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Create an empty data.frame
... stringsAsFactors=FALSE)
str(df)
> str(df)
'data.frame': 0 obs. of 5 variables:
$ Doubles : num
$ Ints : int
$ Factors : Factor w/ 0 levels:
$ Logicals : logi
$ Characters: chr
N.B. :
Initializing a data.frame with an empty column of the wrong type does not ...
TypeScript: problems with type system
I'm just testing typescript in VisualStudio 2012 and have a problem with its type system. My html site has a canvas tag with the id "mycanvas". I'm trying to draw a rectangle on this canvas. Here's the code
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How to declare a global variable in a .js file
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edited Sep 6 '09 at 15:10
answered Jun 3 '09 at 11:48
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WiX tricks and tips
...DIR)\Config.wxi?>
<Product ... >
<Package InstallerVersion="200" InstallPrivileges="elevated"
InstallScope="perMachine" Platform="$(var.Platform)"
Compressed="yes" Description="$(var.ProductName)" />
and
<Directory Id="TARGETDIR" Name="SourceDir">
&l...
How to make join queries using Sequelize on Node.js
... pkyeck
15.9k1414 gold badges6868 silver badges103103 bronze badges
answered Dec 9 '13 at 9:28
Jan Aagaard MeierJan Aagaard Meier
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jQuery get the location of an element relative to window
... log(eTop - $(window).scrollTop());
});
});
#element {
margin: 140px;
text-align: center;
padding: 5px;
width: 200px;
height: 200px;
border: 1px solid #0099f9;
border-radius: 3px;
background: #444;
color: #0099d9;
opacity: 0.6;
}
#log {
position: fixed;
t...
MySQL select 10 random rows from 600K rows fast
How can I best write a query that selects 10 rows randomly from a total of 600k?
26 Answers
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Check if inputs are empty using jQuery
...g');
}
});
And you don't necessarily need .length or see if it's >0 since an empty string evaluates to false anyway but if you'd like to for readability purposes:
$('#apply-form input').blur(function()
{
if( $(this).val().length === 0 ) {
$(this).parents('p').addClass('warning'...
What should I do if the current ASP.NET session is null?
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edited Jun 20 at 9:12
Community♦
111 silver badge
answered Sep 5 '09 at 8:51
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