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How do I delete rows in a data frame?
... :
mydata[-seq(2, nrow(mydata), by = 2) , ]
Or if you want to subset by selecting odd numbers:
mydata[which(1:nrow(mydata) %% 2 == 1) , ]
Or if you want to subset by selecting odd numbers, version 2:
mydata[which(1:nrow(mydata) %% 2 != 0) , ]
Or if you want to subset by filtering even numbe...
Scheduling R Script
...g go to
**TOOLS -> ADDINS ->BROWSE ADDINS ->taskscheduleR -> Select it and execute it.**
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Maven2: Missing artifact but jars are in place
...s of turning it off and on again.
Try right-clicking on the project and selecting Maven->Update Project Configuration.
Disable then re-enable dependency management (right-click Maven->Disable Dependency Management then Maven->Enable Dependency Management
Close the project and reopen it.
...
How do I remove the horizontal scrollbar in a div?
...
To hide the horizontal scrollbar, we can just select the scrollbar of the required div and set it to display: none;
One thing to note is that this will only work for WebKit-based browsers (like Chrome) as there is no such option available for Mozilla.
In order to selec...
闲扯Nginx的accept_mutex配置 - 更多技术 - 清泛网 - 专注C/C++及内核技术
...相关的解释：
OS may wake all processes waiting on accept() and select(), this is called thundering herd problem. This is a problem if you have a lot of workers as in Apache (hundreds and more), but this insensible if you have just several workers as nginx usually has. Therefore turning acc...
Difference between map and collect in Ruby?
..., in C# (3.0)'s LINQ library, it is provided as an extension method called Select. Map is also a frequently used operation in high level languages such as Perl, Python and Ruby; the operation is called map in all three of these languages. A collect alias for map is also provided in Ruby (from Smallt...
How can I extract embedded fonts from a PDF as valid font files?
...or FontForge:
Use the "Open Font" dialogbox used when opening files.
Then select "Extract from PDF" in the filter section of dialog.
Select the PDF file with the font to be extracted.
A "Pick a font" dialogbox opens -- select here which font to open.
Check the FontForge manual. You may need to fol...
How to set java_home on Windows 7?
... installation path:
Right-click the My Computer icon on your desktop and select Properties.
Click the Advanced tab, then click the Environment Variables button.
Under System Variables, click New.
Enter the variable name as JAVA_HOME.
Enter the variable value as the installation path for the Java ...
Android: Test Push Notification online (Google Cloud Messaging) [closed]
...supports both Android and iOS. Easy to use simple website pushtry.com 1. Select you .p12 file 2. Enter device token3 3. Select environment Sandbox or production 4. Enter message 5. Send
– Arvind
Aug 22 '16 at 6:11
...
What's the right way to pass form element state to sibling/parent elements?
...ContextContainer = React.createContext(null);
const initialAppState = {
selected: "Nothing"
};
function App() {
// The app has a state variable and update handler
const [appState, updateAppState] = useState(initialAppState);
return (
<div>
<h1>Passing state between c...