Hi, all,

Can anyone tell me which function in Python could I use to generate a

fixed length of 0s and 1s? I know in matlab we could just use

randsrc(x, y, 0:1), while I’ve no idea how to implement it in Python.

Thanks for ur help!

Hi, all,

Can anyone tell me which function in Python could I use to generate a

fixed length of 0s and 1s? I know in matlab we could just use

randsrc(x, y, 0:1), while I’ve no idea how to implement it in Python.

Thanks for ur help!

yufeng wang wrote:

Can anyone tell me which function in Python could I use to generate a

fixed length of 0s and 1s? I know in matlab we could just use

randsrc(x, y, 0:1), while I’ve no idea how to implement it in Python.

Thanks for ur help!

Look at the linear shift feedback register (gr_lfsr_32k_source_s) block.

It should do what you want.

@(^.^)@ Ed

yufeng wang wrote am 2009-02-13 14:34:

Hi, all,

fixed length of 0s and 1s? I know in matlab we could just use

randsrc(x, y, 0:1), while I’ve no idea how to implement it in Python.

Thanks for ur help!

If you want to have random sources in GNU Radio, you can use various

sources, like a noise source or a LSFR source[2].

One method for a fixed length:

import random

length = 10

rand_sequence = random.sample(length/2*[1]+length/2*[0],length)

This first generates a list of 1s and 0s and permutates them. You can

vary the length/2-part to get a not-even-distribution.

Or:

rand_sequence = [x%2 for x in random.sample(xrange(10000000), length)]

These may not be the most efficient or random one, but it should do for

a first shot. For really long sequences yu should construct a sequence

from a random source with multiple invocations, like multiple

random.choice([0,1]) if you need reproducible numbers, or

random.SystemRandom([0,1]) to get good non-reproducible numbers. Read

all about random numbers and Python in [0]

If you are unfamiliar with Python, just read the Python Tutorial[1],

it’s really great.

Patrick

[0] http://docs.python.org/library/random.html

[1] http://docs.python.org/tutorial/

[2] http://www.gnuradio.org/doc/doxygen/group__source.html

–

Engineers motto: cheap, good, fast: choose any two

Patrick S.

Student of Telematik, Techn. University Graz, Austria