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Mean per group in a data.frame [duplicate]
... Group.1 Rate1 Rate2
1 Aira 16.33333 47.00000
2 Ben 31.33333 50.33333
3 Cat 44.66667 54.00000
Here we aggregate columns 3 and 4 of data.frame d, grouping by d$Name, and applying the mean function.
Or, using a formula interface:
aggregate(. ~ Name, d[-2], mean)
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Max size of an iOS application
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350
4GB's is the maximum size your iOS app can be.
As of January 26, 2017
App Size for iOS (& ...
How to “fadeOut” & “remove” a div in jQuery?
...aolo BergantinoPaolo Bergantino
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How to draw polygons on an HTML5 canvas?
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ctx.fillStyle = '#f00';
ctx.beginPath();
ctx.moveTo(0, 0);
ctx.lineTo(100,50);
ctx.lineTo(50, 100);
ctx.lineTo(0, 90);
ctx.closePath();
ctx.fill();
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How to get row from R data.frame
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Matt ParkerMatt Parker
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How do you divide each element in a list by an int?
...e idiomatic way would be to use list comprehension:
myList = [10,20,30,40,50,60,70,80,90]
myInt = 10
newList = [x / myInt for x in myList]
or, if you need to maintain the reference to the original list:
myList[:] = [x / myInt for x in myList]
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Make a UIButton programmatically in Swift
...stLabel.numberOfLines = 5
myFirstLabel.frame = CGRectMake(15, 54, 300, 500)
myFirstButton.setTitle("✸", forState: .Normal)
myFirstButton.setTitleColor(UIColor.blueColor(), forState: .Normal)
myFirstButton.frame = CGRectMake(15, -50, 300, 500)
myFirstButton.addTarget(self, actio...
How expensive is the lock statement?
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Here is an article that goes into the cost. Short answer is 50ns.
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Delete rows from a pandas DataFrame based on a conditional expression involving len(string) giving K
...tion>].index)
Example
To remove all rows where column 'score' is < 50:
df = df.drop(df[df.score < 50].index)
In place version (as pointed out in comments)
df.drop(df[df.score < 50].index, inplace=True)
Multiple conditions
(see Boolean Indexing)
The operators are: | for or, &am...
Change Canvas.Left property in code behind?
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Canvas.SetLeft(theObject, 50)
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