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How to use the 'sweep' function
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sweep() is typically used when you operate a matrix by row or by column, and the other input of the operation is a different value for each row / column. Whether you operate by row or column is defined by MARGIN, as for apply(). The values used for what I called "the other input" is defined by STA...
dplyr summarise: Equivalent of “.drop=FALSE” to keep groups with zero length in output
...ies, levels=c(levels(iris$Species), "empty_level"))
# Species is a factor and empty groups are included in the output
iris %>% group_by(Species, .drop=FALSE) %>% tally
#> Species n
#> 1 setosa 50
#> 2 versicolor 50
#> 3 virginica 50
#> 4 empty_level ...
Check if a Postgres JSON array contains a string
...ovements on a table of 1,000,000 rabbits where each rabbit likes two foods and 10% of them like carrots:
d=# -- Postgres 9.3 solution
d=# explain analyze select info->>'name' from rabbits where exists (
d(# select 1 from json_array_elements(info->'food') as food
d(# where food::text = '"...
Embedding SVG into ReactJS
... any namespaced (colon-separated) attribute, e.g. xlink:href, remove the : and capitalize the second part of the attribute, e.g. xlinkHref. Here’s an example of an svg with <defs>, <use>, and inline styles:
function SvgWithXlink (props) {
return (
<svg
width...
Using python map and other functional tools
This is quite n00bish, but I'm trying to learn/understand functional programming in python. The following code:
9 Answers
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Converting a column within pandas dataframe from int to string
I have a dataframe in pandas with mixed int and str data columns. I want to concatenate first the columns within the dataframe. To do that I have to convert an int column to str .
I've tried to do as follows:
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Why am I getting an Exception with the message “Invalid setup on a non-virtual (overridable in VB) m
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Moq cannot mock non-virtual methods and sealed classes. While running a test using mock object, MOQ actually creates an in-memory proxy type which inherits from your "XmlCupboardAccess" and overrides the behaviors that you have set up in the "SetUp" method. And...
JavaScript OOP in NodeJS: how?
...e below is impossible)
//you should do
//method.$getAge = _super.getAge;
//and then use this.$getAge() instead of super()
method.getAge = function() {
return _super.getAge.call(this);
};
module.exports = Mouse;
Also you can consider "Method borrowing" instead of vertical inheritance. You don'...
How to declare constant map
...a func you can declare it like:
romanNumeralDict := map[int]string{
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And in Go there is no such thing as a constant map. More information can be found here.
Try it out on the Go playground.
share
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What is the meaning of the CascadeType.ALL for a @ManyToOne JPA association
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+1 for the best and shortest explanation of mappedBy I've ever come across.
– Ridcully
Sep 30 '14 at 6:19
4
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