Tag: math

58 votes
12 answers
923 views
Why doesn't GCC optimize a*a*a*a*a*a to (a*a*a)*(a*a*a)?

I am doing some numerical optimization on a scientific application. One thing I noticed is that GCC will optim

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Venice
0 1 0 9
asked 07 September, 2021
60 votes
5 answers
472 views
How do I calculate a point on a circle’s circumference?

How can the following function be implemented in various languages? Calculate the (x,y) point on the circumfe

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Joseph
0 1 0 9
asked 07 September, 2021
57 votes
1 answers
2.8K views
Rounding BigDecimal to *always* have two decimal places

I'm trying to round BigDecimal values up, to two decimal places. I'm using BigDecimal rounded = va

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Rufus
0 1 0 9
asked 07 September, 2021
52 votes
3 answers
1.1K views
Why does Python's hash of infinity have the digits of π?

The hash of infinity in Python has digits matching pi: >>> inf = float('inf') >>>

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Xavier
0 1 0 9
asked 07 September, 2021
53 votes
9 answers
2.8K views
Is log(n!) = Θ(n·log(n))?

I am to show that log(n!) = Θ(n·log(n)). A hint was given that I should show the upper bound with nn and sh

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Santiago
0 1 0 9
asked 07 September, 2021
60 votes
11 answers
2.4K views
How can I round down a number in Javascript?

How can I round down a number in JavaScript? math.round() doesn't work because it rounds it to the neare

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Rufus
0 1 0 9
asked 07 September, 2021
58 votes
10 answers
2.7K views
How can I ensure that a division of integers is always rounded up?

I want to ensure that a division of integers is always rounded up if necessary. Is there a better way than thi

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Robt
0 1 0 9
asked 07 September, 2021
63 votes
6 answers
1.9K views
What is the behavior of integer division?

For example, int result; result = 125/100; or result = 43/100; Will result always be the floor of the

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Hallie
0 1 0 9
asked 07 September, 2021
62 votes
8 answers
1.5K views
How to scale down a range of numbers with a known min and max value

So I am trying to figure out how to take a range of numbers and scale the values down to fit a range. The rea

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Keila
0 1 0 9
asked 07 September, 2021
58 votes
11 answers
502 views
Safest way to convert float to integer in python?

Python's math module contain handy functions like floor & ceil. These functions take a floating point

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Karolyn
0 1 0 9
asked 07 September, 2021
57 votes
21 answers
596 views
Generate a random point within a circle (uniformly)

I need to generate a uniformly random point within a circle of radius R. I realize that by just picking a uni

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Wilber
0 1 0 9
asked 07 September, 2021
48 votes
19 answers
452 views
Mapping two integers to one, in a unique and deterministic way

Imagine two positive integers A and B. I want to combine these two into a single integer C. There can be no

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Benton
0 1 0 9
asked 07 September, 2021
66 votes
26 answers
2.8K views
Too many 'if' statements?

The following code does work how I need it to, but it's ugly, excessive or a number of other things. I&ap

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Stacia
0 1 0 9
asked 07 September, 2021
63 votes
22 answers
1.1K views
How does C compute sin() and other math functions?

I've been poring through .NET disassemblies and the GCC source code, but can't seem to find anywhere

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Thurman
0 1 0 9
asked 07 September, 2021
56 votes
19 answers
644 views
The most efficient way to implement an integer based power function pow(int, int)

What is the most efficient way given to raise an integer to the power of another integer in C? // 2^3 pow(2,3

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Stacia
0 1 0 9
asked 07 September, 2021
61 votes
13 answers
1.1K views
Calculating arithmetic mean (one type of average) in Python

Is there a built-in or standard library method in Python to calculate the arithmetic mean (one type of average

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Juliane
0 1 0 9
asked 07 September, 2021
62 votes
7 answers
937 views
Why is division in Ruby returning an integer instead of decimal value?

For example: 9 / 5 #=> 1 but I expected 1.8. How can I get the correct decimal (non-integer) result? Wh

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Robt
0 1 0 9
asked 07 September, 2021
53 votes
23 answers
2K views
How to determine if a list of polygon points are in clockwise order?

Having a list of points, how do I find if they are in clockwise order? For example: point[0] = (5,0) point[1

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Charis
0 1 0 9
asked 07 September, 2021
63 votes
21 answers
2.4K views
Why can't decimal numbers be represented exactly in binary?

There have been several questions posted to SO about floating-point representation. For example, the decimal n

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Renaldo
0 1 0 9
asked 07 September, 2021
57 votes
11 answers
905 views
JavaScript % (modulo) gives a negative result for negative numbers

According to Google Calculator (-13) % 64 is 51. According to Javascript (see this JSBin) it is -13. How do

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Percy
0 1 0 9
asked 07 September, 2021