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Best way of returning a random boolean value
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A declarative snippet using Array#sample:
random_boolean = [true, false].sample
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Can PostgreSQL index array columns?
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Yes you can index an array, but you have to use the array operators and the GIN-index type.
Example:
CREATE TABLE "Test"("Column1" int[]);
INSERT INTO "Test" VALUES ('{10, 15, 20}');
INSERT INTO "Test" VALUES ('{10, 20, 30}');
CREATE INDEX idx_test on "Test" USING GIN ("Col...
Relatively position an element without it taking up space in document flow
How can I relatively position an element, and have it not take up space in the document flow?
6 Answers
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Dashed line border around UIView
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You can set the border with this pattern using Layer and Bezier path like below examples.
Objective-C
CAShapeLayer *yourViewBorder = [CAShapeLayer layer];
yourViewBorder.strokeColor = [UIColor blackColor].CGColor;
yourViewBorder.fillColor = nil;
yourViewBorder.lineDashPattern...
Shading a kernel density plot between two points.
...ently use kernel density plots to illustrate distributions. These are easy and fast to create in R like so:
5 Answers
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Add support library to Android Studio project
I just installed the new Android Studio and I'm looking for a way to import the support library for Android.
6 Answers
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Selecting data frame rows based on partial string match in a column
...a data.table (but also remember that subsetting approaches for data.frames and data.tables are not identical):
library(data.table)
mtcars[rownames(mtcars) %like% "Merc", ]
iris[iris$Species %like% "osa", ]
If that is what you had, then perhaps you had just mixed up row and column positions for su...
Bash if [ false ] ; returns true
Been learning bash this week and ran into a snag.
6 Answers
6
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How to format a float in javascript?
.....or just use toFixed, as proposed by Tim Büthe. Forgot that one, thanks (and an upvote) for reminder :)
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What is the performance cost of having a virtual method in a C++ class?
...any of its parent classes) means that the class will have a virtual table, and every instance will have a virtual pointer.
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