sample Questions
2
Solved
Is it possible to extend the sample function in R to not return more than say 2 of the same element when replace = TRUE?
Suppose I have a list:
l = c(1,1,2,3,4,5)
To sample 3 elements with repl...
1
Solved
[Edit] I am not sure why I got a minus vote on this. I looked online but did not find much about what this setting does and now I got a great explanation below by Rob Napier, so I am quite happy. A...
Yehudi asked 16/7, 2023 at 11:34
2
I'm trying to use data.table/tidyverse to efficiently sample at two levels:
Level 1 is Hospital ID ( hospital_id )
Level 2 is Doctor ID ( doctor_id )
I need to first sample with replacement $N$ hos...
Triglyceride asked 7/7, 2023 at 5:26
1
I'm having a problem thats limiting me quite a bit. We are trying to sample our data by grouping time. We have millions of points and want to fetch every Nth point in a given interval. We have impl...
Painkiller asked 24/10, 2017 at 8:28
7
Solved
I want to sample rows from a data frame using unequal sample sizes from each group.
Let's say we have a simple data frame grouped by 'group':
library(dplyr)
set.seed(123)
df <- data.frame(group...
3
Solved
Why does the rdd.sample() function on Spark RDD return a different number of elements even though the fraction parameter is the same? For example, if my code is like below:
val a = sc.parallelize(...
Hiragana asked 29/9, 2015 at 6:55
3
Is it possible to import a Confluence xml dump into Mediawiki? If so, any guidance will be appreciated.
Thanks for you assistance!
Periphrasis asked 20/7, 2012 at 14:32
3
Solved
I have df and I'd like to make some sampling from it with respect to distribution of some variable. Let's say df['type'].value_counts(normalize=True) returns:
A 0.3
B 0.5
C 0.2
I'd like to make so...
4
Solved
How to generate a random (but unique and sorted) list of a fixed given length out of numbers of a given range in Python?
Something like that:
>>> list_length = 4
>>> values_rang...
28
I've just started using R and I'm not sure how to incorporate my dataset with the following sample code:
sample(x, size, replace = FALSE, prob = NULL)
I have a dataset that I need to put into a...
9
Solved
I have a data frame made by almost 50,000 rows spread in 15 different IDs (every ID has thousands of observations). Data frame looks like:
ID Year Temp ph
1 P1 1996 11.3 6.80
2 P1 1996 9.7 6.90
3 ...
1
Solved
using PyPlot
n = 50
u = range(0,stop=2*π,length=n);
v = range(0,stop=π,length=n);
x = cos.(u) * sin.(v)';
y = sin.(u) * sin.(v)';
z = ones(n) * cos.(v)';
scatter3D(vec(x),vec(y),vec(z);c="r...
5
Solved
HTTP/1.1 specifies that a response sent as Transfer-Encoding: chunked can include optional trailers (ie. what would normally be sent as headers, but for whatever reason can't be calculated before t...
Introspect asked 14/11, 2012 at 0:40
1
Solved
I want to split an audio file into several equal-length segments using FFmpeg. I want to specify the general segment duration (no overlap), and I want FFmpeg to render as many segments as it takes ...
5
Solved
I have a pandas DataFrame with 100,000 rows and want to split it into 100 sections with 1000 rows in each of them.
How do I draw a random sample of certain size (e.g. 50 rows) of just one of the 10...
5
Solved
Is there a pythonic way to select N consecutive elements from a list or numpy array.
So Suppose:
Choice = [1,2,3,4,5,6]
I would like to create a new list of length N by randomly selecting element...
4
I am trying to read an image in opencv python
import cv2
import numpy as np
# Read images
image=cv2.imread(cv2.samples.findFile("lena.jpg"))
cv2.imshow("image",image)
cv2.waitKey(0)
and it giv...
2
Solved
Given a dataset like this:
import pandas as pd
rows = [{'key': 'ABC', 'freq': 100}, {'key': 'DEF', 'freq': 60},
{'key': 'GHI', 'freq': 50}, {'key': 'JKL', 'freq': 40},
{'key': 'MNO', 'freq': 13}...
Humbert asked 9/12, 2020 at 17:56
4
If I want to randomly select some samples from different groups I use the plyr package and the code below
require(plyr)
sampleGroup<-function(df,size) {
df[sample(nrow(df),size=size),]
}
iris...
5
Solved
I'm in my OPENCV_ROOT folder and running the following command in Win-x64:
opencv_createsamples -bgcolor 0 -bgthresh 0 -maxxangle 1.1 -maxyangle 1.1
maxzangle 0.5 -maxidev 40 -w 80 -h 40
-img AB...
Equipollent asked 24/3, 2014 at 13:0
3
Solved
I want to randomize/shuffle a vector. Some of the vector elements are identical. After shuffling, identical elements should have a minimum distance of three (i.e. two other elements should be betwe...
4
Solved
When I try to build the BreakfastFinder Sample Code from Apple, it will build it for Simulator but not for my iPhone X with IOS 13(Public Beta 3).
I tried Unpair and repair the Device, switching t...
Mcbroom asked 22/7, 2019 at 7:48
7
Solved
How can I select random sample from DBpedia using the sparql endpoint?
This query
SELECT ?s WHERE { ?s ?p ?o . FILTER ( 1 > bif:rnd (10, ?s, ?p, ?o) ) } LIMIT 10
(found here)
seems to work...
3
Solved
When running the sample after creating google-service.json, the app crashes when trying to get database reference in SignInActivity
mDatabase = FirebaseDatabase.getInstance().getReference();
Cra...
Lauder asked 21/5, 2016 at 13:50
2
Solved
I used this code to create a random sample for the numbers 0 to 49. Now I want to create a random sample for a custom set of values. For example: select a sample of 5 from [1, 2, 3, 4, 9, 10, 11, 1...
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