- `TF = isreal (X)`

Return true if `X` is not complex.

For numeric arrays, the result is false when any element has a nonzero
imaginary part.

See also: `real`, `imag`, `isnumeric`.

### References

- https://www.mathworks.com/help/matlab/ref/isreal.html
- https://octave.sourceforge.io/octave/function/isreal.html