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General suggestions for debugging in R
...orite debugging routine:
When an error occurs, the first thing that I usually do is look at the stack trace by calling traceback(): that shows you where the error occurred, which is especially useful if you have several nested functions.
Next I will set options(error=recover); this immediately sw...
How to create id with AUTO_INCREMENT on Oracle?
...NCREMENT by 1),
c2 VARCHAR2(10)
);
Alternatively, Oracle 12 also allows to use a sequence as a default value:
CREATE SEQUENCE dept_seq START WITH 1;
CREATE TABLE departments (
ID NUMBER(10) DEFAULT dept_seq.nextval NOT NULL,
DESCRIPTION VARCHAR2(50) NOT NULL);
ALTER T...
Understanding events and event handlers in C#
I understand the purpose of events, especially within the context of creating user interfaces. I think this is the prototype for creating an event:
...
What is a “symbol” in Julia?
...its own variables. I.e., you need a way to represent – as data – the foo on the left hand side of this:
foo == "foo"
Now we're getting to the heart of the matter: the difference between a symbol and a string is the difference between foo on the left hand side of that comparison and "foo" on...
Swapping column values in MySQL
...test s1, swap_test s2 SET s1.x=s1.y, s1.y=s2.x WHERE s1.id=s2.id;
Essentially, the 1st table is the one getting updated and the 2nd one is used to pull the old data from.
Note that this approach requires a primary key to be present.
This is my test schema:
CREATE TABLE `swap_test` (
`id` int(1...
sed edit file in place
... out if it is possible to edit a file in a single sed command without manually streaming the edited content into a new file and then renaming the new file to the original file name. I tried the -i option but my Solaris system said that -i is an illegal option. Is there a different way?
...
Looping through a hash, or using an array in PowerShell
...
You can also do this without a variable
@{
'foo' = 222
'bar' = 333
'baz' = 444
'qux' = 555
} | % getEnumerator | % {
$_.key
$_.value
}
share
|
improve this ...
How to pipe list of files returned by find command to cat to view all the files
...ipe it to another utility like cat (so that cat displays the contents of all those files) and basically need to grep something from these files.
...
Equivalent of String.format in jQuery
... Doesn't look like there's much to it. The JavaScript version doesn't have all the fancy number formatting stuff, obviously. blog.stevex.net/index.php/string-formatting-in-csharp
– Nosredna
Jun 24 '09 at 15:09
...
Replace one substring for another string in shell script
...ing/Suzi/$secondString}"
# prints 'I love Sara and Marry'
To replace all occurrences, use ${parameter//pattern/string}:
message='The secret code is 12345'
echo "${message//[0-9]/X}"
# prints 'The secret code is XXXXX'
(This is documented in the Bash Reference Manual, §3.5.3 "She...