Hello Marcus, I realize this is a couple years later but I am attempting to do the same type of arbitrary ratio block, where samples above a threshold are passed and samples below that threshold are dropped.
When I tried to subclass gr.block (as below, and in this tutorial from 2014 <https://github.com/guruofquality/grextras/wiki/Blocks-Coding-Guide#arbitrary-ratio-block> ) in an embedded Python block, GRC threw an error saying gr.block could not be found. Does this method still work, or is there an updated method with basic_block to implement arbitrary ratio blocks in Python? Greetings from Menlo Park, CA, Zach Marcus Müller-3 wrote > Hi Bob, > > I think you've introduced the "j" variable to keep count of how many > items you're going to produce, but then just tell the scheduler you've > produced as many items as he offered you to do. Replace > self.produce(0,len(out0)) > by > self.produce(0,j). > Also, you consume ninput_items every for loop iteration, so > ninput_items^2 per work run. That's not right; do it only once, after > the loop. > > Greetings, > > Marcus > > On 12/24/2014 12:21 PM, bob wole wrote: >> Hi list, >> >> I am writing a custom python block that should take complex input, >> check magnitude of incoming samples and if the magnitude is greater >> than a threshold value, the block should pass that sample otherwise >> the block just drop the samples. As this is an arbitrary ratio block I >> derived it from gr.block and set_auto_consume(False). >> >> However I get intermittent zeros in output stream of my custom block. >> Below is the code >> >> from gnuradio import gr >> import gnuradio.extras >> import math >> import numpy as np >> >> >> class sdr_pass_valid(gr.block): >> """ >> """ >> def __init__(self,threshold): >> gr.block.__init__( >> self, >> name = "VALID", >> in_sig = [np.complex64], >> out_sig = [np.complex64], >> ) >> self.set_auto_consume(False) >> >> self.threshold = threshold >> def forecast (self,noutput_items,ninput_items_required): >> for i in range(len(ninput_items_required)): >> ninput_items_required[i] = noutput_items >> >> def work(self, input_items, output_items): >> >> in0 = input_items[0][:len(output_items[0])] >> out0= output_items[0] >> nread = self.nitems_read(0) #number of items read on port 0 >> ninput_items = len(in0) >> j=0 >> for i in range(0,ninput_items): >> if np.absolute(in0[i]) >= self.threshold : >> out0[j] = in0[i] >> j = j + 1 >> self.consume(0,ninput_items) >> self.produce(0,len(out0)) >> return 0 >> >> >> -- >> Bob >> >> >> _______________________________________________ >> Discuss-gnuradio mailing list >> > Discuss-gnuradio@ >> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio > > > _______________________________________________ > Discuss-gnuradio mailing list > Discuss-gnuradio@ > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio -- View this message in context: http://gnuradio.4.n7.nabble.com/Python-block-help-tp51706p64046.html Sent from the GnuRadio mailing list archive at Nabble.com. _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
