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How do I install an R package from source?
...hen use install.packages() and set the repos=NULL:
install.packages(path_to_file, repos = NULL, type="source")
Where path_to_file would represent the full path and file name:
On Windows it will look something like this: "C:\\RJSONIO_0.2-3.tar.gz".
On UNIX it will look like this: "/home/blah/R...
Conveniently Declaring Compile-Time Strings in C++
...
I haven't seen anything to match the elegance of Scott Schurr's str_const presented at C++ Now 2012. It does require constexpr though.
Here's how you can use it, and what it can do:
int
main()
{
constexpr str_const my_string = "Hello, world!";
static_assert(my_string.size() == 13,...
How can I check if a Perl array contains a particular value?
...
Simply turn the array into a hash:
my %params = map { $_ => 1 } @badparams;
if(exists($params{$someparam})) { ... }
You can also add more (unique) params to the list:
$params{$newparam} = 1;
And later get a list of (unique) params back:
@badparams = keys %params;
...
第一个Hello,OS World操作系统 - 操作系统(内核) - 清泛网 - 专注C/C++及内核技术
第一个Hello,OS World操作系统hello_os_word_my_first_os操作系统并非我们想象中的深不可测、遥不可及，只要你对它感兴趣并随我一起动手实践，你也能开发出属于自己的os。本文通过一个最简单的os，完成Hello, OS World文字的输出来演示os...
Does Swift support reflection?
...Have a look the answer stackoverflow.com/a/25345461/292145 to find out how _stdlib_getTypeName can help.
– Klaas
Aug 17 '14 at 1:14
1
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Best way to do multi-row insert in Oracle?
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This works in Oracle:
insert into pager (PAG_ID,PAG_PARENT,PAG_NAME,PAG_ACTIVE)
select 8000,0,'Multi 8000',1 from dual
union all select 8001,0,'Multi 8001',1 from dual
The thing to remember here is to use the from dual statement.
(source)
...
Linq to Sql: Multiple left outer joins
...SQL:
Dim db As New ContractDataContext()
Dim query = From o In db.Orders _
Group Join v In db.Vendors _
On v.VendorNumber Equals o.VendorNumber _
Into ov = Group _
From x In ov.DefaultIfEmpty() _
Group Join s In db.Status _
On...
How to join two sets in one line without using “|”
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You can use union method for sets: set.union(other_set)
Note that it returns a new set i.e it doesn't modify itself.
share
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Is there any Rails function to check if a partial exists?
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Currently, I'm using the following in my Rails 3/3.1 projects:
lookup_context.find_all('posts/_form').any?
The advantage over other solutions I've seen is that this will look in all view paths instead of just your rails root. This is important to me as I have a lot of rails engines.
This a...
How to tell if a tag failed to load
... };
var fail = function () {
if (!scriptTag.__es) {
scriptTag.__es = true;
scriptTag.id = 'failed';
args.failure(scriptTag);
}
};
scriptTag.onload = function () {
...