## I-J Square Root of Negative One

Section: Base Constants

### Usage

Returns a `complex` value that represents the square root of -1. There are two functions that return the same value:

       y = i

and

       y = j.

This allows either `i` or `j` to be used as loop indices. The returned value is a 32-bit complex value.

### Example

The following examples demonstrate a few calculations with `i`.

    --> i
    ans =
      <complex>  - size: [1 1]
      0+ 1 i
    --> i^2
    ans =
      <complex>  - size: [1 1]
      -1+  0 i

The same calculations with `j`:

    --> j
    ans =
      <complex>  - size: [1 1]
      0+ 1 i
    --> j^2
    ans =
      <complex>  - size: [1 1]
      -1+  0 i

Here is an example of how `i` can be used as a loop index and then recovered as the square root of -1.

    --> accum = 0; for i=1:100; accum = accum + i; end; accum
    ans =
      <int32>  - size: [1 1]
     5050
    --> i
    ans =
      <int32>  - size: [1 1]
     100
    --> clear i
    --> i
    ans =
      <complex>  - size: [1 1]
      0+ 1 i