Getting the floor value of a number in SQLite?
You can just use cast it to an integer. It will truncate it, which is equivalent to floor.
floor
Ruby .ceil and .floor
Everything is returned correctly. puts 8/3.ceil == 2 #=> true, because 8/3 returns an Integer, 2 puts 8/3.floor == 2 #=> true, because 8/3 returns an Integer, 2 puts 2.67.ceil == 2 #=> false, because 2.67.ceil is 3 puts 2.67.floor == 2 #=> true, because 2.67.floor is 2 To make things of more sense here, … Read more
How do I create a new Joda DateTime truncated to the last hour? [duplicate]
Wohoo, found it. Simple like everything in Joda once I traced down the calls. DateTime dt = new DateTime().hourOfDay().roundFloorCopy();
Efficient integer floor function in C++
Casting to int is notoriously slow. Maybe you’ve been living under a rock since x86-64, or otherwise missed that this hasn’t been true for a while on x86. 🙂 SSE/SSE2 have an instruction to convert with truncation (instead of the default rounding mode). The ISA supports this operation efficiently precisely because conversion with C semantics … Read more
Rounding to nearest fraction (half, quarter, etc.)
Since you’re looking for fourths (.00, .25, .50, .75), multiply your number by 4, round to nearest whole number as desired (floor if down, ceil if up), then divide by 4. 1.32, down to nearest fourth: 1.32 * 4 = 5.28 floor(5.28) = 5.00 5.00 / 4 = 1.25 Same principle applies for any other … Read more
Taking the floor of a float
As long as your numbers are positive, you can simply convert to an int to round down to the next integer: >>> int(3.1415) 3 For negative integers, this will round up, though.
Does casting to an int after std::floor guarantee the right result?
The range of double is way greater than the range of 32 or 64 bit integers, which is why std::floor returns a double. Casting to int should be fine so long as it’s within the appropriate range – but be aware that a double can’t represent all 64 bit integers exactly, so you may also … Read more
Round minute down to nearest quarter hour
$seconds = time(); $rounded_seconds = round($seconds / (15 * 60)) * (15 * 60); echo “Original: ” . date(‘H:i’, $seconds) . “\n”; echo “Rounded: ” . date(‘H:i’, $rounded_seconds) . “\n”; This example gets the current time and rounds it to the nearest quarter and prints both the original and the rounded time. PS: If you … Read more
Why do lots of (old) programs use floor(0.5 + input) instead of round(input)?
std::round is introduced in C++11. Before that, only std::floor was available so programmers were using it.
Floor or ceiling of a pandas series in python?
You can use NumPy’s built in methods to do this: np.ceil(series) or np.floor(series). Both return a Series object (not an array) so the index information is preserved.