Hi all,
I've been trying to create a block that helps me comparing two signals, and
in order to achieve that I want to take a snapshot of one of them to
characterize it in terms of mean and maximum value. The inputs are always
positive and greater than zero. That part of the code goes as follows:
function::work(int noutput_items,
gr_vector_const_void_star &input_items,
gr_vector_void_star &output_items)
{
const float *in = (const float *) input_items[0];
float *first_profile = (float *) output_items[0];
float *second_profile = (float *) output_items[1];
if(!initial_vector_flag){ // run this loop only one time
for (int i = 0; i < nsamples ; ++i) { // why 4096? for values
greater than 4096 in[i] is 0, but why?
std::memcpy(first_profile, in, noutput_items*sizeof(float));
sum_signal += in[i];
if (in[i] == 0) count++;
signal_vector.push_back(in[i]);
}
initial_vector_flag = true;
}
double mean_value = sum_signal / vector_vector.size();
float max = max(signal_vector);
So in this part I bypass the input to the output, but also want to save the
values in a vector from which I calculate the biggest value of the sample
and the mean of the saved realizations. However, I noticed that I can not
deliberately choose the value of nsamples, and that it is only taking 4096
values from the input. Whenever nsamples>4096, the block fills the vector
with 4096 correct values and the rest with zeros (sinking the value of the
mean). I noticed that the number 4096 was correct just by afterwards
counting the values on signal_vector that were different than zero (which
were in every case 4096). From here two questions rise into my mind.
1. Where does the 4096 comes from? it is 2¹², which I don't recall being 12
the size of one datatype that is involved in my function. It is directly a
value from scheduler and always the same?
2. If it is not always the same value, how I am indirectly fixing that
amount of samples? I would like, if possible, to save more samples as it
would reduce the variance of the calculations.
Thank you in advance.
Best Regards,
--
Nicolás Cuervo Benavides
Handy: +49 157 70476855
Electric and Electronic Engineering department.
Electronic Engineering
Universidad Nacional de Colombia
--
Student M.Sc. Information and Communication Technology
Karlsruher Institut für Technologie
Karlsruhe, Baden Würtemberg, Germany
_______________________________________________
Discuss-gnuradio mailing list
Discuss-gnuradio@gnu.org
https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
