1 | /* $Id: log_10.cpp 1370 2009-05-31 05:31:50Z bradbell $ */ |
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2 | /* -------------------------------------------------------------------------- |
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3 | CppAD: C++ Algorithmic Differentiation: Copyright (C) 2003-07 Bradley M. Bell |
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4 | |
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5 | CppAD is distributed under multiple licenses. This distribution is under |
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6 | the terms of the |
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7 | Common Public License Version 1.0. |
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8 | |
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9 | A copy of this license is included in the COPYING file of this distribution. |
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10 | Please visit http://www.coin-or.org/CppAD/ for information on other licenses. |
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11 | -------------------------------------------------------------------------- */ |
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12 | |
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13 | /* |
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14 | Old example now used just for validation testing. |
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15 | */ |
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16 | # include <cppad/cppad.hpp> |
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17 | |
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18 | bool Log10(void) |
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19 | { bool ok = true; |
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20 | |
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21 | using CppAD::log10; |
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22 | using CppAD::log; |
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23 | using namespace CppAD; |
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24 | |
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25 | // independent variable vector, indices, values, and declaration |
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26 | CPPAD_TEST_VECTOR< AD<double> > U(1); |
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27 | size_t s = 0; |
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28 | U[s] = 10.; |
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29 | Independent(U); |
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30 | |
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31 | // dependent variable vector, indices, and values |
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32 | CPPAD_TEST_VECTOR< AD<double> > Z(2); |
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33 | size_t x = 0; |
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34 | size_t y = 1; |
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35 | Z[x] = log10(U[s]); |
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36 | Z[y] = log10(Z[x]); |
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37 | |
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38 | // define f : U -> Z and vectors for derivative calculations |
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39 | ADFun<double> f(U, Z); |
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40 | CPPAD_TEST_VECTOR<double> v( f.Domain() ); |
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41 | CPPAD_TEST_VECTOR<double> w( f.Range() ); |
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42 | |
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43 | // check values |
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44 | ok &= NearEqual(Z[x] , 1., 1e-10 , 1e-10); |
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45 | ok &= NearEqual(Z[y] , 0., 1e-10 , 1e-10); |
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46 | |
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47 | // forward computation of partials w.r.t. s |
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48 | double l10 = log(10.); |
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49 | v[s] = 1.; |
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50 | w = f.Forward(1, v); |
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51 | ok &= NearEqual(w[x], 1./(U[s]*l10) , 1e-10 , 1e-10); // dx/ds |
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52 | ok &= NearEqual(w[y], 1./(U[s]*Z[x]*l10*l10), 1e-10 , 1e-10); // dy/ds |
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53 | |
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54 | // reverse computation of partials of y |
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55 | w[x] = 0.; |
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56 | w[y] = 1.; |
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57 | v = f.Reverse(1,w); |
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58 | ok &= NearEqual(v[s], 1./(U[s]*Z[x]*l10*l10), 1e-10 , 1e-10); // dy/ds |
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59 | |
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60 | return ok; |
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61 | } |
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