search for: dotproduct

Hello, I need to take a dot product of each row of a dataframe and a vector. The number of columns will be dynamic. The way I've been doing it so far is contorted. Is there a better way? dotproduct <- function(dataf, v2) { apply(t(t(as.matrix(a)) * v2),1,sum) #contorted! } df = data.frame(a=c(1,2,3),b=c(4,5,6)) vec = c(4,5) dotproduct(df, vec) thanks, allie

...not be required I tried doing the same to the input arrays of my dot product example but it still doesn't generate packed float or double instructions. Is the loop vectorizer supposed to generate packed float and double instructions? Is this a bug, or am I doing something wrong? Tyler float dotproduct(float *A, float *B, int n) { float sum = 0; for(int i = 0; i < n; ++i) { sum += A[i] * B[i]; } return sum; } clang dotproduct.cpp -O3 -fvectorize -march=atom -S -o - <loop body> .LBB1_1: movss (%rdi), %xmm1 addq $4, %rdi mulss (%rsi), %xmm1...

...g the same to the input arrays of my dot product example but it still doesn’t generate packed float or double instructions. > > Is the loop vectorizer supposed to generate packed float and double instructions? Is this a bug, or am I doing something wrong? > > Tyler > > float dotproduct(float *A, float *B, int n) { > float sum = 0; > for(int i = 0; i < n; ++i) { > sum += A[i] * B[i]; > } > return sum; > } > > clang dotproduct.cpp -O3 -fvectorize -march=atom -S -o - > > <loop body> > .LBB1_1: > movss (%rdi), %xm...

...not be required I tried doing the same to the input arrays of my dot product example but it still doesn't generate packed float or double instructions. Is the loop vectorizer supposed to generate packed float and double instructions? Is this a bug, or am I doing something wrong? Tyler float dotproduct(float *A, float *B, int n) { float sum = 0; for(int i = 0; i < n; ++i) { sum += A[i] * B[i]; } return sum; } clang dotproduct.cpp -O3 -fvectorize -march=atom -S -o - <loop body> .LBB1_1: movss (%rdi), %xmm1 addq $4, %rdi mulss (%rsi), %xmm1...

I want to compare two documents in the index (i.e. retrieve the cosine similarity/score between two documents term-vector''s). Is this possible using the standard Ferret functionality? Thanks in advance, Jeroen Bulters -- Posted via http://www.ruby-forum.com/.

...ple vector floats are usually faster in the scalar units. The add across and transfer to scalar is just too expensive. Its generally only worthwhile if the data starts and ends in the vector units, and it is inlined so that latencies can be covered with other work. e.g: inline vector float DotProduct( vector float a, vector float b ) { a = vec_madd( a, b, (vector float) vec_splat_u32(0) ) ; a = vec_add( a, vec_sld( a, a, 8 ) ); a = vec_add( a, vec_sld( a, a, 4 ) ); return a; } Ian ----------------------------------...

I intend to finish my Vorbis document on Monday so I will leave it over the weekend to see if there are any more modifications suggested. Although the document will be internal I will put a copy of the final version at the same address - I know firsthand how annoying it is to find loads of dead links when trying to find background info on Vorbis (I know google has probably already got a link

So we ran the code on a Windows XP based Atholon XP system and the xmm registers work just fine so it appears that Windows 2000 and below does not support them. We agree on not supporting the non-FP version, however the run time flags need to be settable with a non FP SSE mode so that exceptions are avoided. I thus propose a set of defines like this instead of the ones in our initial patch: