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Pan & Zoom Image
....RenderTransform;
double zoom = e.Delta > 0 ? .2 : -.2;
st.ScaleX += zoom;
st.ScaleY += zoom;
}
To handle the panning the first thing I did was to handle the MouseLeftButtonDown event on the image, to capture the mouse and to record it's location, I also store the current value of t...
How to concatenate twice with the C preprocessor and expand a macro as in “arg ## _ ## MACRO”?
...
Standard C Preprocessor
$ cat xx.c
#define VARIABLE 3
#define PASTER(x,y) x ## _ ## y
#define EVALUATOR(x,y) PASTER(x,y)
#define NAME(fun) EVALUATOR(fun, VARIABLE)
extern void NAME(mine)(char *x);
$ gcc -E xx.c
# 1 "xx.c"
# 1 "<built-in>"
# 1 "<...
Unable to load DLL 'SQLite.Interop.dll'
Periodically I am getting the following exception:
41 Answers
41
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Alternate output format for psql
...t needed to spend more time staring at the documentation. This command:
\x on
will do exactly what I wanted. Here is some sample output:
select * from dda where u_id=24 and dda_is_deleted='f';
-[ RECORD 1 ]------+---------------------------------------------------------------------------------...
Checking for empty arrays: count vs empty
...s simply that something that should have happened, didn't happen: the non-existence of the member variable in the subclass was treated exactly the same way as though this member variable, an array, was empty — i.e., as though it had no elements). This is problematic, and another example of PHP bei...
What's the fastest way to merge/join data.frames in R?
For example (not sure if most representative example though):
5 Answers
5
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How do you match only valid roman numerals with a regular expression?
...hinking about my other problem , i decided I can't even create a regular expression that will match roman numerals (let alone a context-free grammar that will generate them)
...
How to convert strings into integers in Python?
...ins lists, only one level), you could do this in Python 2:
T2 = [map(int, x) for x in T1]
In Python 3:
T2 = [list(map(int, x)) for x in T1]
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“var” or no “var” in JavaScript's “for-in” loop?
...s I show here. First, there is this approach where the iteration variable x is explicitly declared:
9 Answers
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How to convert a factor to integer\numeric without loss of information?
...nd may
happen by implicit coercion. To
transform a factor f to
approximately its original numeric
values, as.numeric(levels(f))[f] is
recommended and slightly more
efficient than
as.numeric(as.character(f)).
The FAQ on R has similar advice.
Why is as.numeric(levels(f))[f] more ef...