optimization

来源： https://stackoverflow.com/questions/63424356/how-to-optimise-rcpp-function-calling-another-r-function

来源： https://stackoverflow.com/questions/63424356/how-to-optimise-rcpp-function-calling-another-r-function

来源： https://stackoverflow.com/questions/60043995/tolerance-for-termination-is-ignored-in-scipy-optimize-minimize

来源： https://stackoverflow.com/questions/60043995/tolerance-for-termination-is-ignored-in-scipy-optimize-minimize

来源： https://stackoverflow.com/questions/63290233/maximum-sharpe-ratio-portfolio-fails-with-error-in-portfolioanalytics

问题 Motivated by this question, I compared three different functions for checking if 8 bytes pointed to by the argument are zeros (note that in the original question, characters are compared with '0' , not 0 ): bool f1(const char *ptr) { for (int i = 0; i < 8; i++) if (ptr[i]) return false; return true; } bool f2(const char *ptr) { bool res = true; for (int i = 0; i < 8; i++) res &= (ptr[i] == 0); return res; } bool f3(const char *ptr) { static const char tmp[8]{}; return !std::memcmp(ptr, tmp, 8

问题 Motivated by this question, I compared three different functions for checking if 8 bytes pointed to by the argument are zeros (note that in the original question, characters are compared with '0' , not 0 ): bool f1(const char *ptr) { for (int i = 0; i < 8; i++) if (ptr[i]) return false; return true; } bool f2(const char *ptr) { bool res = true; for (int i = 0; i < 8; i++) res &= (ptr[i] == 0); return res; } bool f3(const char *ptr) { static const char tmp[8]{}; return !std::memcmp(ptr, tmp, 8

问题 Motivated by this question, I compared three different functions for checking if 8 bytes pointed to by the argument are zeros (note that in the original question, characters are compared with '0' , not 0 ): bool f1(const char *ptr) { for (int i = 0; i < 8; i++) if (ptr[i]) return false; return true; } bool f2(const char *ptr) { bool res = true; for (int i = 0; i < 8; i++) res &= (ptr[i] == 0); return res; } bool f3(const char *ptr) { static const char tmp[8]{}; return !std::memcmp(ptr, tmp, 8

问题 Motivated by this question, I compared three different functions for checking if 8 bytes pointed to by the argument are zeros (note that in the original question, characters are compared with '0' , not 0 ): bool f1(const char *ptr) { for (int i = 0; i < 8; i++) if (ptr[i]) return false; return true; } bool f2(const char *ptr) { bool res = true; for (int i = 0; i < 8; i++) res &= (ptr[i] == 0); return res; } bool f3(const char *ptr) { static const char tmp[8]{}; return !std::memcmp(ptr, tmp, 8

问题 So I have a list with several <li> elements, <ul> <li>a</li> <li>b</li> <li>c</li> <li>d</li> <li>e</li> <li>f</li> <li>g</li> <li>h</li> </ul> The context is I want to re-use li elements across a 1,000 memory intensive list for iOS. The objective is to display first 4 elements, the rest 4 are hidden, the container displays 4 items at a time. On scroll (button tap), I'm going to animate the list and slide in the other 4, and at the end of the animation, move the first 4 li items towards the