Community Profile

# William

##### Last seen: Today
4,772 total contributions since 2012

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

View all

Contributions in
View by

Solved

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 ...

5 days ago

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...

7 days ago | 2

Solved

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

7 days ago

Solved

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

9 days ago

Solved

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...

9 days ago

Solved

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. ...

10 days ago

Solved

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...

10 days ago

Solved

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...

10 days ago

Solved

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.

10 days ago

Solved

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

10 days ago

Solved

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.

10 days ago

Solved

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...

10 days ago

Solved

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...

11 days ago

Solved

Function - Cylinder Surface Area
The goal

11 days ago

Solved

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 ...

12 days ago

Solved

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 ...

12 days ago

Solved

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...

12 days ago

Solved

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.

14 days ago

Solved

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...

18 days ago

Solved

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

19 days ago

Solved

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

19 days ago

Solved

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...

20 days ago

Solved

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...

24 days ago

Solved

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...

24 days ago

Solved

Eliminate redundant numbers in text
Occasionally someone might write text such as Briefly explain one (1) common problem that can result from the constant use of ...

25 days ago

Solved

Solve an ODE: equation B

29 days ago