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javascript set a variable if undefined
...f the variable is strictly undefined then the safest way is to write:
var x = (typeof x === 'undefined') ? your_default_value : x;
On newer browsers it's actually safe to write:
var x = (x === undefined) ? your_default_value : x;
but be aware that it is possible to subvert this on older browse...
How to avoid warning when introducing NAs by coercion
...
Use suppressWarnings():
suppressWarnings(as.numeric(c("1", "2", "X")))
[1] 1 2 NA
This suppresses warnings.
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Convert Int to String in Swift
...
Converting Int to String:
let x : Int = 42
var myString = String(x)
And the other way around - converting String to Int:
let myString : String = "42"
let x: Int? = myString.toInt()
if (x != nil) {
// Successfully converted String to Int
}
Or if ...
pyplot axes labels for subplots
...hen set the common labels.
import random
import matplotlib.pyplot as plt
x = range(1, 101)
y1 = [random.randint(1, 100) for _ in xrange(len(x))]
y2 = [random.randint(1, 100) for _ in xrange(len(x))]
fig = plt.figure()
ax = fig.add_subplot(111) # The big subplot
ax1 = fig.add_subplot(211)
ax2 =...
Tricks to manage the available memory in an R session
...em. But by far the most effective solution was ... to run under 64-bit Linux with ample memory.
27 Answers
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In php, is 0 treated as empty?
Code will explain more:
18 Answers
18
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Drop data frame columns by name
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You can use a simple list of names :
DF <- data.frame(
x=1:10,
y=10:1,
z=rep(5,10),
a=11:20
)
drops <- c("x","z")
DF[ , !(names(DF) %in% drops)]
Or, alternatively, you can make a list of those to keep and refer to them by name :
keeps <- c("y", "a")
DF[keeps]
EDI...
Entity Framework - Include Multiple Levels of Properties
... well for Lists on objects. But what if I need to go two levels deep? For example, the method below will return ApplicationServers with the included properties shown here. However, ApplicationsWithOverrideGroup is another container that holds other complex objects. Can I do an Include() on that prop...
How do I check if an integer is even or odd? [closed]
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