Hi Cristian, >How can I take just the real number of that pair?
pmt::car and pmt::cdr give you the first and second element of a pmt::cons. > do you have a reference page of the command? https://gnuradio.org/doc/doxygen/namespacepmt.html#a7ab95721db5cbda1852f13a92eee5362 I must admit that I find PMT not the best-documented piece of software myself. > I understood that I need to send the pair. Is it possible to send just > the real number? As said, you can send /any/ PMT – it's just customary to follow a few common patterns. But sure, you can just as well just send pmt::from_double(your_double). Best regards, Marcus On 27.06.2017 14:16, Cristian Rodríguez wrote: > Hi Marcus. > > Thanks for your message. > > How can I take just the real number of that pair? do you have a > reference page of the command? > I was reading a lot yesterday and my search wasn't well. > > I understood that I need to send the pair. Is it possible to send just > the real number? > > Again, thanks a lot for your time. > > Best regards, > > Cristian > > On Jun 27, 2017 3:48 AM, "Marcus Müller" <marcus.muel...@ettus.com > <mailto:marcus.muel...@ettus.com>> wrote: > > You're explicitly sending a pair (pmt::cons), not a real or > integer number! > > > On 27.06.2017 04:57, Cristian Rodríguez wrote: >> Hi. >> >> Thanks a lot for your time to read. >> >> I read the two links that you shared to me, Marcus. Thanks a lot >> for your help. But i still have a problem. >> >> I've implemented as follows: >> >> * I create, the output, input and the handler: >> >> message_port_register_out(pmt::mp("out_threshold")); >> >> message_port_register_in(pmt::mp("in_threshold")); >> set_msg_handler(pmt::mp("in_threshold"), >> boost::bind(&sync_short_impl::set_msg, this, _1)); >> >> * I create, the next function to handle the inputs >> >> void set_msg(pmt::pmt_t msg) { d_msg= msg; >> dout << "Nueva lectura : " << d_msg << " ninput: " << >> std::endl; >> if (pmt::is_integer(d_msg)) { >> d_threshold = (double) pmt::to_long(d_msg); >> } else if (pmt::is_real(d_msg)) { >> d_threshold = pmt::to_double(d_msg); >> } else { >> // We really expected an integer or a double here, so we don't >> know what to do >> throw std::runtime_error("expected an integer!"); >> } >> >> } >> >> * In the block i linked the input and the output, just to check >> that the function set_msg(), works. >> >> >> Imágenes integradas 3 >> >> * I compile the c++ codes, etc... all that is necessary. >> * I write the output as follows (that's working, i checked that >> with a message debug): >> >> message_port_pub(pmt::mp("out_threshold"), >> pmt::cons(pmt::PMT_NIL, pmt::from_double(d_threshold))); >> >> * When i start the flowgraph, the block put in the output a PMT >> message, after that, as it is linked with the input, the >> message go to the input port. When it is recevied, the >> function set_msg is launched, but the type of the number in >> the PMT is not recognized as double. *Here is my problem, I >> don't understand why it is happening, because the PMT that I >> put in the output is build from a double, then it is >> supposed, the one that i received is too a double. What do >> you think?* >> >> Imágenes integradas 2 >> >> >> Thanks in advance. >> >> >> Best regards, >> >> >> Cristian >> >> 2017-06-26 12:45 GMT-05:00 Marcus Müller >> <marcus.muel...@ettus.com <mailto:marcus.muel...@ettus.com>>: >> >> Hi Cristian, >> >> you need to subscribe a /handler/ to the message port. See: >> >> >> https://wiki.gnuradio.org/index.php/Guided_Tutorial_Programming_Topics#5.3.2_Adding_Message_Passing_to_the_Code >> >> <https://wiki.gnuradio.org/index.php/Guided_Tutorial_Programming_Topics#5.3.2_Adding_Message_Passing_to_the_Code> >> >> It's absolutely up to you what kind of PMT you're publishing >> over a message port, but it's canonical to have a PMT dict >> that maps >> >> pmt::mp("propertyname") -> pmt::whateversuitsyourproperty. >> >> As an example, see what the gr-uhd blocks accept [1] >> >> Best regards, >> >> Marcus >> >> [1] >> https://gnuradio.org/doc/doxygen/page_uhd.html#uhd_command_syntax >> <https://gnuradio.org/doc/doxygen/page_uhd.html#uhd_command_syntax> >> >> On 06/26/2017 07:35 PM, Cristian Rodríguez wrote: >>> Hi all, >>> >>> I'm not sure about how to read and write PMT ports from and >>> to local variables. I'm going to expose what i'm doing, and >>> if someone can help me i would be very greatful. >>> >>> I've created an input and an output of PMT type. >>> >>> message_port_register_in(pmt::pmt_t in_threshold) >>> message_port_register_out(pmt::pmt_t out_threshold) >>> >>> Now i want to read the port, and save the data in a local >>> variable, do operations with that variable, and later write >>> it in the output, >>> >>> I create the variables, >>> >>> double d_threshold; >>> pmt::pmt_t target; >>> >>> *I read it, I don't know how to do it. But I suppose: >>> >>> * >>> message_port_sub(pmt::pmt_t >>> >>> <https://gnuradio.org/doc/doxygen/namespacepmt.html#ab4b70d9293452eb74dd07c670e6811fa> >>> in_threshold,pmt::pmt_t >>> >>> <https://gnuradio.org/doc/doxygen/namespacepmt.html#ab4b70d9293452eb74dd07c670e6811fa> >>> target); >>> d_threshold= pmt::to_double >>> >>> <https://gnuradio.org/doc/doxygen/namespacepmt.html#a0f58166fe9f449249f5de7dc7b3ab754>(target); >>> >>> And, I think i can write it as follows: >>> >>> msg=pmt::from_double >>> >>> <https://gnuradio.org/doc/doxygen/namespacepmt.html#ad20c287c509e8470d03d1c8e97fea12d>(d_threshold); >>> message_port_pub(pmt::pmt_t >>> >>> <https://gnuradio.org/doc/doxygen/namespacepmt.html#ab4b70d9293452eb74dd07c670e6811fa> >>> out_threshold,pmt::pmt_t >>> >>> <https://gnuradio.org/doc/doxygen/namespacepmt.html#ab4b70d9293452eb74dd07c670e6811fa> >>> msg); >>> >>> What do you think, i've seen several examples, and they do >>> this, message_port_pub(pmt::mp("symbols"), >>> pmt::cons(pmt::make_dict(), pmt::init_c32vector(48, symbols))); >>> >>> But I don't understand why it is necessary to use >>> pmt::make_dict(). >>> >>> Thanks in advance. >>> >>> Best regards, >>> >>> Cristian >>> >>> >>> >>> _______________________________________________ >>> Discuss-gnuradio mailing list >>> Discuss-gnuradio@gnu.org <mailto:Discuss-gnuradio@gnu.org> >>> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio >>> <https://lists.gnu.org/mailman/listinfo/discuss-gnuradio> >> >> >> _______________________________________________ >> Discuss-gnuradio mailing list >> Discuss-gnuradio@gnu.org <mailto:Discuss-gnuradio@gnu.org> >> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio >> <https://lists.gnu.org/mailman/listinfo/discuss-gnuradio> >> >> > >
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