mat2str() on complex values with 0 inaginary part

Hi,

Tried mat2str(complex(5,6)) witch seems ok:

ans =

    '5+6i'

But other complex values with imaginary part 0 or 0+0i are printed as real values:

mat2str(complex(5,0))

ans =

    '5'

mat2str(0+0i)

Seems incorect to me, is this a bug ?

Answer 1

[Jan]

Mathematically 5 is the same as 5+0i, so the output is correct.

So omitting the imaginary part is a question of taste.

If you want to display it, do this expliticitly:

x = 1 + 2i;
sprintf('%g %gi', real(x), imag(x))

Alternatively you can copy the code of mat2str to e.g. mat2stri anywhere in your user-defined folders in the path and remove the line:

imagStr(imagVal == 0) = "";

Answer 2

[Firan Lucian]

~isreal(complex(5,0))

ans =

  logical

   1

~isreal(5)

ans =

  logical

   0

Answer 3

[Steven Lord]

Not a bug. Many operations in MATLAB, if the result has an all zero imaginary part, will remove that imaginary part. complex is one of the few operations that does not by design.

x = complex(5, 0)

x = 5.0000 + 0.0000i

y = x(1)

y = 5

z = x + 0

z = 5

[Firan Lucian]

I don't like this output inconsistency, as this functions may provide some human readable string; that should contain, not hide, the complex storage, but this is my opinion…

(maybe some extra options could help ...,'complex', true)