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How to select the row with the maximum value in each group
...t
# 1: 1 5 2
# 2: 2 17 2
# 3: 3 5 2
In this case, it doesn't make a difference, as there aren't multiple maximum values within any group in your data.
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Identify user in a Bash script called by sudo
...root' then get $SUDO_USER.
Instead of the command whoami use who am i. This runs the who command filtered for the current session. It gives you more info than you need. So, do this to get just the user:
who am i | awk '{print $1}'
Alternatively (and simpler) you can use logname. It does the...
Update a table using JOIN in SQL Server?
... needed to join on the CommonField and also filter on it afterward. Try this:
UPDATE t1
SET t1.CalculatedColumn = t2.[Calculated Column]
FROM dbo.Table1 AS t1
INNER JOIN dbo.Table2 AS t2
ON t1.CommonField = t2.[Common Field]
WHERE t1.BatchNo = '110';
If you're doing something really si...
How to split data into training/testing sets using sample function
...e a look at the createDataPartition function in the caTools package.
Here is a simple example:
data(mtcars)
## 75% of the sample size
smp_size <- floor(0.75 * nrow(mtcars))
## set the seed to make your partition reproducible
set.seed(123)
train_ind <- sample(seq_len(nrow(mtcars)), size = s...
Good scalaz introduction [closed]
... with the fundamentals, I would recommend you to read through http://apocalisp.wordpress.com/ (blog driven by Runar Oli and Mark Harrah) and the weblog of Tony Morris
UPD: "Functors, Applicative Functors and Monoids" chapter of "Learn You a Haskell for Great Good!" has a lot of examples in Haskell ...
Asynchronous shell commands
... use a shell script to start a command. I don't care if/when/how/why it finishes. I want the process to start and run, but I want to be able to get back to my shell immediately...
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How to use __doPostBack()
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You can try this in your web form with a button called btnSave for example:
<input type="button" id="btnSave" onclick="javascript:SaveWithParameter('Hello Michael')" value="click me"/>
<script type="text/javascript">
function...
How to use PyCharm to debug Scrapy projects
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The scrapy command is a python script which means you can start it from inside PyCharm.
When you examine the scrapy binary (which scrapy) you will notice that this is actually a python script:
#!/usr/bin/python
from scrapy.cmdline import exe...
Is there a Java standard “both null or equal” static method?
To save some typing and clarify my code, is there a standard version of the following method?
3 Answers
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Case insensitive XPath contains() possible?
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This is for XPath 1.0. If your environment supports XPath 2.0, see here.
Yes. Possible, but not beautiful.
/html/body//text()[
contains(
translate(., 'ABCDEFGHIJKLMNOPQRSTUVWXYZ', 'abcdefghijklmnopqrstuvwxyz'),
't...