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How to select the row with the maximum value in each group
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Here's a data.table solution:
require(data.table) ## 1.9.2
group <- as.data.table(group)
If you want to keep all the entries corresponding to max values of pt within each group:
group[group[, .I[pt == max(pt)], by=Subject]$V1]
# ...
Combine two data frames by rows (rbind) when they have different sets of columns
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An alternative with data.table:
library(data.table)
df1 = data.frame(a = c(1:5), b = c(6:10))
df2 = data.frame(a = c(11:15), b = c(16:20), c = LETTERS[1:5])
rbindlist(list(df1, df2), fill = TRUE)
rbind will also work in data.table as long as the...
MySQL - Using COUNT(*) in the WHERE clause
...similar to this:
SELECT column_name, aggregate_function(column_name)
FROM table_name
WHERE column_name operator value
GROUP BY column_name
HAVING aggregate_function(column_name) operator value;
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How do I import .sql files into SQLite 3?
...o, your SQL is invalid - you need ; on the end of your statements:
create table server(name varchar(50),ipaddress varchar(15),id init);
create table client(name varchar(50),ipaddress varchar(15),id init);
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Switch statement fallthrough in C#?
...ere one takes a value, computes an offset from it (whether by looking up a table indexed by a perfect hash of the value, or by actual arithmetic on the value*). It's worth noting at this point that today, C# compilation will sometimes turn switch into the equivalent if-else, and sometimes use a hash...
What is the best way to insert source code examples into a Microsoft Word document?
... I initially used the same technique but have since changed to using a table of 1x1 because I found that text boxes are an f'ing pain to position. I tried "top and bottom" so the text would be only before and after, and Word would magically move the box up or down, sometimes the caption would no...
How to display the function, procedure, triggers source code in postgresql?
.... Just know the following way, may be it will help you!
step 1 : Get the table oid of the trigger:
skytf=> select tgrelid from pg_trigger where tgname='insert_tbl_tmp_trigger';
tgrelid
---------
26599
(1 row)
step 2: Get the table name of the above oid !
s...
What are the complexity guarantees of the standard containers?
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I'm not aware of anything like a single table that lets you compare all of them in at one glance (I'm not sure such a table would even be feasible).
Of course the ISO standard document enumerates the complexity requirements in detail, sometimes in various rather r...
How to convert local time string to UTC?
... platform. You could use tzlocal.get_localzone() to provide tzdata in a portable way. (2) fromtimestamp(t, tz) may fail for non-pytz timezones. (3) datetime(*struct_time[:6]) you are missing *. (4) timegm(), utctimetuple(), struct_time -based solutions drop fractions of a second. You could use an e...