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Does Java read integers in little endian or big endian?
...mats that use some form of Huffman encoding (i.e. all of them). For extra fun, JPEG is "bitwise big-endian" (i.e. the most significant bit is the "first" bit) and LZ is "bitwise little-endian". I once worked on a proprietary compression format that used both formats under the hood. Oh, that was f...
Remove duplicated rows using dplyr
...ction for this purpose.
Original answer below:
library(dplyr)
set.seed(123)
df <- data.frame(
x = sample(0:1, 10, replace = T),
y = sample(0:1, 10, replace = T),
z = 1:10
)
One approach would be to group, and then only keep the first row:
df %>% group_by(x, y) %>% filter(row_nu...
Checking if a string can be converted to float in Python
... ------------
print(isfloat("")) False
print(isfloat("1234567")) True
print(isfloat("NaN")) True nan is also float
print(isfloat("NaNananana BATMAN")) False
print(isfloat("123.456")) True
print(isfloat("123.E4")) ...
Is there a way to get a collection of all the Models in your Rails app?
...ase. Don't know how you can list all the classes though...
EDIT: Just for fun, I found a way to list all classes
Module.constants.select { |c| (eval c).is_a? Class }
EDIT: Finally succeeded in listing all models without looking at directories
Module.constants.select do |constant_name|
constan...
【转】用App Inventor 2实现电子围栏功能 - App应用开发 - 清泛IT社区，为创新赋能！
...示动图
侵删，文章来源：https://makelog.dfrobot.com.cn/user-1229.html
Alternate output format for psql
... using PostgreSQL 8.4 on Ubuntu. I have a table with columns c1 through cN . The columns are wide enough that selecting all columns causes a row of query results to wrap multiple times. Consequently, the output is hard to read.
...
How can I parse a local JSON file from assets folder into a ListView?
...using below code.
and then you can simply read this string return by this function as
public String loadJSONFromAsset() {
String json = null;
try {
InputStream is = getActivity().getAssets().open("yourfilename.json");
int size = is.available();
byte[] buffer = new b...
How can I view a git log of just one user's commits?
...commits commited (but not necessarily authored) by Adam, replace %an with %cn. More details about this are in my blog post here: http://dymitruk.com/blog/2012/07/18/filtering-by-author-name/
share
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Dynamic SQL - EXEC(@SQL) versus EXEC SP_EXECUTESQL(@SQL)
...
EXEC('SELECT * FROM FOO WHERE ID=?', 123) will replace the parameter placeholder "?" with the value 123 and then execute the query, returning a result for SELECT * FROM FOO WHERE ID=123
– Peter Wone
Jun 1 '10 at 23:27
...
How to search through all Git and Mercurial commits in the repository for a certain string?
...ways to do that. See "hg help revsets", esp the desc(), user(), and file() functions. There are also hg log switches for most of this behavior. In my experience, though -k/keyword() is usually the most helpful way to search for things.
– Kevin Horn
Dec 17 '12...