Data dodania Pytanie
2017-09-28 15:09 postgres, server closed the connection unexpectedly via VBS »
I get this error: "server closed the connection unexpectedly This probably means the server terminated abnormally before or while processing the requ...
(1) odpowiedzi
2017-09-28 13:09 Fast copy every second byte to new memory area »
I need a fast way to copy every second byte to a new malloc'd memory area. I have a raw image with RGB data and 16 bits per channel (48 bit) and want ...
(1) odpowiedzi
2017-09-28 11:09 Faster way to concatenate vectors repeatedly »
Is there a faster way to concatenate matrix like this code below? These lines of code will be called thousands of times, thus it's very time consuming...
(1) odpowiedzi
2017-09-27 20:09 Create efficient week over week calculation with subsetting »
In my working dataset, I'm trying to calculate week-over-week values for the changes in wholesale and revenue. The code seems to work, but my estimat...
(2) odpowiedzi
2017-09-27 13:09 What is a fast integer ? What defines how fast an integer is? »
I am not a C++ expert but I started learning through www.learncpp.com which is great btw, and I suggest for any new c++ learner and in this topic: ht...
(2) odpowiedzi
2017-09-27 12:09 Do multiple classes on html tag always affect rendering performance? »
Came across an interesting video about debugging rendering performance in Chrome devtools. In his lesson Umar identifies the changing of a CSS class o...
(0) odpowiedzi
2017-09-26 15:09 PostgreSQL using BitmapAnd instead of composite index »
I have table2 and I'm limiting my result by date range date_col and integer column col1. I get different plans between using BETWEEN and IN() for date...
(0) odpowiedzi
2017-09-26 10:09 Complexity of Array methods »
In a team project we need to remove the first element of an array, thus I called Array.prototype.shift(). Now a guy saw Why is pop faster than shift?,...
(2) odpowiedzi
2017-09-26 08:09 Removing Objects in Java ArrayList - Time Consumption »
I'm trying to remove 140,000 objects from an ArrayList of size 7,140,000. I expected this would take seconds (if that), but instead Java is taking mu...
(2) odpowiedzi
2017-09-26 04:09 For C++ Vector3 utility class implementations, is array faster than struct and class? »
just out of curiosity, I implemented vector3 utilities in 3 ways: array (with a typedef), class and struct This is the array implementation: typedef...
(2) odpowiedzi
2017-09-25 16:09 Data frame to nested list »
I have a dataframe which I read from a .csv file and looks like this: job name `phone number` <chr> <chr> ...
(2) odpowiedzi
2017-09-25 15:09 Force GIN index scan in postgresql 9.4 »
I'm having a table of locations(29 million rows approx) Table "public.locations" Column | Type| Modifiers ------------------------------------+...
(1) odpowiedzi
2017-09-25 10:09 Reduce memory usage of Android applications »
I am developing a simple Android application which displays a list of users by obtaining their details along with a profile picture from a server. The...
(1) odpowiedzi
2017-09-25 06:09 com.sun.mail.smtp.SMTPSendFailedException: 550 Access denied - Invalid HELO name (See RFC2821 4.1.1.1) »
public static void main(String [] args){ String to="xyz@gmail.com";//change accordingly final String user="abc@gmail.com";//change accordingl...
(1) odpowiedzi
2017-09-24 22:09 C# calling native code is faster than native calling native »
While doing some performance testing, I've run into a situation that I cannot seem to explain. I have written the following C code: void multi_arr(i...
(0) odpowiedzi
2017-09-24 15:09 How to measure the quality of my code? »
I have some experience with coding but one of the biggest questions which annoying me is how to improve my code. I every time check the complexity, r...
(3) odpowiedzi
2017-09-24 10:09 React bind method »
In React.js you better define your method binding in the constructor like this: constructor(props){ this.poo = this.poo.bind(this); } it's better...
(1) odpowiedzi
2017-09-22 19:09 Julia - why are loops faster »
I have a background in MATLAB so I have the tendency to vectorize everything. However, in Julia, I tested these two functions: function testVec(n) ...
(2) odpowiedzi
2017-09-22 18:09 Python: Is it possible to make this tail-recursion factorial even faster? »
I'm making a utilities class for an application which involves combinatorics. I've made two factorial funcion which tail recursion. The second one im...
(1) odpowiedzi
2017-09-22 00:09 Performance of struct tuples »
The following F# program defines a function that returns the smaller of two pairs of ints represented as struct tuples and it takes 1.4s to run: let ...
(1) odpowiedzi
2017-09-21 23:09 Python - Most efficient way to define a piecewise function »
I have a piecewise mathematical function that needs to be evaluated a lot of times, as a subfunction in quad and curve_fit routines. In trying to impr...
(0) odpowiedzi
2017-09-21 10:09 c# Fastest string search in all files »
Problem (Check edit for clarifications) I have a list of about 1500 strings and for each of these strings I have to check if any of the files in a di...
(5) odpowiedzi
2017-09-21 06:09 Quotes and curly brakets around variables. Which one makes the fastest Mysql query? »
We know that single quotes in PHP is faster than double quotes so $foo = 'lorem ipsum'; is faster than $foo = "lorem ipsum";. But what about in Mysql...
(2) odpowiedzi
2017-09-20 21:09 Uniformly partition PySpark Dataframe by count of non-null elements in row »
I know there are a thousand questions out there related to how best to partition your DataFrames or RDDs by salting keys, etc., but I think this situa...
(1) odpowiedzi
2017-09-20 18:09 Performance Trace of Program »
I have a short-running program and once I run it, I need to record its CPU utilization and at the end I need to know its total instruction count. I we...
(1) odpowiedzi
2017-09-20 16:09 Is it a good idea to use the Google CDN for jQuery under HTTP2? »
Currently my website uses the Google CDN for jquery: <script src="//ajax.googleapis.com/ajax/libs/jquery/1.10.2/jquery.min.js"></script> ...
(0) odpowiedzi
2017-09-19 14:09 Generating a random (equal probability) combination with replacement »
I want to generate one random combination out of all possible combinations_with_replacement. The tricky bit is that I want each of the possible outcom...
(2) odpowiedzi
2017-09-19 14:09 The numba fibonacci function is slower and does not return the same result »
This code return slow and with different output: from numba import jit from timeit import default_timer as timer def fibonacci(n): a, b = 1, 1 ...
(2) odpowiedzi
2017-09-19 08:09 c - Are defined values slower than hard-coded numbers »
this question might appear dumb to you but I couldn't find an answer to it and I want to be sure that it works as I think. Recently I came across thi...
(3) odpowiedzi
2017-09-18 20:09 Optimizing function speed on 3D array »
I am applying a user-defined function to individual cells of a 3D array. The contents of each cell are one of the following possibilities, all of whi...
(1) odpowiedzi
2017-09-18 19:09 python numpy speed up 2d duplicate search »
I need to find duplicates in a 2d numpy array. As a result i want a list of the same length as the input which points to the first occurrence of the c...
(3) odpowiedzi
2017-09-18 14:09 Regex crossword solver »
Following Find string to regular expression programmatically?, we assume that it takes linear time to find a string that matches a regex. My intiution...
(1) odpowiedzi
2017-09-17 19:09 Troubleshooting Major Garbage Collection Cause »
I have a Java application running on Open SDK 1.7.0_95 64 bin environment and I am seeing two major garbage collection every hour which is hitting app...
(1) odpowiedzi
2017-09-17 09:09 Elegant way to complete a parallel operation on two arrays of unequal lengths »
I want to write a function in numba that runs a math operation on 2 arrays, and accommodate for when both arrays don't have the same element count. S...
(2) odpowiedzi
2017-09-17 08:09 Make sampling run faster »
I need to extract 2Mil observations out of 23Mil data set. Using the code below it takes a lot of time to get it done. On Xeon CPU with 16GB RAM it's ...
(3) odpowiedzi