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Summarizing multiple columns with dplyr? [duplicate]
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Need test on the large dataset.
– Artem Klevtsov
Mar 1 '16 at 19:21
1
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Make Div overlay ENTIRE page (not just viewport)?
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@Arve It gets you close, but it's better to use a time-tested reset sheet instead. Check out meyerweb.com/eric/tools/css/reset for more information - you'll love it, I assure you :)
– Sampson
May 17 '10 at 20:06
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How to rename items in values() in Django?
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Without using any other manager method (tested on v3.0.4):
from django.db.models import F
MyModel.objects.values(renamed_value=F('cryptic_value_name'))
Excerpt from Django docs:
An F() object represents the value of a model field or annotated
column. It m...
Difference between os.getenv and os.environ.get
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Which version of Python have you tested with. On 3.7.2, os.getenv is just a wrapper for os.environ.get, so I am getting very minimal overhead.
– Preslav Rachev
Jan 7 '19 at 15:19
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What is the difference between required and ng-required?
...g-required allows you to set the required attribute depending on a boolean test (for instance, only require field B - say, a student number - if the field A has a certain value - if you selected "student" as a choice)
As an example, <input required> and <input ng-required="true"> are es...
iOS: Compare two dates
...bellow lines of code in viewDidload or according to your scenario.
-(void)testDateComaparFunc{
NSString *getTokon_Time1 = @"2016-05-31 03:19:05 +0000";
NSString *getTokon_Time2 = @"2016-05-31 03:18:05 +0000";
NSDateFormatter *dateFormatter=[NSDateFormatter new];
[dateFormatter setDateFormat:@"yyyy...
Comparing two java.util.Dates to see if they are in the same day
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This is by way the fastest solution -- thanks a lot, exactly what I was looking for; as I have to check a lot of dates ...
– Ridcully
May 11 '12 at 19:20
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How do SQL EXISTS statements work?
... SELECT DISTINCT ... FROM SUPPLIERS JOIN ORDERS ... on SQL Server, haven't tested on Oracle or MySQL lately.
– OMG Ponies
May 1 '11 at 16:40
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Convert a float64 to an int in Go
...intf and strconv.Atois() were 2 orders of magnitude slower according to my tests with a matrix of float64 values that were intended to become correctly rounded int values.
package main
import (
"fmt"
"math"
)
func main() {
var x float64 = 5.51
var y float64 = 5.50
var z float64 ...
iOS 7 TextKit - How to insert images inline with text?
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@AndyHin I haven't tested this myself but one option is possibly to render your UIView to a UIImage and then add it as an NSTextAttachment. In order to render the view to an image check out this question: http://stackoverflow.com/questions/4334...