32 lines
952 B
C++
32 lines
952 B
C++
// NOTE: 多变量函数的导数
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// C++ includes
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#include <iostream>
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// autodiff include
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#include <autodiff/forward/dual.hpp>
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using namespace autodiff;
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// The multi-variable function for which derivatives are needed
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dual f(dual x, dual y, dual z)
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{
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return 1 + x + y + z + x*y + y*z + x*z + x*y*z + exp(x/y + y/z);
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}
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int main()
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{
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dual x = 1.0;
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dual y = 2.0;
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dual z = 3.0;
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dual u = f(x, y, z);
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double dudx = derivative(f, wrt(x), at(x, y, z));
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double dudy = derivative(f, wrt(y), at(x, y, z));
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double dudz = derivative(f, wrt(z), at(x, y, z));
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std::cout << "u = " << u << std::endl; // print the evaluated output u = f(x, y, z)
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std::cout << "du/dx = " << dudx << std::endl; // print the evaluated derivative du/dx
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std::cout << "du/dy = " << dudy << std::endl; // print the evaluated derivative du/dy
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std::cout << "du/dz = " << dudz << std::endl; // print the evaluated derivative du/dz
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} |