Dorival Pedroso cpmech

🦀

Rusting

Senior Lecturer @ UQ

cpmech / seg_fault_does_not_happen.cpp

Last active August 26, 2024 08:03

Dangers of using C/C++ lambda functions (NO warnings from the compiler!)

	#include <functional>
	#include <iostream>
	#include <vector>

	using namespace std;

	const size_t NNODE = 3;

	void print_x(size_t num_triangle, function<vector<double> const *(size_t, size_t)> get_x) {
	for (size_t t = 0; t < num_triangle; t++) {

cpmech / evil-floating-point-compuattions.txt

Last active January 30, 2023 02:38

Float point numbers are evil. The answer should be 2; but we get 0

	Evil Floating-Point Computations (using Mathematica 13.1)

	Analytical
	In[1]:= a={32 10^7,1,-1,8 10^7}
	Out[1]= {320000000,1,-1,80000000}
	In[2]:= b={4 10^7,1,-1,-16 10^7}
	Out[2]= {40000000,1,-1,-160000000}
	In[3]:= a b
	Out[3]= {12800000000000000,1,1,-12800000000000000}
	In[4]:= Total[a b]