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Convert column classes in data.table
...oblem using data.table: How do I convert column classes? Here is a simple example: With data.frame I don't have a problem converting it, with data.table I just don't know how:
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Getting SyntaxError for print with keyword argument end=' '
...ave this python script where I need to run gdal_retile.py ,
but I get an exception on this line:
14 Answers
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How to take the first N items from a generator or list in Python? [duplicate]
...Slicing a list
top5 = array[:5]
To slice a list, there's a simple syntax: array[start:stop:step]
You can omit any parameter. These are all valid: array[start:], array[:stop], array[::step]
Slicing a generator
import itertools
top5 = itertools.islice(my_list, 5) # grab the first five element...
Drawing Isometric game worlds
... technique for mapping the tiles to the screen can be said that the tile's x and y coordinates are on the vertical and horizontal axes.
"Drawing in a diamond" approach:
By drawing an isometric map using "drawing in a diamond", which I believe refers to just rendering the map by using a nested for-...
Bitwise operation and usage
...wise it's 0.
OR is 1 if one or both of its inputs are 1, otherwise it's 0.
XOR is 1 only if exactly one of its inputs are 1, otherwise it's 0.
NOT is 1 only if its input is 0, otherwise it's 0.
These can often be best shown as truth tables. Input possibilities are on the top and left, the resulta...
How can I handle R CMD check “no visible binding for global variable” notes when my ggplot2 syntax i
...instead of aes? This should work, although I haven't tried it:
aes_string(x = 'x.values', y = 'y.values')
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Does it make sense to use “as” instead of a cast even if there is no null check? [closed]
In development blogs, online code examples and (recently) even a book, I keep stumbling about code like this:
13 Answers
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How do I draw a grid onto a plot in Python?
...ot using pylab in Python and now I would like to superimpose a grid of 10x10 onto the scatter plot. How do I do that?
5 A...
Convert nullable bool? to bool
...will represent. If null should be false, you can do this:
bool newBool = x.HasValue ? x.Value : false;
Or:
bool newBool = x.HasValue && x.Value;
Or:
bool newBool = x ?? false;
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Why doesn't c++ have &&= or ||= for booleans?
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The reason is that b & 2 performs integer promotion such that the expression is then equivalent to static_cast<int>(b) & 2, which results in 0, which is then converted back into a bool. So it’s true that the existence of an operator &&= would improve type safety.
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