JULIA_OPENMP
Julia Set Image using OpenMP


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.

Licensing:

The computer code and data files described and made available on this web page are distributed under the GNU LGPL license.

Languages:

JULIA_OPENMP is available in a C version.

Related Data and Programs:

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.

Reference:

  1. Heinz-Otto Peitgen, Hartmut Juergens, Dietmar Saupe,
    Chaos and Fractals - New Frontiers in Science,
    Springer, 1992,
    ISBN: 0-387-20229-3,
    LC: Q172.5.C45.P45.

Source Code:

You can go up one level to the C source codes.


Last revised on 14 March 2017.