Pascale Bou Chahine

Last seen: 3 years ago | Active since 2020

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Solving a least squares problem using QR decomposition
"Given the least squares problem ||b - Ax||_2 = min_{y in R^n} ||b - Ax||_2 where A in R^{mxn} and b in R^m are given, and A is...

3 years ago | 1 answer | 0

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solving a least square problem with an algorithm

3 years ago | 0 answers | 0

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Modifying an algorithm to perform BLAS1 operations
I am asked to modify the following algorithm (LU decomposition of A) to perform BLAS1 operations instead of scalar operations. H...

3 years ago | 0 answers | 0

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Computing number of flops
Let A in R^{nxn}. (a) Compute the number of flops needed to compute A^k using matrix-matrix multiplications. (b) Assuming th...

3 years ago | 0 answers | 0

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Multiplying two square matrices by performing vector operations
function C=multiply(A,B) [n,n] = size(A); [n,n]=size(B); %C=zeros(n,n); for j=1:n for i=1:n C(i,j)= A(i,:).*B(...

3 years ago | 1 answer | 0

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What is the most efficient algorithm for multiplying a square matrix by an upper triangular matrix
If A and B are square matrix, and B is an upper triangular matrix, then what is the most efficient algorithm to calculate C = A ...

3 years ago | 1 answer | 0

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Parallelizing algorithms and finding the number of words each processor needs
Assuming that m = n = p is divisible by 4, and that 4 processors are computing the matrix-matrix multiplication C = AB where A, ...

3 years ago | 0 answers | 0

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Modify an algorithm to perform vector operations by eliminating the inner most for loop
Let A and B be square matrices (both stored column-wise) in R^{nxn} with B an Upper Triangular matrix. Write the MATLAB algorith...

3 years ago | 0 answers | 0

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Computing the outer product (BLAS 2 operation) raised to the power k using the least number of flops
Explain how (xy^T)^k can be computed using the least number of flops, where x, y in R^n are vectors. Then write the correspondin...

3 years ago | 2 answers | 0

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Storing the generated matrices from a for loop into cell arrays and access them later to multiply them altogether
I have to write the corresponding MATLAB algorithm to get the first column of M = (A - x_k*I)(A - x_(k-1)*I)(A - x_1*I), where A...

3 years ago | 1 answer | 0

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Write a MATLAB algorithm takes as input the vector x and computes C rowwise
Say I have a vector x in R^3, such that x = [1 2 3]. I want to form from x, a matrix C = [1 2 3; 3 1 2; 2 3 1]. So, basically, t...

3 years ago | 1 answer | 0

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