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Pass a data.frame column name to a function
... just use the column name directly:
df <- data.frame(A=1:10, B=2:11, C=3:12)
fun1 <- function(x, column){
max(x[,column])
}
fun1(df, "B")
fun1(df, c("B","A"))
There's no need to use substitute, eval, etc.
You can even pass the desired function as a parameter:
fun1 <- function(x, colu...
How to select rows from a DataFrame based on column values?
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4135
To select rows whose column value equals a scalar, some_value, use ==:
df.loc[df['column_name'...
Programmatically obtain the Android API level of a device?
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Vivek
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answered Nov 2 '14 at 11:01
Arkadiusz Cieślińsk...
How to change the CHARACTER SET (and COLLATION) throughout a database?
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371
change database collation:
ALTER DATABASE <database_name> CHARACTER SET utf8 COLLATE utf...
What's the difference between --general-numeric-sort and --numeric-sort options in gnu sort
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3 Answers
3
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Aggregate / summarize multiple variables per group (e.g. sum, mean)
...~ variable, sum)
# year month x1 x2
1 2000 1 -80.83405 -224.9540159
2 2000 2 -223.76331 -288.2418017
3 2000 3 -188.83930 -481.5601913
4 2000 4 -197.47797 -473.7137420
5 2000 5 -259.07928 -372.4563522
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Should I use encoding declaration in Python 3?
Python 3 uses UTF-8 encoding for source-code files by default. Should I still use the encoding declaration at the beginning of every source file? Like # -*- coding: utf-8 -*-
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Backporting Python 3 open(encoding=“utf-8”) to Python 2
I have a Python codebase, built for Python 3, which uses Python 3 style open() with encoding parameter:
6 Answers
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Rank function in MySQL
...INSERT INTO person VALUES (2, 'Jane', 20, 'F');
INSERT INTO person VALUES (3, 'Jack', 30, 'M');
INSERT INTO person VALUES (4, 'Bill', 32, 'M');
INSERT INTO person VALUES (5, 'Nick', 22, 'M');
INSERT INTO person VALUES (6, 'Kathy', 18, 'F');
INSERT INTO person VALUES (7, 'Steve', 36, 'M');
INSERT INT...