source: sasview/src/sas/sascalc/calculator/c_extensions/sld2i.cpp @ acefa2b

/**
Computes the (magnetic) scattering form sld (n and m) profile
 */
#include "sld2i.hh"
#include <stdio.h>
#include <math.h>
using namespace std;
extern "C" {
        #include "libfunc.h"
        #include "librefl.h"
}
/**
 * Constructor for GenI
 *
 * binning
 * //@param qx: array of Qx values
 * //@param qy: array of Qy values
 * //@param qz: array of Qz values
 * @param x: array of x values
 * @param y: array of y values
 * @param z: array of z values
 * @param sldn: array of sld n
 * @param mx: array of sld mx
 * @param my: array of sld my
 * @param mz: array of sld mz
 * @param in_spin: ratio of up spin in Iin
 * @param out_spin: ratio of up spin in Iout
 * @param s_theta: angle (from x-axis) of the up spin in degree
 */
GenI :: GenI(int npix, double* x, double* y, double* z, double* sldn,
                        double* mx, double* my, double* mz, double* voli,
                        double in_spin, double out_spin,
                        double s_theta) {
        //this->qx_val = qx;
        //this->qy_val = qy;
        //this->qz_val = qz;
        this->n_pix = npix;
        this->x_val = x;
        this->y_val = y;
        this->z_val = z;
        this->sldn_val = sldn;
        this->mx_val = mx;
        this->my_val = my;
        this->mz_val = mz;
        this->vol_pix = voli;
        this->inspin = in_spin;
        this->outspin = out_spin;
        this->stheta = s_theta;
};

/**
 * Compute 2D anisotropic
 */
void GenI :: genicomXY(int npoints, double *qx, double *qy, double *I_out){
        //npoints is given negative for angular averaging 
        // Assumes that q doesn't have qz component and sld_n is all real
        //double q = 0.0;
        //double Pi = 4.0*atan(1.0);
        polar_sld b_sld;
        double qr = 0.0;
        complex iqr = cassign(0.0, 0.0);
        complex ephase = cassign(0.0, 0.0);
        complex comp_sld = cassign(0.0, 0.0);

        complex sumj_uu;
        complex sumj_ud;
        complex sumj_du;
        complex sumj_dd;
        complex temp_fi;

        double count = 0.0;
        //check if this computation is for averaging

        //Assume that pixel volumes are given in vol_pix in A^3 unit
        //int x_size = 0; //in Ang
        //int y_size = 0; //in Ang
        //int z_size = 0; //in Ang
        
        // Loop over q-values and multiply apply matrix
        
        for(int i=0; i<npoints; i++){
                //I_out[i] = 0.0;
                sumj_uu = cassign(0.0, 0.0);
                sumj_ud = cassign(0.0, 0.0);
                sumj_du = cassign(0.0, 0.0);
                sumj_dd = cassign(0.0, 0.0);            
                //printf ("%d ", i);
                //q = sqrt(qx[i]*qx[i] + qy[i]*qy[i]); // + qz[i]*qz[i]);

                for(int j=0; j<n_pix; j++){
                        if (sldn_val[j]!=0.0||mx_val[j]!=0.0||my_val[j]!=0.0||mz_val[j]!=0.0)
                        {       
                                //anisotropic
                                temp_fi = cassign(0.0, 0.0);
                                b_sld = cal_msld(0, qx[i], qy[i], sldn_val[j],
                                                         mx_val[j], my_val[j], mz_val[j],
                                                         inspin, outspin, stheta);
                                qr = (qx[i]*x_val[j] + qy[i]*y_val[j]);
                                iqr = cassign(0.0, qr);
                                ephase = cplx_exp(iqr);
                                
                                //Let's multiply pixel(atomic) volume here
                                ephase = rcmult(vol_pix[j], ephase);
                                //up_up
                                if (inspin > 0.0 && outspin > 0.0){
                                        comp_sld = cassign(b_sld.uu, 0.0);
                                        temp_fi = cplx_mult(comp_sld, ephase);
                                        sumj_uu = cplx_add(sumj_uu, temp_fi);
                                }
                                //down_down
                                if (inspin < 1.0 && outspin < 1.0){
                                        comp_sld = cassign(b_sld.dd, 0.0);
                                        temp_fi = cplx_mult(comp_sld, ephase);
                                        sumj_dd = cplx_add(sumj_dd, temp_fi);
                                }
                                //up_down
                                if (inspin > 0.0 && outspin < 1.0){
                                        comp_sld = cassign(b_sld.re_ud, b_sld.im_ud);
                                        temp_fi = cplx_mult(comp_sld, ephase);
                                        sumj_ud = cplx_add(sumj_ud, temp_fi);
                                }
                                //down_up
                                if (inspin < 1.0 && outspin > 0.0){
                                        comp_sld = cassign(b_sld.re_du, b_sld.im_du);
                                        temp_fi = cplx_mult(comp_sld, ephase);
                                        sumj_du = cplx_add(sumj_du, temp_fi);
                                }


                                if (i == 0){
                                        count += vol_pix[j];
                                }
                        }
                }
                //printf("aa%d=%g %g %d\n", i, (sumj_uu.re*sumj_uu.re + sumj_uu.im*sumj_uu.im), (sumj_dd.re*sumj_dd.re + sumj_dd.im*sumj_dd.im), count);

                I_out[i] = (sumj_uu.re*sumj_uu.re + sumj_uu.im*sumj_uu.im);
                I_out[i] += (sumj_ud.re*sumj_ud.re + sumj_ud.im*sumj_ud.im);
                I_out[i] += (sumj_du.re*sumj_du.re + sumj_du.im*sumj_du.im);
                I_out[i] += (sumj_dd.re*sumj_dd.re + sumj_dd.im*sumj_dd.im);

                I_out[i] *= (1.0E+8 / count); //in cm (unit) / number; //to be multiplied by vol_pix
        }
        //printf ("count = %d %g %g %g %g\n", count, sldn_val[0],mx_val[0], my_val[0], mz_val[0]);
}
/**
 * Compute 1D isotropic
 * Isotropic: Assumes all slds are real (no magnetic)
 * Also assumes there is no polarization: No dependency on spin
 */
void GenI :: genicom(int npoints, double *q, double *I_out){
        //npoints is given negative for angular averaging 
        // Assumes that q doesn't have qz component and sld_n is all real
        //double Pi = 4.0*atan(1.0);
        int is_sym = 0;
        double qr = 0.0;
        double sumj;
        double sld_j = 0.0;
        double count = 0.0;
        if (n_pix < 0 ){
                is_sym = 1;
                n_pix = n_pix * -1;
        }
        //Assume that pixel volumes are given in vol_pix in A^3 unit
        // Loop over q-values and multiply apply matrix
        for(int i=0; i<npoints; i++){
                sumj =0.0;              
                for(int j=0; j<n_pix; j++){
                        //Isotropic: Assumes all slds are real (no magnetic)
                        //Also assumes there is no polarization: No dependency on spin
                        if (is_sym == 1){
                                // approximation for a spherical symmetric particle
                                qr = sqrt(x_val[j]*x_val[j]+y_val[j]*y_val[j]+z_val[j]*z_val[j])*q[i];
                                if (qr > 0.0){
                                        qr = sin(qr) / qr;
                                        sumj += sldn_val[j] * vol_pix[j] * qr;
                                }
                                else{
                                        sumj += sldn_val[j] * vol_pix[j];
                                }
                        }
                        else{
                                //full calculation
                                //pragma omp parallel for
                                for(int k=0; k<n_pix; k++){
                                        sld_j =  sldn_val[j] * sldn_val[k] * vol_pix[j] * vol_pix[k];
                                        qr = (x_val[j]-x_val[k])*(x_val[j]-x_val[k])+
                                                      (y_val[j]-y_val[k])*(y_val[j]-y_val[k])+ 
                                                      (z_val[j]-z_val[k])*(z_val[j]-z_val[k]);
                                        qr = sqrt(qr) * q[i];
                                        if (qr > 0.0){
                                                sumj += sld_j*sin(qr)/qr;
                                        }
                                        else{
                                                sumj += sld_j;
                                        }
                                }
                        }
                        if (i == 0){
                                count += vol_pix[j];
                        }
                }
                I_out[i] = sumj;
                if (is_sym == 1){
                        I_out[i] *= sumj;
                }
                I_out[i] *= (1.0E+8 / count); //in cm (unit) / number; //to be multiplied by vol_pix
        }
        //printf ("count = %d %g %g %g %g\n", count, sldn_val[0],mx_val[0], my_val[0], mz_val[0]);
}