A numeric constant may be a scalar, a vector, or a matrix, and it may contain complex values.
The simplest form of a numeric constant, a scalar, is a single number that can be an integer, a decimal fraction, a number in scientific (exponential) notation, or a complex number. Note that by default numeric constants are represented within Octave in double-precision floating point format (complex constants are stored as pairs of double-precision floating point values). It is however possible to represent real integers as described in Integer Data Types. Here are some examples of real-valued numeric constants, which all have the same value:
105
1.05e+2
1050e-1
To specify complex constants, you can write an expression of the form
3 + 4i
3.0 + 4.0i
0.3e1 + 40e-1i
all of which are equivalent. The letter i in the previous example
stands for the pure imaginary constant, defined as
sqrt (-1).
For Octave to recognize a value as the imaginary part of a complex constant, a space must not appear between the number and the i. If it does, Octave will print an error message, like this:
octave:13> 3 + 4 i
parse error:
syntax error
>>> 3 + 4 i
^
You may also use j, I, or J in place of the i above. All four forms are equivalent.
Return a complex result from real arguments. With 1 real argument x, return the complex result x
+ 0i. With 2 real arguments, return the complex result re+im.complexcan often be more convenient than expressions such asa + i*b. For example:complex ([1, 2], [3, 4]) => 1 + 3i 2 + 4i