/** Calculate the derivatives of each of the supplied points
*
* @param out :: The array to store the calculated derivatives
* @param xValues :: The array of x values we wish to calculate derivatives at
* @param nData :: The size of the arrays
* @param order :: The order of derivatives to calculate too
*/
void CubicSpline::calculateDerivative(double* out, const double* xValues,
const size_t nData, const size_t order) const
{
double xDeriv = 0;
int errorCode = 0;
bool outOfRange(false);
//throw error if the order is not the 1st or 2nd derivative
if(order < 1) throw std::invalid_argument(
"CubicSpline: order of derivative must be 1 or greater");
for(size_t i = 0; i < nData; ++i)
{
if(checkXInRange(xValues[i]))
{
//choose the order of the derivative
if(order == 1)
{
xDeriv = gsl_spline_eval_deriv(m_spline.get(),xValues[i],m_acc.get());
errorCode = gsl_spline_eval_deriv_e (m_spline.get(),xValues[i],m_acc.get(),&xDeriv);
}
else if (order == 2)
{
xDeriv = gsl_spline_eval_deriv2(m_spline.get(),xValues[i],m_acc.get());
errorCode = gsl_spline_eval_deriv2_e (m_spline.get(),xValues[i],m_acc.get(),&xDeriv);
}
}
else
{
//if out of range, just set it to zero
outOfRange = true;
xDeriv = 0;
}
//check GSL functions didn't return an error
checkGSLError(errorCode, GSL_EDOM);
//record the value
out[i] = xDeriv;
}
//warn user that some values weren't calculated
if(outOfRange)
{
g_log.warning() << "Some x values where out of range and will not be calculated." << std::endl;
}
}
static VALUE rb_gsl_spline_eval_deriv_e(VALUE obj, VALUE xx)
{
rb_gsl_spline *rgs = NULL;
double val;
int status;
Data_Get_Struct(obj, rb_gsl_spline, rgs);
Need_Float(xx);
status = gsl_spline_eval_deriv_e(rgs->s, NUM2DBL(xx), rgs->a, &val);
switch (status) {
case GSL_EDOM:
rb_gsl_error_handler("gsl_spline_eval_deriv_e error", __FILE__, __LINE__, status);
break;
default:
return rb_float_new(val);
break;
}
return Qnil;
}
/**
* Function which calculates the value of the waveform, plus its
* first and second derivatives, for the points which will be required
* in the hybrid comb attachment of the ringdown.
*/
static INT4 XLALGenerateHybridWaveDerivatives (
REAL8Vector *rwave, /**<< OUTPUT, values of the waveform at comb points */
REAL8Vector *dwave, /**<< OUTPUT, 1st deriv of the waveform at comb points */
REAL8Vector *ddwave, /**<< OUTPUT, 2nd deriv of the waveform at comb points */
REAL8Vector *timeVec, /**<< Vector containing the time */
REAL8Vector *wave, /**<< Last part of inspiral waveform */
REAL8Vector *matchrange, /**<< Times which determine the size of the comb */
REAL8 dt, /**<< Sample time step */
REAL8 mass1, /**<< First component mass (in Solar masses) */
REAL8 mass2 /**<< Second component mass (in Solar masses) */
)
{
/* XLAL error handling */
INT4 errcode = XLAL_SUCCESS;
/* For checking GSL return codes */
INT4 gslStatus;
UINT4 j;
UINT4 vecLength;
REAL8 m;
double *y;
double ry, dy, dy2;
double rt;
double *tlist;
gsl_interp_accel *acc;
gsl_spline *spline;
/* Total mass in geometric units */
m = (mass1 + mass2) * LAL_MTSUN_SI;
tlist = (double *) LALMalloc(6 * sizeof(double));
rt = (matchrange->data[1] - matchrange->data[0]) / 5.;
tlist[0] = matchrange->data[0];
tlist[1] = tlist[0] + rt;
tlist[2] = tlist[1] + rt;
tlist[3] = tlist[2] + rt;
tlist[4] = tlist[3] + rt;
tlist[5] = matchrange->data[1];
/* Set the length of the interpolation vectors */
vecLength = ( m * matchrange->data[2] / dt ) + 1;
/* Getting interpolation and derivatives of the waveform using gsl spline routine */
/* Initiate arrays and supporting variables for gsl */
y = (double *) LALMalloc(vecLength * sizeof(double));
if ( !y )
{
XLAL_ERROR( XLAL_ENOMEM );
}
for (j = 0; j < vecLength; ++j)
{
y[j] = wave->data[j];
}
XLAL_CALLGSL( acc = (gsl_interp_accel*) gsl_interp_accel_alloc() );
XLAL_CALLGSL( spline = (gsl_spline*) gsl_spline_alloc(gsl_interp_cspline, vecLength) );
if ( !acc || !spline )
{
if ( acc ) gsl_interp_accel_free(acc);
if ( spline ) gsl_spline_free(spline);
LALFree( y );
XLAL_ERROR( XLAL_ENOMEM );
}
/* Gall gsl spline interpolation */
gslStatus = gsl_spline_init(spline, timeVec->data, y, vecLength);
if ( gslStatus != GSL_SUCCESS )
{
gsl_spline_free(spline);
gsl_interp_accel_free(acc);
LALFree( y );
XLAL_ERROR( XLAL_EFUNC );
}
/* Getting first and second order time derivatives from gsl interpolations */
for (j = 0; j < 6; ++j)
{
gslStatus = gsl_spline_eval_e( spline, tlist[j], acc, &ry );
if ( gslStatus == GSL_SUCCESS )
{
gslStatus = gsl_spline_eval_deriv_e(spline, tlist[j], acc, &dy );
gslStatus = gsl_spline_eval_deriv2_e(spline, tlist[j], acc, &dy2 );
}
if (gslStatus != GSL_SUCCESS )
{
gsl_spline_free(spline);
gsl_interp_accel_free(acc);
LALFree( y );
XLAL_ERROR( XLAL_EFUNC );
}
rwave->data[j] = (REAL8)(ry);
dwave->data[j] = (REAL8)(dy/m);
ddwave->data[j] = (REAL8)(dy2/m/m);
}
/* Free gsl variables */
gsl_spline_free(spline);
gsl_interp_accel_free(acc);
LALFree( tlist );
LALFree(y);
return errcode;
}
