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Split delimited strings in a column and insert as new rows [duplicate]
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Here is another way of doing it..
df <- read.table(textConnection("1|a,b,c\n2|a,c\n3|b,d\n4|e,f"), header = F, sep = "|", stringsAsFactors = F)
df
## V1 V2
## 1 1 a,b,c
## 2 2 a,c
## 3 3 b,d
## 4 4 e,f
s <- strsplit(df$V2, split = ",")
data.frame(V1 = rep(df$V1, sapply(s,...
How to write the Fibonacci Sequence?
...nstead of returning the Fibonacci numbers between a range (ie. startNumber 1, endNumber 20 should = only those numbers between 1 & 20), I have written for the program to display all Fibonacci numbers between a range (ie. startNumber 1, endNumber 20 displays = First 20 Fibonacci numbers). I thought I...
Moving decimal places over in a double
So I have a double set to equal 1234, I want to move a decimal place over to make it 12.34
9 Answers
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How can I apply a function to every row/column of a matrix in MATLAB?
...an apply a function to every item in a vector by saying, for example, v + 1 , or you can use the function arrayfun . How can I do it for every row/column of a matrix without using a for loop?
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App Inventor 2 数学代码块 · App Inventor 2 中文网
...最多的元素 (mode)
案例：指定将二进制的某一位(Bit)改为1
案例：指定将二进制的某一位(Bit)改为0
基础数字块 ( 0 )
进制数字块 ( 0 )
等于 ( = )
不等于 ( ≠ )
大于 ( > )
大于等于 ( ≥ )
小于 ( < )
小于等于 ( ≤ )
加 (...
How to sort an array in descending order in Ruby
... Here's what I found out:
#!/usr/bin/ruby
require 'benchmark'
ary = []
1000.times {
ary << {:bar => rand(1000)}
}
n = 500
Benchmark.bm(20) do |x|
x.report("sort") { n.times { ary.sort{ |a,b| b[:bar] <=> a[:bar] } } }
x.report("sort reverse") { n.times ...
Why is SSE scalar sqrt(x) slower than rsqrt(x) * x?
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216
sqrtss gives a correctly rounded result. rsqrtss gives an approximation to the reciprocal, acc...
Check if at least two out of three booleans are true
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【HarmonyOS】真机测试ble - HarmonyOS NEXT - 清泛IT社区，为创新赋能！
[2:01:15 PM] YAIL[254]: (begin (require <com.google.youngandroid.runtime>) (process-repl-input "P:)R:yv~...
[2:01:15 PM] → SimpleYail 执行
[2:01:15 PM] [YAIL] 解析 YAIL (244 chars)
[2:01:15 PM] [YAIL] 解析得到 1 个顶层表达式
[2:01:15 PM] [YAIL] 执行[0]: (be...
MongoDB sort排序、index索引教程 - 大数据 & AI - 清泛网 - 专注C/C++及内核技术
...排序，sort()方法可以通过参数指定排序的字段，并使用 1 和 -1 来指...MongoDB sort排序
在MongoDB中使用使用sort()方法对数据进行排序，sort()方法可以通过参数指定排序的字段，并使用 1 和 -1 来指定排序的方式，其中 1 为升序排列，-...