Author |
Topic |
|
u@nlo
India
10 Posts |
Posted - 01/03/2014 : 12:50:38 AM
|
Origin Ver.8.5 and Service Release 1 (Select Help-->About Origin): Operating System: windows7
Can anyone please provide help in code for the above function. here user data consists of Z and T(Z) values (100 points and above values) remaing all are constant parameters. I tried with modifying coding of another fun..still i lost my continuity at many stages.
Here is the code i tried with many mistakes.
Can anyone please assist me in this part.
#pragma warning(error : 15618)
#include <origin.h>
// Add your special include files here.
// For example, if you want to fit with functions from the NAG library,
// add the header file for the NAG functions here.
#include <oc_nag8.h>
// Add code here for other Origin C functions that you want to define in this file,
// and access in your fitting function.
struct user // parameters in the integrand
{
double amp, center, width;
};
// Function supplied by user, return the value of the integrand at a given x.
static double NAG_CALL f_callback(double x, Nag_User *comm)
{
struct user *sp = (struct user *)(comm->p);
double amp, center, width; // temp variable to accept the parameters in the Nag_User communication struct
amp = sp->amp;
center = sp->center;
width = sp->width;
return amp * exp( -2*(x - center)*(x - center)/width/width ) / (width*sqrt(PI/2));
}
// You can access C functions defined in other files, if those files are loaded and compiled
// in your workspace, and the functions have been prototyped in a header file that you have
// included above.
// You can access NLSF object methods and properties directly in your function code.
// You should follow C-language syntax in defining your function.
// For instance, if your parameter name is P1, you cannot use p1 in your function code.
// When using fractions, remember that integer division such as 1/2 is equal to 0, and not 0.5
// Use 0.5 or 1/2.0 to get the correct value.
// For more information and examples, please refer to the "User-Defined Fitting Function"
// section of the Origin Help file.
//----------------------------------------------------------
//
void _nlsfzscan(
// Fit Parameter(s):
double i0, double L, double x0, double l0, double a0, double lmd, double yo, double b,
// Independent Variable(s):
double x,
// Dependent Variable(s):
double& y)
{
// Beginning of editable part
L=(1-exp(-a0*l))/a0;
x'=i0*L*(1+(x/x0)^2);
y0=1/(sqrt(pi)*x');
// Through the absolute accuracy epsabs, relative accuracy epsrel and max_num_subint you can
// control the precision of the integration you need
// if epsrel is set negative, the absolute accuracy will be used.
// Similarly, you can control only relative accuracy by set the epsabs negative
double epsabs = 0.0, epsrel = 0.0001;
// The max number of sub-intervals needed to evaluate the function in the integral
// The more diffcult the integrand the larger max_num_subint should be
// For most problems 200 to 500 is adequate and recommmended
Integer max_num_subint = 200;
// Result keeps the approximate integral value returned by the algorithm
// abserr is an estimate of the error which should be an upper bound for the |I - result|
// where I is the integral value
double result, abserr;
// The structure of type Nag_QuadProgress,
// it contains pointers allocated memory internally with max_num_subint elements
Nag_QuadProgress qp;
// The NAG error parameter (structure)
static NagError fail;
// Parameters passed to integrand by Nag_User communication struct
Nag_User comm;
struct user s;
s.amp = A;
s.center = xc;
s.width = w;
comm.p = (Pointer)&s;
// Perform integration
// There are 3 kinds of infinite boundary types you can use in Nag infinite integrator
// Nag_LowerSemiInfinite, Nag_UpperSemiInfinite, Nag_Infinite
d01smc(f_callback, Nag_Infinite, x, epsabs, epsrel, max_num_subint, &result, &abserr, &qp, &comm, &fail);
// you may want to exam the error by printing out error message, just uncomment the following lines
// if (fail.code != NE_NOERROR)
// printf("%s\n", fail.message);
// For the error other than the following three errors which are due to bad input parameters
// or allocation failure NE_INT_ARG_LT NE_BAD_PARAM NE_ALLOC_FAIL
// You will need to free the memory allocation before calling the integration routine again to avoid memory leakage
if (fail.code != NE_INT_ARG_LT && fail.code != NE_BAD_PARAM && fail.code != NE_ALLOC_FAIL)
{
NAG_FREE(qp.sub_int_beg_pts);
NAG_FREE(qp.sub_int_end_pts);
NAG_FREE(qp.sub_int_result);
NAG_FREE(qp.sub_int_error);
}
// Calculate the fitted value
y = (y0/b)*result;
// End of editable part
}
<b><i>U@NLO</i></b> |
|
Sam Fang
293 Posts |
Posted - 01/10/2014 : 12:39:49 AM
|
For z0=pi*w0^2/lmd , over parameterization exists in w0 and lmd, so here we used z0 as the parameter. You can apply a constraint to get w0 and lmd from z0. The fitting function can be defined as: ---------------------------------------
#include <oc_nag8.h>
struct user // parameters in the integrand
{
double q;
};
// Function supplied by user, return the value of the integrand at a given x.
static double NAG_CALL f_callback(double x, Nag_User *comm)
{
struct user *sp = (struct user *)(comm->p);
double q; // temp variable to accept the parameters in the Nag_User communication struct
q = sp->q;;
return ln(1+q*exp(-x^2));
}
void _nlsfzscan(
// Fit Parameter(s):
double i0, double a0, double l, double b, double z0,
// Independent Variable(s):
double x,
// Dependent Variable(s):
double& y)
{
// Beginning of editable part
double L,q;
L=(1-exp(-a0*l))/a0;
q=b*i0*L*(1+(x/z0)^2);
// Through the absolute accuracy epsabs, relative accuracy epsrel and max_num_subint you can
// control the precision of the integration you need
// if epsrel is set negative, the absolute accuracy will be used.
// Similarly, you can control only relative accuracy by set the epsabs negative
double epsabs = 0.0, epsrel = 0.0001;
// The max number of sub-intervals needed to evaluate the function in the integral
// The more diffcult the integrand the larger max_num_subint should be
// For most problems 200 to 500 is adequate and recommmended
Integer max_num_subint = 200;
// Result keeps the approximate integral value returned by the algorithm
// abserr is an estimate of the error which should be an upper bound for the |I - result|
// where I is the integral value
double result, abserr;
// The structure of type Nag_QuadProgress,
// it contains pointers allocated memory internally with max_num_subint elements
Nag_QuadProgress qp;
// The NAG error parameter (structure)
static NagError fail;
// Parameters passed to integrand by Nag_User communication struct
Nag_User comm;
struct user s;
s.q = q;
comm.p = (Pointer)&s;
// Perform integration
// There are 3 kinds of infinite boundary types you can use in Nag infinite integrator
double bound;
// Nag_LowerSemiInfinite, Nag_UpperSemiInfinite, Nag_Infinite
d01smc(f_callback, Nag_Infinite, bound, epsabs, epsrel, max_num_subint, &result, &abserr, &qp, &comm, &fail);
// you may want to exam the error by printing out error message, just uncomment the following lines
// if (fail.code != NE_NOERROR)
// printf("%s\n", fail.message);
// For the error other than the following three errors which are due to bad input parameters
// or allocation failure NE_INT_ARG_LT NE_BAD_PARAM NE_ALLOC_FAIL
// You will need to free the memory allocation before calling the integration routine again to avoid memory leakage
if (fail.code != NE_INT_ARG_LT && fail.code != NE_BAD_PARAM && fail.code != NE_ALLOC_FAIL)
{
NAG_FREE(qp.sub_int_beg_pts);
NAG_FREE(qp.sub_int_end_pts);
NAG_FREE(qp.sub_int_result);
NAG_FREE(qp.sub_int_error);
}
// Calculate the fitted value
y = 1/sqrt(pi)/q*result;
// End of editable part
}
---------------------------------------
Sam OriginLab Technical Services |
|
|
|
Topic |
|
|
|