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97 lines
2.5 KiB
97 lines
2.5 KiB
#! /usr/bin/env ruby |
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# This is 'curve1.c' demo done with RubyInline gem (instead of using swig) |
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# Contributed by Igor Drozdov <idrozdov@gmail.com> 2012 |
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# $ ruby curve1_rubyinline.rb |
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# |
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# Requirements: |
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# |
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# $ gem install RubyInline |
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# |
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# To make sure header files and shared librares can be found, |
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# export appropriate LD_LIBRARY_PATH and C_INCLUDE_PATH. |
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require 'rubygems' |
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require 'inline' |
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class Curve |
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inline(:C) do |builder| |
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builder.include("\"lmcurve.h\"") |
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builder.include("\"lmmin.h\"") |
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builder.include("<math.h>") |
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builder.include("<stdio.h>") |
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builder.include("<ruby.h>)") |
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builder.add_link_flags("-llmmin") |
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builder.c_raw <<EOC |
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double f( double t, const double *p ) |
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{ |
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return p[0] + p[1]*(t-p[2])*(t-p[2]); |
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} |
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EOC |
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builder.c <<EOC |
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VALUE demo(VALUE t_ary, VALUE y_ary) { |
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/* parameter vector */ |
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int n_par = 3; // number of parameters in model function f |
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double par[3] = { 1, 0, -1 }; // relatively bad starting value |
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/* data pairs: slightly distorted standard parabola */ |
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int m_dat = 11; // number of data pairs |
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int i; |
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/* ruby macros dealing with inputs */ |
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int t_len = RARRAY_LEN(t_ary); |
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int y_len = RARRAY_LEN(y_ary); |
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double t[t_len]; |
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double y[t_len]; |
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VALUE *t_arr = RARRAY_PTR(t_ary); |
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VALUE *y_arr = RARRAY_PTR(y_ary); |
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VALUE result_pars = rb_ary_new(); // ruby array containing fitted params |
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/* auxiliary parameters */ |
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lm_status_struct status; |
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lm_control_struct control = lm_control_double; |
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for (i = 0; i < t_len; i++) { |
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t[i] = NUM2DBL(t_arr[i]); |
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y[i] = NUM2DBL(y_arr[i]); |
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} |
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lmcurve_fit( n_par, par, m_dat, t, y, f, &control, &status ); |
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/* print results */ |
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printf( "\\nResults:\\n" ); |
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printf( "status after %d function evaluations:\\n %s\\n", |
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status.nfev, lm_infmsg[status.outcome] ); |
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printf("obtained parameters:\\n"); |
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for ( i = 0; i < n_par; ++i) |
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rb_ary_push(result_pars,DBL2NUM(par[i])); |
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printf(" par[%i] = %12g\\n", i, par[i]); |
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printf("obtained norm:\\n %12g\\n", status.fnorm ); |
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printf("fitting data as follows:\\n"); |
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for ( i = 0; i < m_dat; ++i) |
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printf( " t[%2d]=%12g y=%12g fit=%12g residue=%12g\\n", |
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i, t[i], y[i], f(t[i],par), y[i] - f(t[i],par) ); |
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printf("\\n"); |
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return result_pars; |
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} |
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EOC |
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end |
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end |
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# |
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t = [ -5.0, -4.0, -3.0, -2.0, -1.0, 0.0, 1.0, 2.0, 3.0, 4.0, 5.0 ] |
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y = [ 25.5, 16.6, 9.9, 4.4, 1.1, 0, 1.1, 4.2, 9.3, 16.4, 25.5 ] |
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c = Curve.new |
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p c.demo(t,y)
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