Community Profile

# Daniel Warren

### University of Oxford

71 total contributions since 2013

I'm a postdoctoral physicist at Oxford University.

View details...

Contributions in
View by

Solved

Return a list sorted by number of occurrences
Given a vector x, return a vector y of the unique values in x sorted by the number of occurrences in x. Ties are resolved by a ...

ungefär 4 år ago

Solved

Which doors are open?
There are n doors in an alley. Initially they are all shut. You have been tasked to go down the alley n times, and open/shut the...

ungefär 4 år ago

Solved

Too mean-spirited
Find the mean of each consecutive pair of numbers in the input row vector. For example, x=[1 2 3] ----> y = [1.5 2.5] x=[1...

ungefär 5 år ago

Solved

Create a row array using double colon operator
Create a row array from 9 to 1, using the double colon operator.

ungefär 5 år ago

Solved

Distance walked 1D
Suppose you go from position 7 to 10 to 6 to 4. Then you have walked 9 units of distance, since 7 to 10 is 3 units, 10 to 6 is 4...

ungefär 5 år ago

Solved

Fahrenheit to Celsius using multiple statements
Given a Fahrenheit value F, convert to a Celsius value C. While the equation is C = 5/9 * (F - 32), as an exercise use two state...

ungefär 5 år ago

Solved

How to find the position of an element in a vector without using the find function
Write a function posX=findPosition(x,y) where x is a vector and y is the number that you are searching for. Examples: fin...

ungefär 5 år ago

Submitted

Trace perimeter of binary image with line segments (bwperimtrace)
Traces the outer boundaries of non-zero pixels in a monochrome image

Solved

you just measured its surface area, that is the input.

mer än 5 år ago

Solved

Reverse Run-Length Encoder
Given a "counting sequence" vector x, construct the original sequence y. A counting sequence is formed by "counting" the entrie...

mer än 5 år ago

Solved

Making change
Given an amount of currency, return a vector of this form: [100 50 20 10 5 2 1 0.5 0.25 0.1 0.05 0.01] Example: Input a = ...

mer än 5 år ago

Solved

Counting Money
Add the numbers given in the cell array of strings. The strings represent amounts of money using this notation: \$99,999.99. E...

mer än 5 år ago

Solved

De-dupe
Remove all the redundant elements in a vector, but keep the first occurrence of each value in its original location. So if a =...

mer än 5 år ago

Solved

Elapsed Time
Given two date strings d1 and d2 of the form yyyy/mm/dd HH:MM:SS (assume hours HH is in 24 hour mode), determine how much time, ...

mer än 5 år ago

Solved

Calculate trends in time series
Create a new variable that has trends in input series. If _t+1_ is bigger than or equal to _t_, than trend in _t_ will be 1, oth...

mer än 5 år ago

Solved

Subtract 12 from x
given a number x, return y, which is x - 12

mer än 5 år ago

Solved

Right and wrong
Given a vector of lengths [a b c], determines whether a triangle with those sides lengths is a right triangle: <http://en.wikipe...

mer än 5 år ago

Solved

The Hitchhiker's Guide to MATLAB
Output logical "true" if the input is the answer to life, the universe and everything. Otherwise, output logical "false".

mer än 5 år ago

Solved

Circle area using pi
Given a circle's radius, compute the circle's area. Use the built-in mathematical constant pi.

mer än 5 år ago

Solved

Simple equation: Annual salary
Given an hourly wage, compute an annual salary by multiplying the wage times 40 and times 50, because salary = wage x 40 hours/w...

mer än 5 år ago

Solved

Balanced number
Given a positive integer find whether it is a balanced number. For a balanced number the sum of first half of digits is equal to...

mer än 5 år ago

Solved

Replace NaNs with the number that appears to its left in the row.
Replace NaNs with the number that appears to its left in the row. If there are more than one consecutive NaNs, they should all ...

mer än 5 år ago

Solved

Quote Doubler
Given a string s1, find all occurrences of the single quote character and replace them with two occurrences of the single quote ...

mer än 5 år ago

Solved

Pangrams!
A pangram, or holoalphabetic sentence, is a sentence using every letter of the alphabet at least once. Example: Input s ...

mer än 5 år ago

Solved

Binary numbers
Given a positive, scalar integer n, create a (2^n)-by-n double-precision matrix containing the binary numbers from 0 through 2^n...

mer än 5 år ago

Solved

Duplicates
Write a function that accepts a cell array of strings and returns another cell array of strings *with only the duplicates* retai...

mer än 5 år ago

Solved

Remove all the consonants
Remove all the consonants in the given phrase. Example: Input s1 = 'Jack and Jill went up the hill'; Output s2 is 'a ...

mer än 5 år ago

Solved

Find the longest sequence of 1's in a binary sequence.
Given a string such as s = '011110010000000100010111' find the length of the longest string of consecutive 1's. In this examp...

mer än 5 år ago

Solved

Find the alphabetic word product
If the input string s is a word like 'hello', then the output word product p is a number based on the correspondence a=1, b=2, ....

mer än 5 år ago

Solved

Pascal's Triangle
Given an integer n >= 0, generate the length n+1 row vector representing the n-th row of <http://en.wikipedia.org/wiki/Pascals_t...

mer än 5 år ago