random

How can I draw a random sample from a dataset, proportionate to size, based on different proportions for each value of a factor variable, in R

倾然丶 夕夏残阳落幕 提交于 2021-01-01 17:51:31
问题 I want to draw a random sample from my dataset, using different proportions for each value of a factor variable, as well as using weights stored in some other column. dplyr solution in pipes will be preferred as it can be inserted easily in long code. Let's take the example of iris dataset. Species column is divided into three values 50 rows each. Let's also assume the sample weights are stored in column Sepal.Length . If I have to sample equal proportions (or equal rows) per species, the

How can I draw a random sample from a dataset, proportionate to size, based on different proportions for each value of a factor variable, in R

[亡魂溺海] 提交于 2021-01-01 17:51:16
问题 I want to draw a random sample from my dataset, using different proportions for each value of a factor variable, as well as using weights stored in some other column. dplyr solution in pipes will be preferred as it can be inserted easily in long code. Let's take the example of iris dataset. Species column is divided into three values 50 rows each. Let's also assume the sample weights are stored in column Sepal.Length . If I have to sample equal proportions (or equal rows) per species, the

Random numbers external sort

眉间皱痕 提交于 2021-01-01 06:47:45
问题 I need to write a program that generates N random numbers and write them to binary file in descending order. It should be done without using any of sorting algorithms that use main memory. This is what I've done so far: #include <iostream> #include <fstream> #include <ctime> #include <cstdlib> using namespace std; int main () { srand(time(0)); rand(); int N; do{ cout << "Unesite N: "; cin >> N; } while(N<=0); ofstream br("broj.dat", ios::binary | ios::trunc); for(int i = 0; i<N; i++){ int a =

Inverse normal random number generation in python?

感情迁移 提交于 2020-12-27 06:56:51
问题 I've used random.normal() in the past to generate a single number who, if called multiple times, in aggregate would create a bell curve distribution. What I'm trying to do now is to create the opposite / inverse, where the distribution is biased towards the extremes within a range? There are built in functions in excel that seem to do what I want. Is there a way to do it in python? Thank you 回答1: It appears you want a distribution with an "upside-down bell curve" compared to the normal

Inverse normal random number generation in python?

早过忘川 提交于 2020-12-27 06:55:20
问题 I've used random.normal() in the past to generate a single number who, if called multiple times, in aggregate would create a bell curve distribution. What I'm trying to do now is to create the opposite / inverse, where the distribution is biased towards the extremes within a range? There are built in functions in excel that seem to do what I want. Is there a way to do it in python? Thank you 回答1: It appears you want a distribution with an "upside-down bell curve" compared to the normal

Which Javascript I need for a carousel with random photos from specific folder?

百般思念 提交于 2020-12-27 06:44:47
问题 I have a problem that seems small, but it is no longer making me sleep at night, I am probably thinking about it too much and I have lost sight of the correct path! I'm using Bootstrap 4 as Framework. I have to insert an automatic, interaction-free, full-page Carousel that displays images in random order each time the page is refreshed. It has to get the images from a specific folder, because I have a large number of images. Anyone can help me with the Javascript that i need for do that??

Flutter : how to show next index after complete a specific logic in Swiper, where GridView also set in Swiper?

我只是一个虾纸丫 提交于 2020-12-26 12:05:57
问题 I'm trying to make a word game. First of all, the index will be white. if user Click the correct answer then index will be to green color and go to next screen, also index will be white in next screen.. again if user click incorrect answer then index will be to red color and don't let go to the next page until user put correct answer... i set a GridView in Swiper (Swiper took by importing, import 'package:flutter_swiper/flutter_swiper.dart';). and i want to show next index of Swiper after

Flutter : how to show next index after complete a specific logic in Swiper, where GridView also set in Swiper?

走远了吗. 提交于 2020-12-26 12:05:09
问题 I'm trying to make a word game. First of all, the index will be white. if user Click the correct answer then index will be to green color and go to next screen, also index will be white in next screen.. again if user click incorrect answer then index will be to red color and don't let go to the next page until user put correct answer... i set a GridView in Swiper (Swiper took by importing, import 'package:flutter_swiper/flutter_swiper.dart';). and i want to show next index of Swiper after

Generate random points on 10-dimensional unit sphere

我与影子孤独终老i 提交于 2020-12-26 04:28:34
问题 I need to generate a vector sampled uniformly with 10 directions (a collection of 10 random numbers) which lies over a unit sphere. So, the sum of the squares of the 10 values should be 1. This is the exact question for which I need to generate those points: Implement the Perceptron algorithm and run it on the following synthetic data sets in ℝ 10 : pick 𝑤∗ = [1,0,0,…,0]; generate 1000 points 𝑥 by sampling uniformly at random over the unit sphere and then removing those that have margin 𝛾

Generate random points on 10-dimensional unit sphere

纵饮孤独 提交于 2020-12-26 04:21:48
问题 I need to generate a vector sampled uniformly with 10 directions (a collection of 10 random numbers) which lies over a unit sphere. So, the sum of the squares of the 10 values should be 1. This is the exact question for which I need to generate those points: Implement the Perceptron algorithm and run it on the following synthetic data sets in ℝ 10 : pick 𝑤∗ = [1,0,0,…,0]; generate 1000 points 𝑥 by sampling uniformly at random over the unit sphere and then removing those that have margin 𝛾