Hi Samuel,
I have checked 2d FFT for the same data in MATLAB and there the imaginary are non zero. So its not due to property of DFT. Regards, Koyel Das Senior – Product Engineer Vehere | Proactive Communications Intelligence & Cyber Defence M: +919051132173 | T: +91 33 40545454 | F: +91 33 40545455 | W: www.vehere.com<http://www.vehere.com/> [unnamed]<https://www.linkedin.com/company/vehere-interactive-p-ltd> [unnamed (1)] <https://twitter.com/VehereIndia> [unnamed (2)] <https://www.facebook.com/VehereIndia/> Vehere is the proud recipient of the Fastest Growing Technology Company Awards in India & Asia since 2012! The content of this e-mail is confidential and intended solely for the use of the addressee. The text of this email (including any attachments) may contain information, which is proprietary and/or confidential or privileged in nature belonging to Vehere Interactive Pvt Ltd and/or its associates/ group companies/ subsidiaries. If you are not the addressee, or the person responsible for delivering it to the addressee, any disclosure, copying, distribution or any action taken or omitted to be taken in reliance on it is prohibited and may be unlawful. If you have received this e-mail in error, please notify the sender and remove this communication entirely from your system. The recipient acknowledges that no guarantee or any warranty is given as to completeness and accuracy of the content of the email. The recipient further acknowledges that the views contained in the email message are those of the sender and may not necessarily reflect those of Vehere Interactive Pvt Ltd. Before opening and accessing the attachment please check and scan for virus. WARNING: Computer viruses can be transmitted via email. The recipient should check this email and any attachments for the presence of viruses. The company accepts no liability for any damage caused by any virus transmitted by this email. ________________________________ From: Samuel Prager <spra...@usc.edu> Sent: Friday, May 17, 2019 11:01:00 AM To: Koyel Das (Vehere) Cc: Marcus D. Leech via USRP-users Subject: Re: [USRP-users] problem with fftw_plan_dft_2d >From a cursory glance it looks like you are creating (hermetian) symmetry in >your data with phy [whatever][whatever] I would suggest reviewing the properties of the discrete Fourier transform. On May 16, 2019, 9:11 PM -0700, Koyel Das (Vehere) via USRP-users <usrp-users@lists.ettus.com>, wrote: Hi Marcus, I emailed to f...@fftw.org<mailto:f...@fftw.org> but got no response so I thought some USRP users might also be using this library and hence I may get a response. That is why. Regards, Koyel Das Senior – Product Engineer Vehere | Proactive Communications Intelligence & Cyber Defence M: +919051132173 | T: +91 33 40545454 | F: +91 33 40545455 | W: www.vehere.com<https://urldefense.proofpoint.com/v2/url?u=http-3A__www.vehere.com_&d=DwMF-g&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=opIuWAKmywF059tAs2i3Pg&m=-qnV50ad393nJaYxBSJrDtf-lbPbX2g22z_VrjcI6hE&s=iZCiVpP9F-vIO8i9kvKmEOxr0v4DWyZhNboftC1fFzw&e=> [unnamed]<https://urldefense.proofpoint.com/v2/url?u=https-3A__www.linkedin.com_company_vehere-2Dinteractive-2Dp-2Dltd&d=DwMF-g&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=opIuWAKmywF059tAs2i3Pg&m=-qnV50ad393nJaYxBSJrDtf-lbPbX2g22z_VrjcI6hE&s=vVjJUZ9f5_1YyXYaaEUe2Cd65eWLCqQe_tjnLnG16es&e=> [unnamed (1)] <https://urldefense.proofpoint.com/v2/url?u=https-3A__twitter.com_VehereIndia&d=DwMF-g&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=opIuWAKmywF059tAs2i3Pg&m=-qnV50ad393nJaYxBSJrDtf-lbPbX2g22z_VrjcI6hE&s=y0xzq_cb11Rg3_cRs8avpT0yRw9KdVe_PUcsUx0IaGc&e=> [unnamed (2)] <https://urldefense.proofpoint.com/v2/url?u=https-3A__www.facebook.com_VehereIndia_&d=DwMF-g&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=opIuWAKmywF059tAs2i3Pg&m=-qnV50ad393nJaYxBSJrDtf-lbPbX2g22z_VrjcI6hE&s=iG-fGGkhjzHA7j39KWWV_Btvg0kbAysoz3t3A3IAW8g&e=> Vehere is the proud recipient of the Fastest Growing Technology Company Awards in India & Asia since 2012! The content of this e-mail is confidential and intended solely for the use of the addressee. The text of this email (including any attachments) may contain information, which is proprietary and/or confidential or privileged in nature belonging to Vehere Interactive Pvt Ltd and/or its associates/ group companies/ subsidiaries. If you are not the addressee, or the person responsible for delivering it to the addressee, any disclosure, copying, distribution or any action taken or omitted to be taken in reliance on it is prohibited and may be unlawful. If you have received this e-mail in error, please notify the sender and remove this communication entirely from your system. The recipient acknowledges that no guarantee or any warranty is given as to completeness and accuracy of the content of the email. The recipient further acknowledges that the views contained in the email message are those of the sender and may not necessarily reflect those of Vehere Interactive Pvt Ltd. Before opening and accessing the attachment please check and scan for virus. WARNING: Computer viruses can be transmitted via email. The recipient should check this email and any attachments for the presence of viruses. The company accepts no liability for any damage caused by any virus transmitted by this email. ________________________________ From: USRP-users <usrp-users-boun...@lists.ettus.com> on behalf of Marcus D. Leech via USRP-users <usrp-users@lists.ettus.com> Sent: Friday, May 17, 2019 9:27:34 AM To: usrp-users@lists.ettus.com Subject: Re: [USRP-users] problem with fftw_plan_dft_2d On 05/16/2019 11:52 PM, Koyel Das (Vehere) via USRP-users wrote: Hi, Following is a snapshot of my code using fftw_plan_dft_2d. I am getting all zeros in the imaginary part of fft (in the printf command of the following code:last line). The real part is correct.Could you please tell where am I going wrong? fftw_complex *imageOutputPlane=VDDSAlgorithm::imageOutPlane; fftw_complex *imageInputPlane=VDDSAlgorithm::imageInputPlane; unsigned char*imageData=VDDSAlgorithm::imageData; unsigned char*imageDataFinal=VDDSAlgorithm::imageDataFinal; memset(imageInputPlane,0x0,IMAGE_DIMENSION*IMAGE_DIMENSION*sizeof(fftw_complex)); memset(imageOutputPlane,0x0,IMAGE_DIMENSION*IMAGE_DIMENSION*sizeof(fftw_complex)); memset(imageData,0x0,IMAGE_DIMENSION*IMAGE_DIMENSION); for(size_t count=0;count<TOTAL_BASE_LINE;count++){ imageInputPlane[(int)round(IMAGE_DIMENSION/2+diffX[count])*IMAGE_DIMENSION+(int)round(IMAGE_DIMENSION/2-diffY[count])][0]=phy[count][0]; imageInputPlane[(int)round(IMAGE_DIMENSION/2+diffX[count])*IMAGE_DIMENSION+(int)round(IMAGE_DIMENSION/2-diffY[count])][1]=-(phy[count][1]); imageInputPlane[(int)round(IMAGE_DIMENSION/2-diffX[count])*IMAGE_DIMENSION+(int)round(IMAGE_DIMENSION/2+diffY[count])][0]=phy[count][0]; imageInputPlane[(int)round(IMAGE_DIMENSION/2-diffX[count])*IMAGE_DIMENSION+(int)round(IMAGE_DIMENSION/2+diffY[count])][1]=phy[count][1]; } fftLock.lock(); fftw_plan planeX=fftw_plan_dft_2d(IMAGE_DIMENSION,IMAGE_DIMENSION, imageInputPlane, imageOutputPlane, FFTW_FORWARD, FFTW_ESTIMATE); fftw_execute(planeX); fftw_destroy_plan(planeX); fftLock.unlock(); double max=0; for(size_t row=0;row<IMAGE_DIMENSION;row++){ for(size_t col=0;col<IMAGE_DIMENSION;col++){ if(col==0)printf("\n"); if(col<100){ printf("(%lf,%lf)",imageOutputPlane[row*IMAGE_DIMENSION+col][0],imageOutputPlane[row*IMAGE_DIMENSION+col][1]); } } } Regards, Koyel Das Senior – Product Engineer Vehere | Proactive Communications Intelligence & Cyber Defence M: +919051132173 | T: +91 33 40545454 | F: +91 33 40545455 | W: www.vehere.com<https://urldefense.proofpoint.com/v2/url?u=http-3A__www.vehere.com_&d=DwMF-g&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=opIuWAKmywF059tAs2i3Pg&m=-qnV50ad393nJaYxBSJrDtf-lbPbX2g22z_VrjcI6hE&s=iZCiVpP9F-vIO8i9kvKmEOxr0v4DWyZhNboftC1fFzw&e=> I'm having a hard time seeing how this is related to UHD and USRPs. There's probably a support forum for FFTW out there that would be more helpful than here. _______________________________________________ USRP-users mailing list USRP-users@lists.ettus.com https://urldefense.proofpoint.com/v2/url?u=http-3A__lists.ettus.com_mailman_listinfo_usrp-2Dusers-5Flists.ettus.com&d=DwICAg&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=opIuWAKmywF059tAs2i3Pg&m=-qnV50ad393nJaYxBSJrDtf-lbPbX2g22z_VrjcI6hE&s=v3PIq2NHPrK8xhyDNyIJd7OgWYtaTPicFlzxjtAZTJU&e=
_______________________________________________ USRP-users mailing list USRP-users@lists.ettus.com http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com
