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# William

##### Last seen: Today
4,777 2012 이후 총 참여 횟수

Semi-retired physicist with interests in numerical modeling and mathematics.

#### William's 배지

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Given an isotope's atomic mass (in amu), half-life (in years(a) or days(d)), and average kinetic energy absorbed (of emitted dec...

약 23시간 전

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Compute a sum involving the totient over divisors of a number
Write a function to compute the following sum: where is the totient function. The sum is computed over the divisors of (inc...

약 23시간 전

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The Piggy Bank Problem
Given a cylindrical piggy bank with radius g and height y, return the bank's volume. [ g is first input argument.] Bonus though...

2일 전

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Compute the effective conductivity of a heterogeneous aquifer
Slow flow through soil or another porous medium follows Darcy’s law, which relates the flow of water to the gradient in piezome...

3일 전

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Nuclear Binding Energy
Compute the approximate nuclear binding energy in MeV using the least-squares fit of the semi-emirical mass formula. Round to th...

3일 전

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Identify Ruth-Aaron numbers
After Hank Aaron hit his 715th home run and passed Babe Ruth’s total of 714, Carl Pomerance noticed that the union of the prime ...

9일 전

답변 있음
Bitshift cannot work on negative numbers
I believe this is happening for the following reason: The documentation states that "If A is a double array, and ASSUMEDTYPE is...

11일 전 | 2

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Compute a sum of Ramanujan
Srinivasa Ramanujan defined the following function: Write a function to compute for various values of . See also Cody Proble...

11일 전

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Matrix convolution
A certain convolution step involves an elementwise multipication between two 3x3 matrices and taking the resulting sum of the el...

13일 전

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Matrix Indexing
Given a matrix A and scalars r,c,i, find the product of two elements, with the first element located at row r and column c (doub...

13일 전

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Row operations
Given a matrix A and scalars m and n, add the mth row to the nth row. You can assume that the values of m and n are reasonable. ...

14일 전

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Switch two elements in vector
Exchange the elements in the mth and nth positions in a given vector v. Thus, if m = 1, n= 4 and v = [23 1 4 5 10], then the res...

14일 전

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Stacking vectors into a matrix
Given a 4x1 vector a, and a 2x2 matrix b, create a matrix M in which the first 2 rows are each identical to a and the last two r...

14일 전

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Vector creation using colon operator
Create a vector y containing n uniformly spaced values between a and b, with a < b. Use the colon (:) operator.

14일 전

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Vector creation using linspace
Create a vector y containing n uniformly spaced values between a and b, with a < b. Use linspace.

14일 전

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Logarithmically spaced vector creation using logspace
Create a vector y containing n logarithmically spaced values between a and b, with a < b. Use the logspace operator.

14일 전

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Logarithmically spaced vector creation using linspace
Create a vector y containing n logarithmically spaced values between a and b, with a < b. Avoid using logspace and use the linsp...

14일 전

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Right shift an array n times with constant space.
Right shift an array n times with constant space, that is, no extra array can be used. Right shift operation: Last element com...

15일 전

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Function - Cylinder Surface Area
The goal

15일 전

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Determine the average number of rounds for the following game.
Each round a uniformly distributed random number is picked between 0 and 1. The game ends when the sum of the random numbers is ...

16일 전

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preventing a war!!
essume you are a student and your family paid a lot of money for your classes but unfortunately the online classes made you a ...

16일 전

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Find the smallest integer m such that n divides m!
Write a function that takes an integer and finds the smallest integer whose factorial is divisible by . For example, if , then...

16일 전

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Find the number of days in a given year
Given a year number (eg. 2000) as input, find how many days are there in the given year.

18일 전

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Who am I ?
Who am I ? Write any function that reveals itself under these constraints. Hint: I am combinatorial code, and I don't like stat...

22일 전

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Find the sum of the following series
A(n)=(n*(n-1)!)/(n-2)!

23일 전

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Solve an ODE: equation C
Write a function to solve the following ordinary differential equation: with and . The parameter is a constant. The functi...

23일 전

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Count unique orderings of vertices of a polygon
Cody Problem 2671 asks us to determine whether four points can be the corners of a rectangle. The points are not necessarily inp...

24일 전

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Sum the elements in rows of the Levine triangle
The Levine triangle starts as follows: Row 0: 2 Row 1: 1 1 Row 2: 1 2 Row 3: 1 1 2 To construct each row, r...

28일 전

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Determine when snow started
R.P. Agnew posed the following problem: It starts snowing in the morning and continues steadily throughout the day. A snowplow t...

28일 전