Issue For x-ray diffraction one needs to find the solutions to the so called Laue-Equation G_hkl – k_in + |k_in|*(sin(theta) cos(phi) , sin(theta) sin(phi) , cos(theta))=0 where G_hkl is a given 3 dimensional vector, k_in can be chosen as (0,0,1)

Continue reading# Category: performance

## [SOLVED] How to find Bragg reflexes fast with numpy?

Issue For x-ray diffraction one needs to find the solutions to the so called Laue-Equation G_hkl – k_in + |k_in|*(sin(theta) cos(phi) , sin(theta) sin(phi) , cos(theta))=0 where G_hkl is a given 3 dimensional vector, k_in can be chosen as (0,0,1)

Continue reading## [SOLVED] find Duplicate Element from a List of Integer without using Stream's distinct method

Issue Recently this question is asked in Interview : How to find the Duplicate Elements from a List of Integer without using java Stream’s distinct method ? This should be done by Java’s Stream API but should not use distinct()

Continue reading## [SOLVED] Numba @guvectorize([(float64[:], int64)], '(n),()->(n)') IndexError: list index out of range

Issue I try to apply Numba to my code to improve the speed. But I get an error " IndexError: list index out of range" and warnings. How can I make it works? I run the code as below: import

Continue reading## [SOLVED] Hibernate out of memory exception while processing large collection of elements

Issue I am trying to process collection of heavy weight elements (images). Size of collection varies between 8000 – 50000 entries. But for some reason after processing 1800-1900 entries my program falls with java.lang.OutOfMemoryError: Java heap space. In my understanding

Continue reading## [SOLVED] Efficiently Calculating a Euclidean Distance Matrix Using Numpy

Issue I have a set of points in 2-dimensional space and need to calculate the distance from each point to each other point. I have a relatively small number of points, maybe at most 100. But since I need to

Continue reading## [SOLVED] Slowness to Remove 3,7 and 9 column from | separated txt file using PowerShell

Issue I have Pipe separated data file with huge data and i want to remove 3,7, and 9 column. below script is working 100% fine. but its too slow its taking 5 mins for 22MB file. Adeel|01|test|1234589|date|amount|00|123345678890|test|all|01| Adeel|00|test|1234589|date|amount|00|123345678890|test|all|00| Adeel|00|test|1234589|date|amount|00|123345678890|test|all|00| Adeel|00|test|1234589|date|amount|00|123345678890|test|all|00|

Continue reading## [SOLVED] Why is random device creation expensive?

Issue C++11 supports pseudo-random number generation through the <random> library. I’ve seen multiple books which mention that it is quite expensive to keep constructing and destroying std::random_device, std::uniform_int_distribution<>, std::uniform_real_distribution<> objects, and they recommend to keep a single copy of these

Continue reading## [SOLVED] Get last conversations as admin in mongodb

Issue I have a Learning Management System (LMS) where students can ask/chat with admins for each lesson. As an Admin, I want to get last unseen chats from all lessons sorted by createdAt & seenByAdmin from dashboard. Here’s my Message

Continue reading## [SOLVED] Quickly apply a known sort order (old index -> new index mapping) to an array

Issue I am trying to performance tune a routine that needs to sort 8 large arrays "in tandem", where one of the arrays is the array to sort by. I’ve already taken care of sorting the first array using a

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