 3.0000i
ans = 3.6056
ans = 6.1232e-17 + 1.0000i

i

Syntax

Description

Output arguments

Example

Complex arithmetic

See also

`i`