Hi Sumit, > I will try out the method you suggested. I have a second question > regarding FFT. Is there any example in VCL to compute a 2D FFT? Can you > share some pointers to that?
There are tests in tests/src which you can have a look at. > Also, when computing the FFT do we have to ensure that the data is > dyadic (or to be zero-padded to make it dyadic)? You can pass any data size, but you will only see good performance with a power of 2. Best regards, Karli > > ------------------------------------------------------------------------ > *From:* Karl Rupp <r...@iue.tuwien.ac.at> > *To:* Sumit Kumar <dost_4_e...@yahoo.com>; viennacl-devel > <viennacl-devel@lists.sourceforge.net> > *Sent:* Tuesday, March 1, 2016 7:24 PM > *Subject:* Re: [ViennaCL-devel] Examples of importing raw buffers > > Hi Sumit, > > sorry, I overlooked this email in my mailers threaded view. > > > > I have a question here: > > a.) Suppose I have three raw buffers (let us assume float); I would like > > to do something like this: > > v = (I- a) / (W-a+EPS), where I, W and a are the three buffers and EPS > > is a scalar to prevent a division by 0 operation. > > > > b.) I know I can wrap these buffers to Eigen matrices and then copy them > > to VCL using the API's. However, is there a way to do this step in a 1 > > shot operation without acutally wrapping them to Eigen? Essentially, > > this is an element-wise subtraction and a division happening > > simultaneously, and both are embarrassingly parallel operations. > > You can just use vector operations. something like > viennacl::vector<T> eps = viennacl::scalar_vector<T>(N, EPS); > v = viennacl::linalg::element_div(I - a, W - a + eps); > should do it. > > > > > The second question I have is w.r.t OpenCL SDK selection: > > a.) Let us assume I have an Intel CPU with an AMD GPU. VCL supports > > OpenCL backends for both CPU and GPU and I have the liberty to choose > > any device and any backend. > > b.) If I were to have this combination, how would I go about building > > the code? Do I need to download SDK's for both combinations (so that I > > can distribute both binaries?). I had posed this question on the OpenCL > > users group in LinkedIn but got no response so thought of asking you > > instead. > > The Intel OpenCL SDK will only support CPUs. The only way to get access > to the AMD GPU is to install the AMD GPU driver (formerly this was > bundled in the AMD APP SDK). You have to query the OpenCL platform > properties (e.g. vendor name) at runtime to select the correct platform. > In ViennaCL you can, for example, check the id() of the platform, which > is usually the same for a given vendor across different machines. > > > Best regards, > Karli > > > > ------------------------------------------------------------------------------ Site24x7 APM Insight: Get Deep Visibility into Application Performance APM + Mobile APM + RUM: Monitor 3 App instances at just $35/Month Monitor end-to-end web transactions and take corrective actions now Troubleshoot faster and improve end-user experience. Signup Now! http://pubads.g.doubleclick.net/gampad/clk?id=272487151&iu=/4140 _______________________________________________ ViennaCL-devel mailing list ViennaCL-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/viennacl-devel
