dec2bin is adding inappropriate 0s to negative numbers when numBits is specified

e.g. dec2bin(-23, 10) produces '0011101001', but it should produce '1111101001'.

[Andrew]

My version doesn't specify that non-negative numbers are a problem. For example, it correctly converts -23 when numBits isn't specified.

[Stephen23]

@David Goodmanson:

"Starting in R2020a, the dec2bin function converts negative numbers using their two's complement binary values."

source. https://www.mathworks.com/help/matlab/ref/dec2bin.html#mw_a9ca0a09-b68d-4478-a0a1-5e4167a2e777

Answer 1

[Fangjun Jiang]

Report to tech support. I think it looks like a bug.

From "doc dec2bin" in R2020a

Starting in R2020a, the dec2bin function converts negative numbers using their two's complement binary values.

version
ans =
    '9.8.0.1376261 (R2020a) Update 2'
dec2bin(-23)
ans =
    '11101001'
dec2bin(-23,8)
ans =
    '11101001'
dec2bin(-23,9)
ans =
    '011101001'

Answer 2

[Walter Roberson]

Yes, it is a bug; if you want to report it yourself (the more people who report, the higher the priority), you can refer to case 04106030