Recent content by SpiffyEh

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    Help with cblas_dgemm matrix multiplication

    Thanks for the help, I appreciate you spending time on trying to figure this out. I ended up figuring out that the pos matrix needed to be translated so the second parameter was CblasTrans and I needed to make tempPos larger and it worked.
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    Help with cblas_dgemm matrix multiplication

    all of the arrays i said the dimensions for are in row major or are supposed to be. I can't change the pos array dimensions or the rest of the program will break. It's written by someone else as a simulation and is pretty long, I'm just adding averages and a couple other things to it. I can...
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    Help with cblas_dgemm matrix multiplication

    I understand what the parameters mean. I just don't see what I'm doing wrong. I have checked all of the meanings multiple times and the values I'm passing. the mass matrix is n (303) x 1 pos is n(303) x NDIM (3) tempPos is NDIM x 1 tempMass is nlocal(300) x 1 mass_avg is 1x1 pos_avg is...
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    Help with cblas_dgemm matrix multiplication

    I'm having problems running cblas_dgemm on a matix matrix multiplication. I have the following matricies double * mass = new double[n]; double (* pos)[NDIM] = new double[n][NDIM]; double tempPos[NDIM]; double tempMass[nlocal]; double mass_avg[1]; double pos_avg[NDIM]...
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    How many cache misses occur when performing matrix multiplication?

    Yeah... I ended up doing that. Lets say block 0,0 of A includes a00...a09 and a00..a99 (the whole 10x10 square) block 0,0 of B includes b00...b09 and b00...99 same for block c.. so basically the r,c notation represents each 10x10 block in a matrix For block 0,0 in a * block 0,0 in b...
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    How many cache misses occur when performing matrix multiplication?

    oh! That makes so much more sense! Thank you! You assumed correctly, writes do not affect the data cache. I'm pretty sure I figured this one out but now I'm having issues with part b which involves blocking. (b). If matrices are partitioned into block matrices with each block being a 10...
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    How many cache misses occur when performing matrix multiplication?

    Homework Statement Suppose your data cache has 30 lines and each line can hold 10 doubles. You are performing a matrix-matrix multiplication (C=C+A*B) with square matrices of size 1000 and 10 respectively. Assume data caches are only used to cache matrix elements which are doubles. The cache...
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    Calculating speedup given rates and execution time percentage

    Homework Statement a) If the new floating-point speeds up floating-point operations by, on average, 2x, the floating-point operations take 20% of the original program execution time, what is the overall speedup(ignoring the penalty to any other instruction)? b) Now assume that speeding up...
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    Computer architecture power savings question

    Homework Statement Server farms such as Google and Yahoo! provide enough compute capacity for the highest request rate of the day. Imagine that most of the time these servers operate at only 60% capacity. Assume further that the power does not scale linearly with the load; that is, when the...
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    Understanding the Proof of x mod pq = y mod pq for Distinct Primes p and q

    Is there another way to prove this without LCM?
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    Proving X^(k*p-1)+1)mod p = x mod p

    Can anyone help with this? I really need to understand how it works
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    How to do the extended euclidean algorithm

    I still don't understand it. I need someone to literally walk me through it so that I understand each step. I get what the algorithm is for but I don't understand that example I posted. So the inverse is 67 in this case?
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    How to do the extended euclidean algorithm

    Here's the definition I have: Extended Euclidean algorithm Takes a and b Computes r, s, t such that r=gcd(a, b) and, sa + tb = r (only the last two terms in each of these sequences at any point in the algorithm) Corollary. Suppose gcd(r0, r1)=1. Then r_1-1 mod r_0=t_m mod r_0. The...
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    Understanding the Proof of x mod pq = y mod pq for Distinct Primes p and q

    Oh ok. That makes more sense. I still don't understand how the LCM comes in but it's starting to come together some more. Thanks!
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    Proving X^(k*p-1)+1)mod p = x mod p

    Homework Statement Prove that x^(k(p–1)+1) mod p = x mod p for all primes p and integer k ≥ 0. Hint: Use Fermat’s Little theorem and induction on k. Homework Equations I understand that fermat's little theorm is: Let p be prime, and b e Z_p. Then b^p = b (mod p). The Attempt at...
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