clang_basic.md

C Programming Language

Learning C

• The best way to learn programming is, always, writing your own code!

• Why Code in C Anymore?....Instead of C++

  • C still has a little advantage on the performance and portability.

• CS2022: Introduction to C at Cornell

  • Lecture slides are available.

• learn-c.org free interactive C tutorial

• 30-seconds-of-c

  • Curated collection of useful C Programming tutorials, snippets, and projects that you can understand in 30 seconds or less

Useful Libraries

Performance

• Optimization of Computer Programs in C

  • By Michael Lee. "It focuses on minimizing time spent by the CPU and gives sample source code transformations that often yield improvements. Memory and I/O speed improvements are also discussed."

• Tips for Optimizing C/C++ Code

  • Very practical and useful guides for optimizing C/C++.

• mimalloc - mimalloc is a compact general purpose allocator with excellent performance

  • By Microsoft. mimalloc (pronounced "me-malloc") is a general purpose allocator with excellent performance characteristics. It is a drop-in replacement for malloc and can be used in other programs without code changes.

Numerical

• GSL - GNU Scientific Library

  • The library provides a wide range of mathematical routines such as random number generators, special functions and least-squares fitting. There are over 1000 functions in total with an extensive test suite.
  • The online reference manual can be found here.

• FFTW

  • FFTW is a C subroutine library for computing the discrete Fourier transform (DFT) in one or more dimensions, of arbitrary input size, and of both real and complex data (as well as of even/odd data, i.e. the discrete cosine/sine transforms or DCT/DST).
  • The online manual can be found here

Astronomy Related

• cfitsio - ANSI C routines for reading and writing FITS format data files

Specific Topics

Multiprocessing

GPU Enhancement

Code to Study

• sextractor - Extract catalogs of sources from astronomical images

• psfex - Generate PSF super-tabulated models

• CCL - DESC Core Cosmology Library

  • Also teaches you how to interact with Python.

• Corrfunc - fast correlation functions on the CPU

  • utils are written in C; and wrapped in Python.

On Interacting with Python

• sep - Python and C library for source extraction and photometry
  • Using Cython.
• cosmology - Some code for calculating cosmological distances
  • By Erin Sheldon. Using CPython
• smatch - Code to match points on the sphere using the healpix scheme
  • By Erin Sheldon. Using CPython