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Pass a data.frame column name to a function
...(x[,column])
}
fun1(df, "B", max)
Alternatively, using [[ also works for selecting a single column at a time:
df <- data.frame(A=1:10, B=2:11, C=3:12)
fun1 <- function(x, column){
max(x[[column]])
}
fun1(df, "B")
...
How can I inspect disappearing element in a browser?
...
An alternative method in Chrome:
Open devTools (F12).
Select the "Sources" tab.
While the element you want is displayed, press F8 (or Ctrl+/). This will break script execution and "freeze" the DOM exactly as it is displayed.
From this point, use Ctrl+Shift+C to select the elemen...
Failed to build gem native extension (installing Compass)
...l the Xcode Command Line Tools this is the key to install Compass.
xcode-select --install
Installing the Xcode Command Line Tools are the key to getting Compass working on OS X
3. Install Compass
sudo gem install compass
...
How can I remove an SSH key?
...gether.
Go to System --> Preferences --> Startup Applications, and unselect the "SSH Key Agent (Gnome Keyring SSH Agent)" box -- you'll need to scroll down to find it.
You'll still get an ssh-agent, only now it will behave sanely: no keys autoloaded, you run ssh-add to add them, and if you w...
HTML text input allow only numeric input
...x, inputFilter) {
["input", "keydown", "keyup", "mousedown", "mouseup", "select", "contextmenu", "drop"].forEach(function(event) {
textbox.addEventListener(event, function() {
if (inputFilter(this.value)) {
this.oldValue = this.value;
this.oldSelectionStart = this.selecti...
Using HTML5/Canvas/JavaScript to take in-browser screenshots
Google's "Report a Bug" or "Feedback Tool" lets you select an area of your browser window to create a screenshot that is submitted with your feedback about a bug.
...
Best way to store time (hh:mm) in a database
...t a glance and performing calculations on them are straightforward.
E.g.
SELECT DATEDIFF(MINUTE, event_start, event_end)
ISO8601 date standard
If using SQLite then you don't have this, so instead use a Text field and store it in ISO8601 format eg.
"2013-01-27T12:30:00+0000"
Notes:
This use...
TypeError: got multiple values for argument
...r example, let's imagine a function that draws a colored box. The function selects the color to be used and delegates the drawing of the box to another function, relaying all extra arguments.
def color_box(color, *args, **kwargs):
painter.select_color(color)
painter.draw_box(*args, **kwargs...
Debugging iframes with Chrome developer tools
...ools in Chrome, there is a bar along the top, called the Execution Context Selector (h/t felipe-sabino), just under the Elements, Network, Sources... tabs, that changes depending on the context of the current tab. When in the Console tab there is a dropdown in that bar that allows you to select the...
Stop the 'Ding' when pressing Enter
...ecutes. The only thing that happens is all the Text in the TextBox becomes selected (and I don't even have code that selects any text)
– bendr
Jun 9 '11 at 10:15
1
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