"On-line" (iterator) algorithms for estimating statistical median, mode, skewness, kurtosis?

Is there an algorithm to estimate the median, mode, skewness, and/or kurtosis of set of values, but that does NOT require storing all the values in memory at once? I'd like to calculate the basic...

How to Correctly Use Lists in R?

Brief background: Many (most?) contemporary programming languages in widespread use have at least a handful of ADTs [abstract data types] in common, in particular, string (a sequence comprised of...

OpenMP: poor performance of heap arrays (stack arrays work fine)

I am a fairly experienced OpenMP user, but I have just run into a puzzling problem, and I am hopeful that someone here could help. The problem is that a simple hashing algorithm performs well for...

Hash function for a string

We are currently dealing with hash function in my class. Our instructor asked us to a hash function on the internet to compare to the two we have used in our code. The first one: int...

What's the difference between __builtin__ and __builtins__?

I was coding today and noticed something. If I open a new interpreter session (IDLE) and check what's defined with the dir function I get this: $ python >>> dir() ['__builtins__', '__doc__',...

MD5 Script and grep cmd

I found this neat little script on the Ubuntu website. The script verifies contents of CD by comparing it to an MD5 sum of an iso(9660) file. I don't understand why the script parses the string...

Two Sum: How is the solution with O(1) space complexity implemented?

The classical Two Sum problem is described in LeetCode. I know how to solve it with a hash table, which results in O(n) extra space. Now I want to solve it with O(1) space, so I'll first sort the...

Docker - Mac OSX Ubuntu fails on apt-get update

I'm using Ubuntu Docker image: ubuntu:14.04 I want to update my tree using: RUN apt-get update But i'm keep getting this error: W: GPG error: http://archive.ubuntu.com trusty Release: The...

solving the 2-sum algorithm in javascript

I'm trying to write a simple solution to the 2-Sum problem in Javascript. The problem goes: given an array of n integers and a target sum, determine what combinations of two integers will sum to...

Docker "ERROR: could not find an available, non-overlapping IPv4 address pool among the defaults to assign to the network"

I have a directory apkmirror-scraper-compose with the following structure: . ├── docker-compose.yml ├── privoxy │   ├── config │   └── Dockerfile ├──...

How to create a list of string with the Prelude.functions?

I look for something equivalent to what we can have in Python doing this:: >>> print([func for func in dir(__builtins__) if func[0].islower()]) ['abs', 'all', 'any', 'ascii', 'bin', 'bool',...

How to send FIX logon message with Python to GDAX/Coinbase

I'm trying to establish a FIX 4.2 session to fix.gdax.com (docs: https://docs.gdax.com/#fix-api or https://docs.prime.coinbase.com/?python#logon-a) using Python 3.5 and stunnel. Everything is...

mysql has gone away and tuning mysql database

i have a mysql database that crashes about 1 time a day with error mysql server has gone away. timeout is 28800 sec and I set max_allowed_packet to 1024M but i have still the problem. I read in...

Static global variables in Go

I am new in Go language and I need some help. I have declared a global variable but the problem is that it does not keep its value. It would be solved with a static variable but no such variables...

mysql crashing with "mysqld got signal 11"

I'm running application which reading and writing data with mysql database. I'm having both mysql ndbclustr and master master replication in same database. (bcoz of master master replication...

C Segmentation fault malloc.c: No such file or directory

Here is my code: // Implements a dictionary's functionality #include <stdbool.h> #include <stdio.h> #include <cs50.h> #include <ctype.h> #include <string.h> #include <strings.h> #include...

How do I install ubuntu packages in singularity image?

I work on a CentOS 6.6 system. I have a writeable singularity ubuntu 16.04 image, that I know that I can in fact write to: [[email protected]]# whoami root [[email protected]]# singularity shell...

How to change the key in an unordered_map?

I need to use a data structure which supports constant time lookups on average. I think that using a std::unordered_map is a good way to do it. My data is a "collection" of...

Android - SMS Retriever API - Computing app's hash string problem

I am really new in Android and I am trying to implement the SMS Retriever API for using OTP in my app. I am following this...

Mysql DDL query stuck in Waiting for table metadata lock when wrapped in transaction

This is a random behavior(didn't reoccur after restarting the mysql session) that when I wrapped the DDL query in a transaction T1 and at same time I initiate another transaction T2 with a select...

How to properly clone and update the IDs of Materialize select and pickers?

I'm cloning a block of Materialize form elements including a couple of selects, a time picker and textarea with a button click event. Current code uses a counter to increment the id and label for....

How do I implement double sum (No Hash - Just using my Array code)?

I'm trying to do a two sum problem using eclipse. I want to use an array and have the program do a standard recursion to see if any of the integers in my array listed below can add together to...

Failed to fetch ........... Hash Sum mismatch

Environment OS: Windows 10 Docker Version: 2.1.0.3 Stable Desktop Community Docker Compose Version: 1.24.1 Dockerfile FROM postgres:11 COPY ./99fixbadproxy...

Unable to build since upgrading from Angular 9.17 to 9.19

I upgraded from Angular 9.17 to 9.19 and now ng build fails with the following error complaining about a variable declaration in both @types/node and zone.js: ERROR in...

20% CPU usage when completely idle in RDS MySQL5.7 T3.xlarge instance

I'm currently using MySQL 5.7 RDS T3.xlarge instance(4 vCPU and 16G RAM) but have 20% CPU usage when the instance is idle completely. There is no any running queries and functions or triggers at...

Why is "Hash Sum mismatch" when installing nodejs on vagrant box ubuntu/bionic64

I'm newbie of using Vagrant. Recently I have an project required Nodejs version 12.x, I decided start with vagrant project, but unfortunately getting trouble while installing. I using the same...

SHA-256 with RSA Encryption

I am trying to manually verify the digital signature of a self signed certificate. SHA-256 RSA certified. As I understand it, the digital signature is verified using the formula s^e mod m. At the...

Android Facebook Share Dialog Blocks Login Due To Embedded Browser

I am using the cordova-plugin-facebook-connect plugin to launch the share dialogs from Facebook. iOS is working great, and Android is working great when the app is installed. On Android, if the...

AttributeError: module 'm5' has no attribute 'main'

I'm going through the gem5 tutorial and trying to run gem5 with the following script in Ubuntu 20.04: build/X86/gem5.opt configs/learning_gem5/part1/simple.py This is a link to the...

Wrong Complexity Calculation for Hash Tables?

I was reading: https://www.geeksforgeeks.org/given-an-array-a-and-a-number-x-check-for-pair-in-a-with-sum-as-x/ I think there is a mistake with calculating the time complexity for Method2...