How can we convert negative double value to binary value in matlab?

I'm the student of UCSY.I research for audio scrambling. In my research, I need to scarmble audio data with key using bit wise xor.Now,I have difficulties to convert negative float value to binary value to scramble. Please, anyone can help me?? I would be grateful if someone help me in this matter.

[KALYAN ACHARJYA]

No inbuilt function. "float2bin" user defined function you may search.

[Su Latt Sandi]

Thank for your answer:)

[Rik]

How would you want to convert values to binary? For positive integers this is obvious (and you can use the built in dec2bin), but for all other values it isn't. double and single are already floats, and have a binary representation, but I don't see how that would benefit you for XOR. If you describe what shape the output should have, we can help you.

[Su Latt Sandi]

I used "num2bin(q,x)" commend.But now, I can't xor with audio coefficients and key because dimension is different. I used "scramble=bitxor(c,k)" where c is coefficents(binary values) and k is key(binary value). The problem is c has 26656-row 64-column and k has 1-row 64-column. I can't xor and I don't know how can i get scramble value.

[Su Latt Sandi]

Hi Sir, please find attachment

[Walter Roberson]

num2bin() is for Fixed Point Objects, not for general numbers.

num2bin returns characters, so subtract '0' (the character for the digit 0) to get the numeric values.

Answer 1

[Walter Roberson]

If you are reading the audio data from a file, I recommend that you add the 'native' option. That would usually result in the data being read in as integer, which you can then manipulate.

Otherwise, easiest is probably to typecast() the floating to integer form.

Answer 2

[Matt J]

Use BITGET, for example,

>> bitget(-25,1:8,'int8')

ans =

       1     1     1     0     0     1     1     1

[Walter Roberson]

That only works for values that are integers.

You can experiment with

bitget(typecast(-25.2, 'uint64'), 1:8)

but beware that the byte order might not be what you are expecting.