We have an SQL Server that gets daily imports of data files from clients. This data is interrelated and we are always scrubbing it and having to look for suspect duplicate records between these files. Finding and tagging suspect records can get pretty complicated. We use logic that requires some field values to be the same, allows som...
I'm looking for references to algorithms for plotting on a mechanical pen plotter. Specifically, I have a list of straight vectors, each representing a line to be plotted. First I want to remove duplicate vectors, so each line is only plotted once. That's easy enough. Second, there are many vectors that intersect, sometimes at endpoin...
I'm trying to do a simple genomic track intersection in R, and running into major performance problems, probably related to my use of for loops. In this situation, I have pre-defined windows at intervals of 100bp and I'm trying to calculate how much of each window is covered by the annotations in mylist. Graphically, it looks somethi...
I wondering if there is a faster (GPU time) way to draw a full-screen quad in OpenGL: NewList(); PushMatrix(); LoadIdentity(); MatrixMode(PROJECTION); PushMatrix(); LoadIdentity(); Begin(QUADS); Vertex(-1,-1,0); Vertex(1,-1,0); Vertex(1,1,0); Vertex(-1,1,0); End(); PopMatrix(); MatrixMode(MODELVIEW); PopMatrix(); EndList(); note th...
I wondering if there is a way to optimize this vertex shader. This vertex shader projects (in the light direction) a vertex to the far plane if it is in the shadow. The aim of this shader is to create a shadow volume object that enclose the shadow of the object itself. void main(void) { vec3 lightDir = (gl_ModelViewMatrix * gl_Vertex ...
This question is mostly academic. I ask out of curiosity, not because this poses an actual problem for me. Consider the following incorrect C program. #include <signal.h> #include <stdio.h> static int running = 1; void handler(int u) { running = 0; } int main() { signal(SIGTERM, handler); while (running) ; pr...
Assume the following: we have class B, which is a private class nested inside class A. There isn't any class inheriting from class B. The question is: will the compiler automatically mark class B as Sealed? (NonInheritable in VB). Is there any good reason for the compiler not to mark class B as sealed? My line of thought is this: since...
Consider the bellow code. This code is supposed to be processing data at a fixed rate, in one second batches, It is part of an overal system and can't take up too much time. When running over 100 lots of 1 seconds worth of data the program takes 35 seconds (or 35%), executing this function in a loop. The test loop is timed specifically ...
I'm generally not a fan of microbenchmarks. But this one has a very interesting result. http://ernestdelgado.com/archive/benchmark-on-the-floor/ It suggests that Math.floor is the SLOWEST way to calculate floor in Javascript. ~~n, n|n, n&n all being faster. This seems pretty shocking as I would expect that people implementing Javascri...
A recurring analysis paradigm I encounter in my research is the need to subset based on all different group id values, performing statistical analysis on each group in turn, and putting the results in an output matrix for further processing/summarizing. How I typically do this in R is something like the following: data.mat <- read.c...
hello all i have the following piece of code, that im looking forward to optimize, since i'm consuming gobs of memory this routine is heavily used first optimization would be to move the stringbuilder construction out of the download routine and make it a field of the class, then i would clear it inside the routine can you please sugge...
I have two tables, news and news_views. Every time an article is viewed, the news id, IP address and date is recorded in news_views. I'm using a query with a subquery to fetch the most viewed titles from news, by getting the total count of views in the last 24 hours for each one. It works fine except that it takes between 5-10 seconds ...
The C++ comma operator is used to chain individual expressions, yielding the value of the last executed expression as the result. For example the skeleton code (6 statements, 6 expressions): step1; step2; if (condition) step3; return step4; else return step5; May be rewritten to: (1 statement, 6 expressions) return s...
I try to get the list of images in Amazon EC2 inside the Google datastore. I want to realize this with a cron job inside the GAE. class AmazonEC2uswest(db.Model): ami = db.StringProperty(required=True) mani = db.StringProperty() typ = db.StringProperty() arch = db.StringProperty() state = db.StringProperty() owne...
this query gets the dominating sets in a network. so for example given a network A<----->B B<----->C B<----->D C<----->E D<----->C D<----->E F<----->E it returns B,E B,F A,E but it doesn't work for large data because i'm using string methods in my result. i have been trying to remove the string methods and re...
Are there standard optimization tricks for Objective-C to make for faster execution along the lines of "inlining" frequent methods as in C++ or the "g++ -fast" tag? Edit: Does anyone have a short example using SEL and IMP when theMethod has two (or more) integers for input? ...
Hello - I am trying to run Osiexample.cpp from COIN-OR (open-source software for numerical optimization) in MS Visual Studio 2008 and get the error message below. Linking... CoinOR Example.obj : error LNK2019: unresolved external symbol "public: __thiscall OsiClpSolverInterface::OsiClpSolverInterface(void)" (??0OsiClpSolverInterface@@Q...
I have converted my Datatable to json string use the following method... public string GetJSONString(DataTable Dt) { string[] StrDc = new string[Dt.Columns.Count]; string HeadStr = string.Empty; for (int i = 0; i < Dt.Columns.Count; i++) { StrDc[i] = Dt.Columns[i].Caption; HeadStr += "\"" + StrDc[i] + "\"...
I jave a 2D array like this, just like a matrix: {{1, 2, 4, 5, 3, 6}, {8, 3, 4, 4, 5, 2}, {8, 3, 4, 2, 6, 2}, //code skips... ... } (The Array is not sorted) I want to get all the "4" position, instead of searching the array one by one, and return the position, how can I search it faster / more efficient? thz in advance. ...
I need help in optimizing the following query. It is taking a long time to finish. It takes almost 213 seconds . because of some constraints, I can not add an index and have to live with existing ones. INSERT INTO temp_table_1 ( USER_ID, role_id, participant_code, status_id ) WITH A AS (SELECT USER_ID user_id,ROLE_ID, STATUS_ID,parti...