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Material data interpolator + Mie T-matrix convenience functions. 

Former-commit-id: 59c9a53bff38a46e357f091c084655192faddb51
This commit is contained in:
Marek Nečada 2019-03-20 23:19:29 +02:00
parent eafd1609a5
commit 115d1d07fe
2 changed files with 183 additions and 2 deletions
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129
qpms/tmatrices.c
View File

@ -20,6 +20,7 @@
#define HBAR (1.05457162825e-34)
#define ELECTRONVOLT (1.602176487e-19)
#define SPEED_OF_LIGHT (2.99792458e8)
#define SCUFF_OMEGAUNIT (3e14)
#define SQ(x) ((x)*(x))
@ -250,7 +251,7 @@ bool qpms_tmatrix_isclose(const qpms_tmatrix_t *A, const qpms_tmatrix_t *B,
}
return true;
}
qpms_tmatrix_interpolator_t *qpms_tmatrix_interpolator_create(const size_t incount,
const double *freqs, const qpms_tmatrix_t *ta, const gsl_interp_type *iptype//, const bool copy_bspec
) {
@ -539,3 +540,129 @@ qpms_errno_t qpms_tmatrix_spherical_fill(qpms_tmatrix_t *t, ///< T-matrix whose
return QPMS_SUCCESS;
}
qpms_permittivity_interpolator_t *qpms_permittivity_interpolator_create(
const size_t incount, const double *wavelen_m, const double *n, const double *k,
const gsl_interp_type *iptype)
{
if (incount <= 0) return NULL;
qpms_permittivity_interpolator_t *ip;
QPMS_CRASHING_MALLOC(ip, sizeof(qpms_permittivity_interpolator_t));
ip->spline_n = gsl_spline_alloc(iptype, incount);
ip->spline_k = gsl_spline_alloc(iptype, incount);
QPMS_ENSURE_SUCCESS(gsl_spline_init(ip->spline_n, wavelen_m, n, incount));
QPMS_ENSURE_SUCCESS(gsl_spline_init(ip->spline_k, wavelen_m, k, incount));
return ip;
}
void qpms_permittivity_interpolator_free(qpms_permittivity_interpolator_t *interp)
{
if(interp) {
gsl_spline_free(interp->spline_n);
gsl_spline_free(interp->spline_k);
}
free(interp);
}
qpms_errno_t qpms_read_refractiveindex_yml(
FILE *f, ///< file handle
size_t *const count, ///< Number of successfully loaded triples.
double* *const lambdas_m, ///< Vacuum wavelengths in metres.
double* *const n, ///< Read refraction indices.
double* *const k ///< Read attenuation coeffs.
)
{
QPMS_ENSURE(f && lambdas_m && n && k,"f, lambdas_m, n, k are mandatory arguments and must not be NULL.");
int count_alloc = 128; // First chunk to allocate
*count = 0;
QPMS_CRASHING_MALLOC(*lambdas_m, count_alloc * sizeof(double));
QPMS_CRASHING_MALLOC(*n, count_alloc * sizeof(double));
QPMS_CRASHING_MALLOC(*k, count_alloc * sizeof(double));
size_t linebufsz = 256;
char *linebuf;
QPMS_CRASHING_MALLOC(linebuf, linebufsz);
ssize_t readchars;
bool data_started = false;
while((readchars = getline(&linebuf, &linebufsz, f)) != -1) {
if (linebuf[0] == '#') continue;
// We need to find the beginning of the tabulated data; everything before that is ignored.
if (!data_started) {
char *test = strstr(linebuf, "data: |");
if(test) data_started = true;
continue;
}
if (3 == sscanf(linebuf, "%lf %lf %lf", *lambdas_m + *count, *n + *count , *k + *count)) {
(*lambdas_m)[*count] *= 1e-6; // The original data is in micrometres.
++*count;
if (*count > count_alloc) {
count_alloc *= 2;
QPMS_CRASHING_REALLOC(*lambdas_m, count_alloc * sizeof(double));
QPMS_CRASHING_REALLOC(*n, count_alloc * sizeof(double));
QPMS_CRASHING_REALLOC(*k, count_alloc * sizeof(double));
}
} else break;
}
QPMS_ENSURE(*count > 0, "Could not read any refractive index data; the format must be wrong!");
free(linebuf);
return QPMS_SUCCESS;
}
qpms_errno_t qpms_load_refractiveindex_yml(
const char *path,
size_t *const count, ///< Number of successfully loaded triples.
double* *const lambdas_m, ///< Vacuum wavelengths in metres.
double* *const n, ///< Read refraction indices.
double* *const k ///< Read attenuation coeffs.
)
{
FILE *f = fopen(path, "r");
QPMS_ENSURE(f, "Could not open refractive index file %s", path);
qpms_errno_t retval =
qpms_read_refractiveindex_yml(f, count, lambdas_m, n, k);
QPMS_ENSURE_SUCCESS(fclose(f));
return retval;
}
qpms_permittivity_interpolator_t *qpms_permittivity_interpolator_from_yml(
const char *path, ///< Path to the yml file.
const gsl_interp_type *iptype ///< GSL interpolator type
)
{
size_t count;
double *lambdas_m, *n, *k;
QPMS_ENSURE_SUCCESS(qpms_load_refractiveindex_yml(path, &count, &lambdas_m, &n, &k));
qpms_permittivity_interpolator_t *ip = qpms_permittivity_interpolator_create(
count, lambdas_m, n, k, iptype);
free(lambdas_m);
free(n);
free(k);
return ip;
}
complex double qpms_permittivity_interpolator_eps_at_omega(
const qpms_permittivity_interpolator_t *ip, double omega_SI)
{
double lambda, n, k;
lambda = 2*M_PI*SPEED_OF_LIGHT/omega_SI;
n = gsl_spline_eval(ip->spline_n, lambda, NULL);
k = gsl_spline_eval(ip->spline_k, lambda, NULL);
complex double epsilon = n*n - k*k + 2*n*k*I;
return epsilon;
}
/// Convenience function to calculate T-matrix of a non-magnetic spherical \
particle using the permittivity values, replacing existing T-matrix data.
qpms_errno_t qpms_tmatrix_spherical_mu0_fill(
qpms_tmatrix_t *t, ///< T-matrix whose contents are to be replaced. Not NULL.
double a, ///< Radius of the sphere.
double omega, ///< Angular frequency.
complex double epsilon_fg, ///< Permittivity of the sphere.
complex double epsilon_bg ///< Permittivity of the background medium.
)
{
complex double k_i = csqrt(epsilon_fg) * omega / SPEED_OF_LIGHT;
complex double k_e = csqrt(epsilon_bg) * omega / SPEED_OF_LIGHT;
return qpms_tmatrix_spherical_fill(t, a, k_i, k_e, 1, 1);
}

56
qpms/tmatrices.h
View File

@ -5,6 +5,7 @@
#define TMATRICES_H
#include "qpms_types.h"
#include <gsl/gsl_spline.h>
#include <stdio.h>
struct qpms_finite_group_t;
typedef struct qpms_finite_group_t qpms_finite_group_t;
@ -137,6 +138,7 @@ qpms_errno_t qpms_load_scuff_tmatrix(
qpms_tmatrix_t **tmatrices_array,
complex double **tmdata ///< The T-matrices raw contents
);
/// Loads a scuff-tmatrix generated file.
/** A simple wrapper over qpms_read_scuff_tmatrix() that needs a
* path instead of open FILE.
@ -248,6 +250,33 @@ qpms_tmatrix_interpolator_t *qpms_tmatrix_interpolator_create(size_t n, ///< Num
//, bool copy_bspec ///< if true, copies its own copy of basis spec from the first T-matrix.
/*, ...? */);
/// Interpolator of tabulated optical properties.
typedef struct qpms_permittivity_interpolator_t {
gsl_spline *spline_n;
gsl_spline *spline_k;
} qpms_permittivity_interpolator_t;
/// Creates a permittivity interpolator from tabulated wavelengths, refraction indices and extinction coeffs.
qpms_permittivity_interpolator_t *qpms_permittivity_interpolator_create(const size_t incount,
const double *wavelength_m, ///< Tabulated vacuum wavelength in metres, in strictly increasing order.
const double *n, ///< Tabulated refraction indices at omega.
const double *k, ///< Tabulated extinction coefficients.
const gsl_interp_type *iptype ///< GSL interpolator type
);
/// Creates a permittivity interpolator from an yml file downloaded from refractiveindex.info website.
qpms_permittivity_interpolator_t *qpms_permittivity_interpolator_from_yml(
const char *path, ///< Path to the yml file.
const gsl_interp_type *iptype ///< GSL interpolator type
);
/// Evaluates interpolated material permittivity at a given angular frequency.
complex double qpms_permittivity_interpolator_eps_at_omega(const qpms_permittivity_interpolator_t *interp, double omega_SI);
/// Destroy a permittivity interpolator.
void qpms_permittivity_interpolator_free(qpms_permittivity_interpolator_t *interp);
/// Calculates the reflection Mie-Lorentz coefficients for a spherical particle.
/**
* This function is based on the previous python implementation mie_coefficients() from qpms_p.py,
@ -298,7 +327,7 @@ static inline qpms_tmatrix_t *qpms_tmatrix_spherical(
/// Relative permittivity from the Drude model.
static inline complex double qpms_drude_epsilon(
complex double eps_inf, ///< Permittivity at
complex double eps_inf, ///< Relative permittivity "at infinity".
complex double omega_p, ///< Plasma frequency \f$ \omega_p \f$ of the material.
complex double gamma_p, ///< Decay constant \f$ \gamma_p \f$ of the material.
complex double omega ///< Frequency \f$ \omega \f$ at which the permittivity is evaluated.
@ -306,6 +335,31 @@ static inline complex double qpms_drude_epsilon(
return eps_inf - omega_p*omega_p/(omega*(omega+I*gamma_p));
}
/// Convenience function to calculate T-matrix of a non-magnetic spherical \
particle using the permittivity values, replacing existing T-matrix data.
qpms_errno_t qpms_tmatrix_spherical_mu0_fill(
qpms_tmatrix_t *t, ///< T-matrix whose contents are to be replaced. Not NULL.
double a, ///< Radius of the sphere.
double omega, ///< Angular frequency.
complex double epsilon_fg, ///< Relative permittivity of the sphere.
complex double epsilon_bg ///< Relative permittivity of the background medium.
);
/// Convenience function to calculate T-matrix of a non-magnetic spherical particle using the permittivity values.
static inline qpms_tmatrix_t *qpms_tmatrix_spherical_mu0(
const qpms_vswf_set_spec_t *bspec,
double a, ///< Radius of the sphere.
double omega, ///< Angular frequency.
complex double epsilon_fg, ///< Relative permittivity of the sphere.
complex double epsilon_bg ///< Relative permittivity of the background medium.
) {
qpms_tmatrix_t *t = qpms_tmatrix_init(bspec);
qpms_tmatrix_spherical_mu0_fill(t, a, omega, epsilon_fg, epsilon_bg);
};
#if 0
// Abstract types that describe T-matrix/particle/scatsystem symmetries
// To be implemented later. See also the thoughts in the beginning of groups.h.