The behavior of stack (growing up or growing down) depends on the application binary interface (ABI) and how the call stack (aka activation record) is organized. Throughout its lifetime a program is bound to communicate with other programs like OS. ABI determines how a program can communicate with another program. The stack for different architectures … Read more
In this case, double means a variable of type double. double* means a pointer to a double variable. double** means a pointer to a pointer to a double variable. In the case of the function you posted, it is used to create a sort of two-dimensional array of doubles. That is, a pointer to an array of double pointers, … Read more
I think you’re reading those stats incorrectly. They show that Python is up to about 400 times slower than C++ and with the exception of a single case, Python is more of a memory hog. When it comes to source size though, Python wins flat out. My experiences with Python show the same definite trend … Read more
Even if you’re not allocating memory directly, it happens under the hood in vector code and you most likely corrupted some portion of memory by writing where you are not supposed to. The most likely reasons I can think of are: Writing to an element that is out of bounds Using a pointer/reference to an element that … Read more
How do I determine the size of an object in Python? The answer, “Just use sys.getsizeof“, is not a complete answer. That answer does work for builtin objects directly, but it does not account for what those objects may contain, specifically, what types, such as custom objects, tuples, lists, dicts, and sets contain. They can contain instances each … Read more
I’ve found a workaround. At first it seemed it would take up more time, but it actually makes everything work smoother and faster due to less swapping and more memory available. This is not a scientific approach and it needs some testing before it works. In the code, make Excel save the workbook every now … Read more
I also faced this issue with my Ubuntu 14.04 desktop. Even these basic command showed Can’t allocate memory error. On investigating, found that system is using all the memory for Caching and is not freeing up memory. This is called Cache Ballooning and solved this by clearing the cache.
Your code has undefined behaviour because you are trying to assign l from an uninitialised array str. I’m guessing you got your functions confused and meant to write the opposite That code assigns l to str. Use the following code to work out how big str needs to be
he guarantee you get is that sizeof(char) == 1. There are no other guarantees, including no guarantee that sizeof(int *) == sizeof(double *). In practice, pointers will be size 2 on a 16-bit system (if you can find one), 4 on a 32-bit system, and 8 on a 64-bit system, but there’s nothing to be gained in … Read more
Rewrite to and this will use much less memory. Whereas p = p*alpha allocates a whole new matrix for the result of p*alpha and then discards the old p; p*= alpha does the same thing in place. In general, with big matrices, try to use op= assignment.