Hey, I am building a mySQL table listing points in n-dimensions, each dimension being indexed. Given any point in the n-dimensional system, I would like to be able to output all of the other points in order of their distance from the chosen point. A simple solution would be to calculate distances from each point using the pythagorean ...
Hi, Let f transform one value to another, then I'm writing a function that repeats the transformation n times. I have come up with two different ways: One is the obvious way that literally applies the function n times, so repeat(f, 4) means x → f(f(f(f(x)))) The other way is inspired from the fast method for powering, which means div...
I have a process that consolidates 40+ identically structured databases down to one consolidated database, the only difference being that the consolidated database adds a project_id field to each table. In order to be as efficient as possible, I'm try to only copy/update a record from the source databases to the consolidated database ...
Based on this older thread, it looks like the cost of list functions in Python is: Random access: O(1) Insertion/deletion to front: O(n) Insertion/deletion to back: O(1) Can anyone confirm whether this is still true in Python 2.6/3.x? ...
Hello everyone. I have written a Winform application in C#. How can I check the performance of my code. By that I mean, how can I check which forms references are active at a given time or event, so that I can remove them if they are not required (make them available for garbage collection). Is there a way to do it using VS 2005 or any f...
Is there a more "R-minded" way to dichotomise efficiently? Thanks. y<-c(0,3,2,1,0,0,2,5,0,1,0,0);b<-vector() for (k in 1:length(y)) { if (y[k] == 0) b[k] = 0 else b[k] = 1 } y;b ...
I want to iterate over the intersection of n sub-iterators. Each sub-iterator is sorted from GREATEST TO LEAST, and the values must be accessed sequentially. Assume no duplicate values. So far I have thought of two approaches using a heap/priority queue, but I'm struggling to figure out which is more efficient - it seems like it may b...
Hello Stack Overflow Community, I have a list where I want to replace values with None where condition() returns True. [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10] For example, if condition checks bool(item%2) should return: [None, 1, None, 3, None, 5, None, 7, None, 9, None] What is the most efficient way to do this? ...
The idea was to create/populate a perfmon counter with the # of files in a directory. Apparently FileNet (a program) uses a given directory as a queue, and gets hung up sometimes. Hence the need to monitor the # of files that are stacking up... Now most of you will probably LOL your asses off at my spider web of "if/then" statements, ...
So LinkedIn has this cool feature in which while visiting some user's profile, linkedin prompts how you are connecting to that user through the network. Assuming that the visitor and the profile owner are two nodes of a graph where the nodes represent users and edge represents friendship, a simple solution could be a bfs starting fr...
I'm creating a list of a month's worth of dates. I'm wondering what will be more efficient List<DateTime> GetDates(DateTime StartDay) { List<DateTime> dates = new List<DateTime>(); int TotalDays=StartDay.AddMonths(1).AddDays(-1).Day; for (int i=1; i<TotalDays; i++) { dates.Add(new DateTime(StartDay.Year, StartDay.Month, i)); ...
Hi All, I'm wondering what benefits this code has: private int _TestID; public int TestID { get { return _TestID; } set { if(_TestID != value) { _TestID = value; } } } vs. this: private int _TestID; ...
Hi, A theoretical question not depending on implementation, how much of a decrease in performance is 1024bit vs 4096bit RSA? Thanks ...
I've seen statements like this if(SomeBoolReturningFunc()) { //do some stuff //do some more stuff } and am wondering if putting a function in an if statement is efficient, or if there are cases when it would be better to leave them separate, like this bool AwesomeResult = SomeBoolReturningFunc(); if(AwesomeResult) { //do ...
I read this SO post after I wrote out the title but still decided to go through with the question on bug-proof implementations of equals in Java. This is my normal implementation @Override public boolean equals(Object o){ if(o == null) return false; if(o instanceof CompositePk == false) return false; ...
This method is a bottleneck in my program. (Or, it is at least where most of the time is being spent.) Its purpose is to calculate the similarity between two strings based on the way characters occur in both, or occur in one or not the other. The code is correct, but I would like to optimize it. Do you see any inefficiencies, bad pract...
I'd like two different HTML elements that are at the same nesting level to have identical CSS property values. Is there an alternative to this wasteful syntax? .level1 .level2 .level3 element1 { /*rules*/ } .level1 .level2 .level3 element2 { /*rules*/ } I was thinking .level1 .level2 .level3 element1, .level1 .level2 .level3 element2...
Problem description There are different categories which contain an arbitrary amount of elements. There are three different attributes A, B and C. Each element does have an other distribution of these attributes. This distribution is expressed through a positive integer value. For example, element 1 has the attributes A: 42 B: 1337 C: ...
One of my team mates was held up for mockery by the team leads for preferring to run maven as: $ mvn clean $ mvn install The discussion by the team leaders was about efficiency and speed of work & someone brought up the issue that person X is continuing to split $ mvn clean install into 2 separate commands. I know, I know that lif...
Hello, I'm trying to archive records from a table in a database to an identical table in an archive database. I need to be able to do an insert for all records with a date greater than three years ago, and then delete those rows. However, this table has millions of records which are live, so I want to run this in a loop of roughly 100 ...