Problem 1943. Signed Magnitude

Created by Greg in Community

Solve Later

For a given input vector, return the value that is furthest from zero.

For example, if

x = [1 2 -12]

return -12.

Solve

Solution Stats

Last solution submitted on Apr 10, 2019

Last 200 Solutions

Problem Comments

1 Comment

1 Comment

Jon on 9 Apr 2014

Really needs a better test suite that doesn't have the correct answer in the same position.

Solution Comments

Solution 1242349

5 Comments

5 Comments

Show 2 older comments

yurenchu on 30 Jul 2017

Why does this not work?

Peng Liu on 30 Jul 2017

Because x + 0i and complex(x) are fundamentally different in MATLAB. In MATLAB, x+0i is always real variable given that x is real, i.e., it only requires 8 bytes to store x+0i (for real double x), whereas complex(x) is a complex variable which consumes 16 bytes, with 8 bytes storing the real part (x) and 8 bytes storing the imaginary part (which is 0 in this case). You may verify this by the following snippet: [a,b,c] = deal(1,1+0i,complex(1)); whos a b c

yurenchu on 31 Jul 2017

Thanks for your neat and detailed explanation, Peng Liu. I had expected/assumed that "x+0i" would work the same as "complex(x)", because in the description on the MATLAB documentation page of the complex() function, it says "if x is real, then z is x + 0i", without directly mentioning anything about the fundamental difference in how the variable is stored.

Binbin Qi on 1 Aug 2017

@yurenchu, in the bottom of the document of MATLAB , there is a Tip, said "If b contains only zeros, then z is complex and the value of all its imaginary components is 0. In contrast, the addition a + 0i returns a strictly real result."

yurenchu on 1 Aug 2017

Thanks, Binbin Qi. It seems that I had somehow missed/overlooked that part when I read that page earlier.

Problem 1943. Signed Magnitude

Solution Stats

Last 200 Solutions

Problem Comments

Solution Comments

Recent Solvers94

Suggested Problems

Tags

Problem 1943. Signed Magnitude

Solution Stats

Last 200 Solutions

Problem Comments

Solution Comments

Recent Solvers94

Suggested Problems

Tags

Players