# Recent bit of writing

The only thing I could manage so far, something related to the new GRA.

https://www.arc.vt.edu/2018/08/new-arc-cluster-huckleberry/

# Run SPEC CPU2017 benchmarks through any Pintool

We developed a cache model for prefetching for our computer architecture course. We had to run address traces for a real application through the model to see if the prefetcher worked. These addresses traces were generated with the Pintool pinatrace on SPEC CPU2017 benchmark software. Detailed here is a short overview of an easy way to use Pintool with SPEC CPU2017 benchmarking suite.

# The Next SoC Design

This was my paper for a Design of Systems on Chip course.

soc-design

# Doubly Compressed Sparse Columns

Code here and presentation here : dcsc_presentation.

# Compressed Storage Rows/Columns Format

Here is a presentation I made to explain how CSR works step-by-step. And the code here.

csr_beamer

# Hermitian Operators and Commutation

According to quantum postulates, every physical property (position, momentum, energy from classical physics) has a quantum mechanical operator. We saw how linear operators work in this post on operators and some stuff in this post.Read More »

# Projection Operators, Norm, Resolution of the Identity

We left off at this equation in the last post.

$|\psi><\psi| = \int \psi(x) \psi^*(x) = \hat{P_{\psi}}$

# Operators/functions and functionals

A linear operator is of the form $A [f(x) + g(x)] \implies Af(x) + Ag(x)$. Assume operator $\dfrac{d}{dx}$ operating on polynomial $f(x) = x^2 + x$ which is a function of $x$. Hence, $\dfrac{d}{dx} f(x) = \dfrac{d}{dx} (x^2 + x) = \dfrac{d}{dx} x^2 + \dfrac{d}{dx}x = 2x + 1$. We’ve seen this before. The significance of this example is that the answer is still a function of x.

Electronic structure theory deals in tensor quantities. Matrices are a special type of tensor, and matrix multiplication is a special type of tensor contraction. In the practical implementation of coupled cluster theory, we store $\hat{T}_{2}$ amplitudes $t^{cd}_{ij}$ are stored in matrix form where we use compound row and col indices ij and cd respectively. This storage scheme is often called a supermatrix.