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How to catch integer(0)?
...s way of printing a zero length vector (an integer one), so you could test for a being of length 0:
R> length(a)
[1] 0
It might be worth rethinking the strategy you are using to identify which elements you want, but without further specific details it is difficult to suggest an alternative str...
Is it possible to set a number to NaN or infinity?
...
That will teach me not to jump in with a quip before reading the question over a second time!! Sorry! That said, it wouldn't hurt to say so all the same because it's an easy trap to fall into, NaN != NaN
– David Heffernan
Mar 25 '11 ...
How can I change the color of a Google Maps marker?
.../developers.google.com/maps/documentation/javascript/markers#simple_icons
For v2 maps:
http://code.google.com/apis/maps/documentation/overlays.html#Icons_overview
You would have one set of logic do all the 'regular' pins, and another that does the 'special' pin(s) using the new marker defined.
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In-Place Radix Sort
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Well, here's a simple implementation of an MSD radix sort for DNA. It's written in D because that's the language that I use most and therefore am least likely to make silly mistakes in, but it could easily be translated to some other language. It's in-place but requires 2 * seq.le...
Vagrant reverse port forwarding?
...y=yes -i ~/.vagrant.d/insecure_private_key vagrant@127.0.0.1
SSH supports forwarding ports in the direction you want with the -R guestport:host:hostport option. So, if you wanted to connect to port 12345 on the guest and have it forwarded to localhost:80, you would use this command:
ssh -p 2222 -R...
Integer division with remainder in JavaScript?
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For some number y and some divisor x compute the quotient (quotient) and remainder (remainder) as:
var quotient = Math.floor(y/x);
var remainder = y % x;
...
How to sort a file, based on its numerical values for a field?
...
Take a peek at the man page for sort...
-n, --numeric-sort
compare according to string numerical value
So here is an example...
sort -n filename
share
...
Float vs Decimal in ActiveRecord
...erecord data types confuse me. Err, often. One of my eternal questions is, for a given case,
3 Answers
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Warning: Null value is eliminated by an aggregate or other SET operation in Aqua Data Studio
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You would mostly be using COUNT to summarize over a UID. Therefore
COUNT([uid]) will produce the warning:
Warning: Null value is eliminated by an aggregate or other SET operation.
whilst being used with a left join, where the counted object does not exist.
Using COUNT(*) in this...
Query for array elements inside JSON type
...nction json_array_elements() in a lateral join in the FROM clause and test for its elements:
WITH reports(data) AS (
VALUES ('{"objects":[{"src":"foo.png"}, {"src":"bar.png"}]
, "background":"background.png"}'::json)
)
SELECT *
FROM reports r, json_array_elements(r.data#>'{obj...