File:Conchospiral.svg

#include <omp.h>
#include <stdio.h>
#include <math.h>
#include <plplot/plplot.h>

#define        NUM_PTS        500
#define        THETA0    M_PI
  
int main (void)
{
    char txtBuffer[30];
    PLFLT *X=NULL, *Y=NULL, *Z=NULL;
    X = (PLFLT*) malloc(NUM_PTS * sizeof(PLFLT*));
    Y = (PLFLT*) malloc(NUM_PTS * sizeof(PLFLT*));
    Z = (PLFLT*) malloc(NUM_PTS * sizeof(PLFLT*));
    if(X == NULL || Y == NULL)
    {perror("Unable to allocate memory space!"); exit(-1);}
   
    plstart("wxwidgets",1,1);
    plscol0(0, 255, 255, 255);
    plscol0(15, 0, 0, 0);
    plcol(15);
   
    unsigned int count=0;
    float temp, theta=-THETA0;
    int col = 1;
    float xmin=0.f, xmax=0.f, ymin=0.f, ymax = 0.f, zmin=0.f, zmax = 0.f;
    const float mu = 1.07, a = 1., c = 1.1;
    #pragma omp for
    for(count = 0; count < NUM_PTS; count++)
    {
        temp = pow(mu,theta);
        X[count] = temp * a * cos(theta);
        Y[count] = temp * a * sin(theta);
        Z[count] = temp * c;
        xmin = (xmin < X[count]) ? xmin : X[count];
        xmax = (xmax > X[count]) ? xmax : X[count];
        ymin = (ymin < Y[count]) ? ymin : Y[count];
        ymax = (ymax > Y[count]) ? ymax : Y[count];
        zmin = (zmin < Z[count]) ? zmin : Z[count];
        zmax = (zmax > Z[count]) ? zmax : Z[count];
        theta += (20*THETA0/NUM_PTS);
    }
    pladv(0);
    plvpor( 0.0, 1.0, 0.0, 0.9 );
    plwind( -1.0, 1.0, -1.0, 1.5 );
    plw3d( 1.0, 1.0, 1.2, xmin, xmax, ymin, ymax, zmin, zmax, 50, 35 );
    plbox3( "bstu", "x axis", 0.0, 0,
            "bstu", "y axis", 0.0, 0,
            "bstu", "z axis", 0.0, 4 );
    plcol(col); plline3(NUM_PTS,X,Y,Z); plcol(15);
    sprintf(txtBuffer, "Conchospiral (#fs#gm=%.2f, a=%1.1f, c=%1.1f#fs)", mu, a, c);
    plptex(0.,1.3, 0, 0, .5, (const char*)txtBuffer);
    plend();
   
    free(X); free(Y); free(Z);
    return 0;
}