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Can dplyr package be used for conditional mutating?
...tutorials, it is very common to have the need for calculating stuff for subsets of the data, but still wanting to keep the data complete.
– Javier Fajardo
Mar 15 '18 at 21:06
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Git Diff with Beyond Compare
... can be used to determine whether the merge was successful. If this is not set to true then the merge target file timestamp is checked and the merge assumed to have been successful if the file has been updated, otherwise the user is prompted to indicate the success of the merge.
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C++实现一款简单完整的聊天室服务器+客户端 - C/C++ - 清泛网 - 专注C/C++及内核技术
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return 0;
}
void* ListenThread(void*ps){
int s=*(int*)ps;
fd_set listenSet;
int sock;
struct sockaddr_in clientAddr;
struct timeval timeout;
while(!toStop){
FD_ZERO(&listenSet);
FD_SET(s,&listenSet);
timeout.tv_sec = 5;
timeout.tv_usec = 0;
int...
What does new self(); mean in PHP?
...statically and checks whether the static class has the variable $_instance set.
If it isn't, it initializes an instance of itself (new self()) and stores it in $_instance.
If you call className::getInstance() you will get one and the same class instance on every call, which is the point of the si...
What is the difference between char array and char pointer in C?
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why i can set char *name; name="123"; but can do the same with int type? And after using %c to print name , the output is unreadable string: �?
– TomSawyer
Apr 23 at 19:52
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Where can I learn how to write C code to speed up slow R functions? [closed]
...l and do not hold back. We know we are short documentation -- but a fresh set of eyes could help tremendously.
– Dirk Eddelbuettel
Nov 5 '10 at 14:50
6
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How do you determine what SQL Tables have an identity column programmatically
...BLE_TYPE (joining INFORMATION_SCHEMA.TABLES) for readibility of the result set.
– Diego Scaravaggi
Aug 28 '18 at 7:53
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How do I log ALL exceptions globally for a C# MVC4 WebAPI app?
...e I get the logID and pass it back so the user can add commentary), so I'm setting Result to a new ResponseMessageResult. This has been bugging me for a while, thanks.
– Brett
Sep 5 '14 at 23:41
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Django filter queryset __in for *every* item in list
...additional filter adds more joins, which should not be a problem for small set of categories.
There is the aggregation approach. This query would be shorter and perhaps quicker for a large set of categories.
You also have the option of using custom queries.
Some examples
Test setup:
class Pho...
Remove secure warnings (_CRT_SECURE_NO_WARNINGS) from projects by default in Visual Studio
Is there a way to set by default for all projects removing the precompiler secure warnings that come up when using functions like scanf(). I found that you can do it by adding a line in the project option or a #define _CRT_SECURE_NO_WARNINGS in the beginning of the code.
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