George,
What is happening is that when you try to change the variable Python is
interpreting that as a local variable and has no value yet for the equation you
are attempting. I believe could use:
global vv[0] += v[0]
(Research the Python global keyword)
However, in the GNURadio universe I really think you may be better off using
self.v instead.
Tim
On Thursday, January 14, 2021, 11:42:46 AM EST, George Edwards
<gedwards....@gmail.com> wrote:
Hell Tim and Jeff,
Problem, so when I make v global in my_init() method and use it is the work()
method, it works good if I do not try to change the values in the vector v,
let's say v came down as v = np.array([1.0 , 1.0 , 1.0]). If I try to change
the values say v[0] += v[0], etc. the program breaks with the message local
variable v changes before assignment. I thought it was global and already
assigned.
Thanks for your help.
George
On Thu, Jan 14, 2021 at 9:17 AM George Edwards <gedwards....@gmail.com> wrote:
Hi Tim and Jeff,
Thanks for your help and insights. Being new to Python, I was looking at some
Python videos and found my solution, I will make the numpy parameter vectors in
the my_init() method "global" and that should solve the problem.
Thank you!
Regards,George
On Thu, Jan 14, 2021 at 9:57 AM Tim Huggins <huggins.timo...@yahoo.com> wrote:
George,
"My understanding is the self.x, etc. is used to initialize param arguments in
the def __init__() method and in my case, the only argument in this method is
start"
This is not correct, you can add a self.v in there so it looks like:
def __init__(self, start = True): # only default arguments here
gr.sync_block.__init__(
self,
name='text', # will show up in GRC
in_sig=[()],
out_sig=[()]
)
# if an attribute with the same name as a parameter is found,
# a callback is registered (properties work, too).
self.start = start
self.v = self.my_init() #or whatever you want the initial value to be
Tim
On Thursday, January 14, 2021, 10:38:36 AM EST, George Edwards
<gedwards....@gmail.com> wrote:
Hi Jeff,
So I am new to Python programming, so some of the nuances I am not up on yet.
My understanding is the self.x, etc. is used to initialize param arguments in
the def __init__() method and in my case, the only argument in this method is
start, there is no v for me to use self.v = v. v is used the work() and
my_init() methods. At program startup work() calls my_init() method to get the
initial values for the numpy array v (my_init() function will be called once
only at startup when self.start is True). After initialization and v is passed
back to the work(), the values in the numpy array v inside work will change on
a sample to sample computation basis. My problem is how do I assign v its
initial seed value at start up. If my program was simple with only one
parameter v, I would initialize it inside the work() method, however, I have a
bunch of other vector variables to initialize which is why I want to initialize
all parameters inside a my_init() method that work() calls at startup.
Thanks for the help.
George
On Thu, Jan 14, 2021 at 8:14 AM Jeff Long <willco...@gmail.com> wrote:
You are already initializing self.start in exactly the same way you should be
initializing self.v, right?
On Wed, Jan 13, 2021 at 10:46 PM George Edwards <gedwards....@gmail.com> wrote:
Hi Jeff,
Thanks for your answer. You are right, it crashes on the second call.
So how do I write the program to initialize a bunch of vectors in a "method
strictly for initialization" when it first starts running? If this cannot be
done, then I guess the only solution is to initialize them in the work() method
even though it would make the work() method bulky?
Thanks again for your help.
Regards,George
On Wed, Jan 13, 2021 at 8:12 PM Jeff Long <willco...@gmail.com> wrote:
'v' is a local variable in work(). It is probably crashing on the second call,
where my_init() is not called, and thus there is no 'v'.
On Wed, Jan 13, 2021 at 7:38 PM George Edwards <gedwards....@gmail.com> wrote:
Hello,
I am using a Gnuradio Python Block in my GRC signal processing and am having
problems initializing my parameters. My system has a number of vector
parameters to be initialized at startup. I will provide the gist of my goal in
a scaled down version of my work. 1. In the def __init__(self, start = True)
method, "start" is the parameter that will be used in the program to run the
initialization process and is set as follows: self.start = start 2. In
the work(self, input_items, output_items) method, I have the following at the
start of the method: if self.start == True: v =
self.my_init() # go initialize all vectors
output_items[0][:] = in0*v[0] + in1*v[1] + in2*v[2] #computation
using v # with 3-inputs to
the block
3. In the my_init(self) method I have: self.start = False #
set start to False v = np.array([1., 2., 3.]) #hypothetical to make
this simple return v
When I run the GRC model, it tells me that "v" is referenced before assignment.
I am confused because I thought that the method my_init() would have been
called before the computation and would return the values for "v". On the other
hand if I do the assignment in the work(...) method as v = np.array([1., 2.,
3.]), it works perfectly.Question: Why was the my_init() method not called
properly to get the values for the numpy array v?
Thanks for the help!
Regards,George
