source: sasview/sansmodels/prototypes/src/modelCalculations.c @ 2f5d888

#include "modelCalculations.h"
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <memory.h>
#include <time.h>

/**
 * Initialization function for simulation structure
 */
void modelcalculations_init(CalcParameters *pars) {
        pars->isRhoAvailable         = 0;
        pars->isPointMemAllocated    = 0;
        pars->isRhoAvailable_2D      = 0;
        pars->isPointMemAllocated_2D = 0;
       
        pars->volume_points = 0;
        pars->r_points = 0;
       
                pars->timePr_1D = 0;
        pars->timePr_2D = 0;
        pars->timeIq_1D = 0;
        pars->timeIq_2D = 0;
    
        pars->errorOccured = 0;
        
}

/**
 * Reset function for simulation structure
 */
void modelcalculations_reset(CalcParameters *pars) {
       modelcalculations_dealloc(pars);
       modelcalculations_init(pars);
}

/**
 * Deallocate memory of simullation structure
 */
void modelcalculations_dealloc(CalcParameters *pars) {
        free(pars->rho);
        free(pars->points);
        free(pars->rho_2D);
        free(pars->points_2D);
}

/**
 * Calculate pair correlation for 1D simulation
 */
int modelcalculations_calculatePairCorrelation_1D(SpacePoint * points, int volume_points, double * rho, int r_points, double bin_width) {
        int i,j;
        double dx,dy,dz,dist;
        int i_bin;
        //double bin_width;
        double delta_t;
        double average;
        double closest;
        time_t start_time;
        clock_t start;
        clock_t finish;
        //struct tm *timeStruct;
        
        
        // Allocate memory
        /*
        rho = (double*) malloc(r_points*sizeof(double));
        if(rho==NULL){
                printf("Problem allocating memory for 1D correlation points\n");
                return -1;
        }
        */
        
        // Clear vector
        memset(rho,0,r_points*sizeof(double));

        // R bin width
    //bin_width = 2.0*size/r_points;
    
                time(&start_time);
                start = clock();
                
                
        average = 0;
        for(i=0;i<volume_points-1;i++) {
                closest = -1;
                for(j=i+1;j<volume_points;j++) {
            dx = (points[i].x-points[j].x);
            dy = (points[i].y-points[j].y);
            dz = (points[i].z-points[j].z);
                        dist = sqrt(dx*dx + dy*dy + dz*dz);
                        
                        if(closest<0 || dist<closest) {
                                closest = dist;
                        }
                        
                        //i_bin = (int)dist/bin_width;
                        i_bin = (int)floor(dist/bin_width);
            
            //rho[i_bin] = rho[i_bin] + 1.0/9000000.0;
            if(i_bin >= r_points) {
                printf("problem! %i > %i\n", i_bin, r_points);
            } else {
                rho[i_bin] = rho[i_bin] + 1.0;
            }
                }
                average += closest;
        }
        average = average/(double)volume_points;
        printf("average distance %f\n",average);
        
                finish = clock();
        //time(&end_time);
        //delta_t = difftime(end_time,start_time);
        delta_t = ((double)(finish-start))/CLOCKS_PER_SEC;
        printf("------------->PR calc time = %f\n", delta_t);
    return 1;
}

/**
 * Calculate I(q) for 1D simulation 
 */
double modelcalculations_calculateIq_1D(double * rho, int r_points, double r_step, double q) {
        int i;
        double value;
        //double r_step;
        //double vol;
        double sum;
        double qr;
        clock_t start;
        clock_t finish;
        double delta_t;
        
        start = clock();
        
    //vol = 4.0*acos(-1.0)/3.0*radius*radius*radius;
        //r_step = 2.0*radius/((double)(r_points));
        
        value = 0.0;
        sum = 0.0;
        for(i=1; i<r_points; i++) {
                qr = q*r_step*(double)i;
                value = value + rho[i] * sin(qr) / qr;
                sum = sum + rho[i];
        }
        
        
        value = value/sum;
        
        finish = clock();
    delta_t = ((double)(finish-start))/CLOCKS_PER_SEC;
    //printf("------------->IQ calc time = %f\n", delta_t);
        
        
        return value;
}

/**
 * Calculate pair correlation function for 2D simulation using
 * a 3D array to store P(r)
 */
int modelcalculations_calculatePairCorrelation_2D_3Darray(SpacePoint * points, int volume_points, float * rho, int r_points, double bin_width) {
        int i,j;
        int ix_bin, iy_bin, iz_bin;
        
        clock_t start;
        clock_t finish;
        
        // Clear vector
        memset(rho,0,r_points*r_points*r_points*sizeof(float));

    start = clock();
        for(i=0;i<volume_points-1;i++) {
                for(j=i+1;j<volume_points;j++) {
                        
            // Add entry to the matrix
            ix_bin = (int)floor(fabs(points[i].x-points[j].x)/bin_width);
            iy_bin = (int)floor(fabs(points[i].y-points[j].y)/bin_width);
            iz_bin = (int)floor(fabs(points[i].z-points[j].z)/bin_width);
            
            if(ix_bin < r_points && iy_bin < r_points && iz_bin < r_points) {
                rho[(ix_bin*r_points+iy_bin)*r_points+iz_bin] += 1.0;
            } else {
                printf("Bad point! %i %i %i\n", ix_bin, iy_bin, iz_bin);
            }
                        
                }
        }
        
        finish = clock();
    printf("-------------> Pair Correlation time = %f\n", ((double)(finish-start))/CLOCKS_PER_SEC);
    return 0;
}

/**
 * Calculate pair correlation function for 2D simulation by storing P(r) in a 2D array.
 * Allows for rotation of object in space by specifying theta, phi, omage of the beam
 */
int modelcalculations_calculatePairCorrelation_2D_vector(SpacePoint * points, int volume_points, float * rho, 
                        int r_points, double bin_width, double theta_beam, double phi_beam, double omega_beam) {
        int i,j;
        int ix_bin, iy_bin;
        SpacePoint p1, p2;
        
        clock_t start;
        clock_t finish;
        
        // Clear vector
        memset(rho,0,r_points*r_points*sizeof(float));
        //printf("P(r) with theta=%g phi=%g\n", theta_beam, phi_beam);
    start = clock();
        for(i=0;i<volume_points-1;i++) {
                // Rotate point
                p1 = modelcalculations_rotate(points[i], theta_beam, phi_beam, omega_beam);
                //printf("p = %g %g %g -> %g %g %g\n", points[i].x,points[i].y,points[i].z, p1.x,p1.y,p1.z);
                for(j=i+1;j<volume_points;j++) {
                        // Rotate point
                        p2 = modelcalculations_rotate(points[j], theta_beam, phi_beam, omega_beam);
                        
                        
                        // Calculate distance in plane perpendicular to beam (z)
            ix_bin = (int)floor(fabs(p1.x-p2.x)/bin_width);
            iy_bin = (int)floor(fabs(p1.y-p2.y)/bin_width);
            //iz_bin = (int)floor((points[i].z-points[j].z)/bin_width+r_points/2);
            
            rho[ix_bin*r_points+iy_bin] += 1.0;
                        
                }
        }
        
        finish = clock();
    printf("-------------> 2D (v) Pair Correlation time = %f\n", ((double)(finish-start))/CLOCKS_PER_SEC);
    return 1;
}

/**
 * Calculate pair correlation function for 2D simulation by storing P(r) in a 2D array
 */
int modelcalculations_calculatePairCorrelation_2D(SpacePoint * points, int volume_points, float * rho, int r_points, double bin_width) {
        int i,j;
        int ix_bin, iy_bin;
        
        clock_t start;
        clock_t finish;
        
        // Clear vector
        memset(rho,0,r_points*r_points*sizeof(float));

        //return 1;
        
    start = clock();
        for(i=0;i<volume_points-1;i++) {
                for(j=i+1;j<volume_points;j++) {
                        
                        // Calculate distance in plane perpendicular to beam (z)
            ix_bin = (int)floor(fabs(points[i].x-points[j].x)/bin_width);
            iy_bin = (int)floor(fabs(points[i].y-points[j].y)/bin_width);
            //iz_bin = (int)floor(fabs(points[i].z-points[j].z)/bin_width);
            
            rho[ix_bin*r_points+iy_bin] += 1.0;
            //rho[ix_bin*r_points+iy_bin] += fabs(points[i].z-points[j].z);
                }
        }
        
        finish = clock();
    printf("-------------> Pair Correlation time = %f\n", ((double)(finish-start))/CLOCKS_PER_SEC);
    
    /*
     * for(i=0;i<r_points;i++) {
        for(j=0;j<r_points;j++) {
                printf("Pr(%i, %i) = %g\n", i, j, rho[i*r_points+j]);
        }       
        
    }
    */
        return 0;
}

/**
 * Calculate I(q) for 2D simulation from 3D array
 */
double modelcalculations_calculateIq_2D_3Darray(float * rho, int r_points, double r_step, double q, double phi) {
        //TODO: make rho an array of ints.
        
        int ix,iy,iz;
        
        // This should be a parameter
        double lambda = 1.6;
        double theta;
        double value;
        double sum;
        // This should also be a parameter, about value of radius
        double r_max = 1;
        //double r_step =1;
        
        double c1;
        double c2;
        double c3;
        int r2;
        double f3;
        double iz_c;
        clock_t start; 
        clock_t finish;
        
        theta = 2*asin(q*lambda/(4*acos(-1.0)));
        
        value = 0.0;
        sum = 0.0;
        //c1 = lambda*(cos(theta)-1)*r_step;
        //c2 = lambda*sin(theta)*cos(phi)*r_step;
        //c3 = lambda*sin(theta)*sin(phi)*r_step;
        
        c1 = 0;
        c2 = q*cos(phi)*r_step;
        c3 = q*sin(phi)*r_step;
        
        start = clock();
        
        // TODO: sum(rho) should be equal to the number of points^2 !
        
        for(ix=0; ix<r_points; ix++) {
                for(iy=0; iy<r_points; iy++) {
                        r2 = ix*r_points*r_points+iy*r_points;
                        f3 = c2*(ix-r_points/2) + c3*(iy-r_points/2);
                        for(iz=0; iz<r_points; iz++) {
                                iz_c = (double)iz-r_points/2; 
                                value = value + rho[r2+iz] * cos( c1*iz_c + f3 );
                                sum = sum + rho[r2+iz];
                        }
                }
        }
        finish = clock();
    //printf("-------------> I(Q) time = %f, (%f %f %f)\n", ((double)(finish-start))/CLOCKS_PER_SEC, q, phi,value/sum);
        
        
        value = value /sum;
        return value;
}

/**
 * Pair correlation function for a sphere
 *      @param r: distance value
 */
double pair_corr_sphere(double r) {
        
        return r*r*(1.0 - 0.75*r + r*r*r/16.0); 
}

/** 
 * Calculate I(q) for 2D simulation from 2D array P(r)
 */
double modelcalculations_calculateIq_2D(float * rho, int r_points, double r_step, double q, double phi) {
        //TODO: make rho an array of ints.
        
        int ix,iy;
        
        // This should be a parameter
        double lambda = 1.0;
        double value;
        double sum;
        // This should also be a parameter, about value of radius
        double r_max = 1;
        //double r_step =1;
        
        double c2;
        double c3;
        int ibin;
        clock_t start; 
        clock_t finish;
        
        //theta = 2*asin(q*lambda/(4*acos(-1.0)));
        value = 0.0;
        sum = 0.0;
        c2 = q*cos(phi)*r_step;
        c3 = q*sin(phi)*r_step;
        //printf("phi = %g, c2=%g, c3=%g, q=%g, r_step=%g\n",phi, c2, c3,q,r_step);
        
        start = clock();
        
        for(ix=-r_points+1; ix<r_points; ix++) {
                for(iy=-r_points+1; iy<r_points; iy++) {
                        
                        //value += rho[ix*r_points+iy] * cos( c2*((double)ix+0.5) + c3*((double)iy+0.5) );
                        //sum += rho[ix*r_points+iy];
                        
                        ibin = (int)(floor(sqrt(1.0*ix*ix)))*r_points+(int)(floor(sqrt(1.0*iy*iy)));
                        
                        if (ibin<r_points*r_points) {
                        
                                //value += rho[ibin] * cos( c2*((double)ix+0.5) + c3*((double)iy+0.5) );
                        
                                value += rho[ibin] * cos( c2*((double)ix) + c3*((double)iy) );
                                
                                sum += rho[ibin];
                        } else {
                                printf("Error computing IQ %i >= %i (%i %i)\n", ibin, r_points*r_points,ix, iy);
                        };
                        
                        
                        //dx = r_step*((double)ix+0.5);
                        //dy = r_step*((double)iy+0.5);
                        
                        // Only works for sphere of radius = 20
                        //f3 = pair_corr_sphere(sqrt(dx*dx+dy*dy)/20.0);
                        
                        //value += f3 * cos( c2*(dx) + c3*(dy) );
                        //sum += f3;            
                }
        }
        finish = clock();
        
        value = value /sum;
        return value;
}


/**
 *  Rotation of a space point
 */
SpacePoint modelcalculations_rotate(SpacePoint p, double theta, double phi, double omega) {
        SpacePoint new_point;
        double x_1, x_2;
        double y_1, y_2;
        double z_1, z_2;
        // P(r) assumes beam along z-axis. Rotate point accordingly
        
        
        // Omega, around z-axis (doesn't change anything for cylindrical symmetry
        x_1 = p.x*cos(omega) - p.y*sin(omega);
        y_1 = p.x*sin(omega) + p.y*cos(omega);
        z_1 = p.z;      
        
        // Theta, around y-axis
        x_2 = x_1*cos(theta) + z_1*sin(theta);
        y_2 = y_1;
        z_2 = -x_1*sin(theta) + z_1*cos(theta);
        
        // Phi, around z-axis
        new_point.x = x_2*cos(phi) - y_2*sin(phi);
        new_point.y = x_2*sin(phi) + y_2*cos(phi);
        new_point.z = z_2;
        
        return new_point;       
}