octal to binary, flip the binary, convert to hex

I have a unique situation where I must take an octal label (e.g., '52') and ultimately arrive at a hex value that happens to be the flipped version of the binary of the octal. Poor wording... I know. Here is an example:

Octal label = 52

Binary of octal 52 = 00101010

Flipped binary of octal 52 = 01010100

Hex of flipped binary of octal 52 = 54

I have 78 different octal numbers I may have to do this for and am looking for a simple solution. The complicated part for me is the fact that MATLAB drops off the leading zeroes, so using fliplr() doesn't help too much when trying to flip the binary number. Here is what I have so far:

for i = 1:length(chosenLabels)
  chosenLables(i) = bin2hex(fliplr(dec2bin(base2dec(chosenLabels(i), 8))));
end

This is how I found out bin2hex isn't a function :) And as I said, I know the fliplr isn't going to work. Ideally, one line of code would be awesome but I'm guessing I may need to use a for loop and create a binary vector that includes the leading zeroes.

Answer 1

[Joseph Cheng]

You can try something like this

octstr = ['52';'51'];   %your oct inputs
bin_str = dec2bin(base2dec(octstr,8),8)  %convert to decimal using base 8 and 8 indexes long.  

bin_str=bin_str(:,end:-1:1)  %reverse the binary
hexstr = dec2hex(bin2dec(bin_str)) %convert bin->dec->hex

and you don't even need a for loop!

[Adam Kaas]

This is incredibly close to what I need. The difference is my chosenLables array is a 1x9 double and base2dec() doesn't like it. I did a num2str(chosenLabels) and it liked it, but the answer isn't readable as my binary string is one very long string of binary with no separation. Suggestions? I apologize... I'm not the most well versed MATLAB user.

[Adam Kaas]

Here's what I ended up doing.

bin_str = dec2bin(oct2dec(chosenLabels),8);
bin_str = bin_str(:,end:-1:1);
hexstr = dec2hex(bin2dec(bin_str));

Thanks for the pointers in the right direction Joseph!

[Joseph Cheng]

So you're saying the octal number is not a string but an octal number written as a decimal number?

then you can do this.

clc,clear all;
octdouble = [46    46    23    35     5     4    32    47    57];
octstr = num2str(octdouble')
octstr(octstr==' ')='0'
bin_str = dec2bin(base2dec(octstr,8),8)
bin_str=bin_str(:,end:-1:1)
hexstr = dec2hex(bin2dec(bin_str))

[Joseph Cheng]

you don't need to ' ' to '0' substitution. got a random error but that was because i was using a random integer generator to make the octals and didn't notice i had 8 and 9 in in there which wouldn't be a valid octal number, duh.