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How does grep run so fast?
...looks first
for the final letter of the target string, and uses a lookup table to
tell it how far ahead it can skip in the input whenever it finds a
non-matching character.
GNU grep also unrolls the inner loop of Boyer-Moore, and sets up the
Boyer-Moore delta table entries in such a way...
Extract a dplyr tbl column as a vector
...yr tbl as a vector, from a tbl with database back-end (i.e. the data frame/table can't be subset directly)?
7 Answers
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Order discrete x scale by frequency/value
...
ggplot(mtcars, aes(factor(cyl))) + geom_bar()
# Manual levels
cyl_table <- table(mtcars$cyl)
cyl_levels <- names(cyl_table)[order(cyl_table)]
mtcars$cyl2 <- factor(mtcars$cyl, levels = cyl_levels)
# Just to be clear, the above line is no different than:
# mtcars$cyl2 <- factor(m...
How can I reorder my divs using only CSS?
...ution uses only CSS and works with variable content
#wrapper { display: table; }
#firstDiv { display: table-footer-group; }
#secondDiv { display: table-header-group; }
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Selecting data frame rows based on partial string match in a column
...rent approach. I don't know if that's a reference to the %like% from "data.table", but if it is, you can definitely use it as follows.
Note that the object does not have to be a data.table (but also remember that subsetting approaches for data.frames and data.tables are not identical):
library(dat...
TSQL - Cast string to integer or return default value
...> 2147483647 RETURN NULL
RETURN @I
END
GO
-- Testing
DECLARE @Test TABLE(Value nvarchar(50)) -- Result
INSERT INTO @Test SELECT '1234' -- 1234
INSERT INTO @Test SELECT '1,234' -- 1234
INSERT INTO @Test SELECT '1234.0' -- 1234
INSERT INTO @Test SELECT '-1234' ...
Are there constants in JavaScript?
...nly enjoys a smattering of browser support: http://kangax.github.io/compat-table/es6/. The syntax is:
const CONSTANT_NAME = 0;
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How to export and import a .sql file from command line with options? [duplicate]
...an we set constraints like enable/disable foreign key check or export only table structure with mysqldump
– AZinkey
Feb 28 '15 at 2:48
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Tools for Generating Mock Data? [closed]
...t looks close to your requirements.
it can generate data for an existing table definition (or even anonymize production data)
it can generate larges data set (unlimited size)
it supports various input (CSV, Flat Files, DBUnit) and output format (CSV, Flat Files, DBUnit, XML, Excel, Scripts)
it can...
How to use count and group by at the same select statement
...atement.
Is there a way for this directly from sql?
For example, having a table with users I want to select the different towns and the total number of users
...