JULIA_OPENMP is a C program which produces an image of a Julia set, using OpenMP to carry out the computation in parallel.
Suppose we have a function f(z) defined for any complex number z. Suppose that we repeatedly carry out the iteration z <== f(z). It's natural to assume that the sequence of z values will blow up in magnitude; however it's possible that for some starting values z, the sequence will stay small. We call such points the Julia set for f().
A simple class of test functions has the form f(z)=z^2+c, and some interesting values of the complex number c include 0.4+0.6i, 0.285+0.01i, and 0.7269+0.1889i. For our experiment, we will use c=-0.8+0.156i$. We will only look at points in the rectangle [-1.5,+1.5]x[-1.5,+1.5]. We will pick a 1000x1000 grid in this rectangle, and for each z{i,j} we will iterate 200 times. If the norm of the iterates stays below 1,000, we will consider that it is a member of the Julia set. So our result will essentially be a 1000x1000 array of 0's (not in the set) and 1's (in the set).
Every candidate point can be checked independently. Therefore, determining the stucture of a Julia set is a good candidate for a parallel computation.
The computer code and data files described and made available on this web page are distributed under the GNU LGPL license.
JULIA_OPENMP is available in a C version.
DIJKSTRA_OPENMP, a C program which uses OpenMP to parallelize a simple example of Dijkstra's minimum distance algorithm for graphs.
FFT_OPENMP, a C program which demonstrates the computation of a Fast Fourier Transform in parallel, using OpenMP.
FUNCTIONS_OPENMP, a C program which demonstrates the behavior of a few of the OpenMP library functions.
HEATED_PLATE_OPENMP, a C program which solves the steady (time independent) heat equation in a 2D rectangular region, using OpenMP to run in parallel.
HELLO_OPENMP, a C program which prints out "Hello, world!" using the OpenMP parallel programming environment.
IMAGE_DENOISE_OPENMP, a C library which applies simple filtering techniques to remove noise from an image, carrying out the operation in parallel using OpenMP.
JACOBI_OPENMP, a C program which illustrates the use of the OpenMP application program interface to parallelize a Jacobi iteration solving A*x=b.
JULIA, a C program which generates a TGA or TARGA graphics file of a Julia set.
MANDELBROT_OPENMP, a C program which generates an ASCII Portable Pixel Map (PPM) image of the Mandelbrot set, using OpenMP for parallel execution.
MD_OPENMP, a C program which carries out a molecular dynamics simulation in parallel, using OpenMP.
MULTITASK_OPENMP, a C program which demonstrates how to "multitask", that is, to execute several unrelated and distinct tasks simultaneously, using OpenMP for parallel execution.
MXM_OPENMP, a C program which computes a dense matrix product C=A*B, using OpenMP for parallel execution.
MXV_OPENMP, a C program which computes a dense matrix-vector product b=A*x, using OpenMP for parallel execution.
OPENMP, C programs which illustrate the use of OpenMP.
OPENMP_RCC, C programs which illustrate how a C program, using OpenMP, can be compiled and run in batch mode on the FSU High Performance Computing (HPC) cluster operated by the Research Computing Center (RCC).
POISSON_OPENMP, a C program which computes an approximate solution to the Poisson equation in a rectangle, using the Jacobi iteration to solve the linear system, and OpenMP to carry out the Jacobi iteration in parallel.
PRIME_OPENMP, a C program which counts the number of primes between 1 and N, using OpenMP for parallel execution.
QUAD_OPENMP, a C program which approximates an integral using a quadrature rule, and carries out the computation in parallel using OpenMP.
QUAD2_OPENMP, a C program which approximates a multidimensional integral using a quadrature rule. The quadrature computation is done with OpenMP.
QUAD2D_OPENMP, a C program which estimates an integral over a 2D rectangular domain by using an averaging technique, and uses OpenMP to carry out the calculation in parallel.
RANDOM_OPENMP, a C program which illustrates how a parallel program using OpenMP can generate multiple distinct streams of random numbers.
SATISFY_OPENMP, a C program which demonstrates, for a particular circuit, an exhaustive search for solutions of the circuit satisfiability problem, using OpenMP for parallel execution.
SCHEDULE_OPENMP, a C program which demonstrates the default, static, and dynamic methods of "scheduling" loop iterations in OpenMP to avoid work imbalance.
SGEFA_OPENMP, a C program which reimplements the SGEFA/SGESL linear algebra routines from LINPACK for use with OpenMP.
SUPERLU_OPENMP, C programs which illustrate the use of the SUPERLU_OPENMP library, a version of SUPERLU compiled with the OpenMP parallel programming interface, for the fast direct solution of large sparse systems of linear equations.
ZIGGURAT_OPENMP, a C program which demonstrates how the ZIGGURAT library can be used to generate random numbers in an OpenMP parallel program.
You can go up one level to the C source codes.