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How to check if a map contains a key in Go?
...ring) and ok will receive a bool that will be set to true if "foo" was actually present in the map
evaluates ok, which will be true if "foo" was in the map
If "foo" is indeed present in the map, the body of the if statement will be executed and val will be local to that scope.
...
Force R not to use exponential notation (e.g. e+10)?
...
This is a bit of a grey area. You need to recall that R will always invoke a print method, and these print methods listen to some options. Including 'scipen' -- a penalty for scientific display. From help(options):
‘scipen’: integer. A penalty to be applied wh...
When should I use cross apply over inner join?
...r
),
t AS
(
SELECT 1 AS id
UNION ALL
SELECT 2
)
SELECT *
FROM t
JOIN q
ON q.rn <= t.id
runs for almost 30 seconds, while this one:
WITH t AS
(
SELECT 1 AS id
UNION ALL
SELECT 2
...
Reference: What is variable scope, which variables are accessible from where and what are “undefined
... be in the global scope in a.php doesn't necessarily mean they are, it actually depends on which context that code is included/executed in.
What about functions inside functions and classes?
Every new function declaration introduces a new scope, it's that simple.
(anonymous) functions inside func...
What is the equivalent of MATLAB's repmat in NumPy
I would like to execute the equivalent of the following MATLAB code using NumPy: repmat([1; 1], [1 1 1]) . How would I accomplish this?
...
Can I use git diff on untracked files?
...The upshot is that your "untracked" file now becomes a modification to add all the content to this zero-length file, and that shows up in the "git diff" output.
git diff
echo "this is a new file" > new.txt
git diff
git add -N new.txt
git diff
diff --git a/new.txt b/new.txt
index e69de29..3b2ae...
How to calculate a logistic sigmoid function in Python?
...s log1p.
In general, the multinomial logistic sigmoid is:
def nat_to_exp(q):
max_q = max(0.0, np.max(q))
rebased_q = q - max_q
return np.exp(rebased_q - np.logaddexp(-max_q, np.logaddexp.reduce(rebased_q)))
(However, logaddexp.reduce could be more accurate.)
...
What does curly brackets in the `var { … } = …` statements do?
...h JavaScript 1.7 features. The first one is block-level variables:
let allows you to declare variables, limiting its scope to the block, statement, or expression on which it is used. This is unlike the var keyword, which defines a variable globally, or locally to an entire function regardless of...
AngularJS : Initialize service with asynchronous data
...ise;
}
}})
}):
Your controller won't get instantiated before all dependencies are resolved:
app.controller('MainCtrl', function($scope,MyService) {
console.log('Promise is now resolved: '+MyService.doStuff().data)
$scope.data = MyService.doStuff();
});
I've made an example at pl...
Python constructors and __init__
Why are constructors indeed called "Constructors"? What is their purpose and how are they different from methods in a class?
...