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Summarizing multiple columns with dplyr? [duplicate]
...brary(dplyr)
library(purrrlyr)
library(data.table)
library(bench)
set.seed(123)
n <- 10000
df <- data.frame(
a = sample(1:5, n, replace = TRUE),
b = sample(1:5, n, replace = TRUE),
c = sample(1:5, n, replace = TRUE),
d = sample(1:5, n, replace = TRUE),
grp = sample(1:3, n, replac...
How do I check if a C++ std::string starts with a certain string, and convert a substring to an int?
...only match at that position or earlier. For example:
std::string test = "0123123";
size_t match1 = test.rfind("123"); // returns 4 (rightmost match)
size_t match2 = test.rfind("123", 2); // returns 1 (skipped over later match)
size_t match3 = test.rfind("123", 0); // returns std::string::npos (i...
Java: How to set Precision for double value? [duplicate]
...ts.
If you only want to print, use it this way:
System.out.printf("%.2f",123.234);
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Renaming a virtualenv folder without breaking it
... using and so don't encounter the problem.
– CoderGuy123
Nov 4 '16 at 18:06
Scratch that! Today I ran into a problem: ...
Git - working on wrong branch - how to copy changes to existing topic branch
...
Sounds like all you need is the following:
git stash
git checkout branch123
git stash apply
Then you should be back on your own branch without touching the master branch.
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Checking if object is empty, works with ng-show but not from controller?
...wered May 8 '14 at 22:21
testing123testing123
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How to print formatted BigDecimal values?
...nts money, and I need to print its value in the browser in a format like $123.00 , $15.50 , $0.33 .
6 Answers
...
Creating PHP class instance with a string
...ther cool stuff you can do in php are:
Variable variables:
$personCount = 123;
$varname = 'personCount';
echo $$varname; // echo's 123
And variable functions & methods.
$func = 'my_function';
$func('param1'); // calls my_function('param1');
$method = 'doStuff';
$object = new MyClass();
$obj...
Spring mvc @PathVariable
...nt to write a url to fetch some order, you can say
www.mydomain.com/order/123
where 123 is orderId.
So now the url you will use in spring mvc controller would look like
/order/{orderId}
Now order id can be declared a path variable
@RequestMapping(value = " /order/{orderId}", method=RequestMe...
Regular Expression to reformat a US phone number in Javascript
...
Assuming you want the format "(123) 456-7890":
function formatPhoneNumber(phoneNumberString) {
var cleaned = ('' + phoneNumberString).replace(/\D/g, '')
var match = cleaned.match(/^(\d{3})(\d{3})(\d{4})$/)
if (match) {
return '(' + match[1] + ')...