39 total contributions since 2013

Professional Interests: Biostructural Research, Protein Science, SAXS, XTAL, NMR

Question

LSQLIN gives error even when A\b works

Hello everyone i have a set of linear equations which i would like to solve. My data consist of two matrices, Components and ...

2 years ago | 2 Answers | 0

Question

Error with anonymous call: Undefined function "times" for function_handle

Hello everyone i have a quite long formula which i have attempted to split up into two separate functions. I would then like ...

3 years ago | 0 Answers | 0

Solved

radius of a spherical planet

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

3 years ago

Solved

surface of a spherical planet

you just discovered its circumference, that is the input.

3 years ago

Solved

Sum all integers from 1 to 2^n

Given the number x, y must be the summation of all integers from 1 to 2^x. For instance if x=2 then y must be 1+2+3+4=10.

3 years ago

Solved

Most nonzero elements in row

Given the matrix a, return the index r of the row with the most nonzero elements. Assume there will always be exactly one row th...

3 years ago

Solved

Find the numeric mean of the prime numbers in a matrix.

There will always be at least one prime in the matrix. Example: Input in = [ 8 3 5 9 ] Output out is 4...

3 years ago

Solved

Finding Perfect Squares

Given a vector of numbers, return true if one of the numbers is a square of one of the other numbers. Otherwise return false. E...

3 years ago

Solved

The Goldbach Conjecture

The <http://en.wikipedia.org/wiki/Goldbach's_conjecture Goldbach conjecture> asserts that every even integer greater than 2 can ...

3 years ago

Solved

Weighted average

Given two lists of numbers, determine the weighted average. Example [1 2 3] and [10 15 20] should result in 33.333...

3 years ago

Solved

Remove any row in which a NaN appears

Given the matrix A, return B in which all the rows that have one or more <http://www.mathworks.com/help/techdoc/ref/nan.html NaN...

3 years 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".

3 years ago

Solved

Create times-tables

At one time or another, we all had to memorize boring times tables. 5 times 5 is 25. 5 times 6 is 30. 12 times 12 is way more th...

3 years ago

Solved

Return the 3n+1 sequence for n

A Collatz sequence is the sequence where, for a given number n, the next number in the sequence is either n/2 if the number is e...

3 years ago

Solved

Fibonacci sequence

Calculate the nth Fibonacci number. Given n, return f where f = fib(n) and f(1) = 1, f(2) = 1, f(3) = 2, ... Examples: Inpu...

3 years ago

Solved

Determine whether a vector is monotonically increasing

Return true if the elements of the input vector increase monotonically (i.e. each element is larger than the previous). Return f...

3 years ago

Solved

Make a checkerboard matrix

Given an integer n, make an n-by-n matrix made up of alternating ones and zeros as shown below. The a(1,1) should be 1. Example...

3 years ago

Solved

Pizza!

Given a circular pizza with radius _z_ and thickness _a_, return the pizza's volume. [ _z_ is first input argument.] Non-scor...

3 years ago

Solved

Swap the first and last columns

Flip the outermost columns of matrix A, so that the first column becomes the last and the last column becomes the first. All oth...

3 years ago

Solved

Find all elements less than 0 or greater than 10 and replace them with NaN

Given an input vector x, find all elements of x less than 0 or greater than 10 and replace them with NaN. Example: Input ...

3 years ago

Solved

Triangle Numbers

Triangle numbers are the sums of successive integers. So 6 is a triangle number because 6 = 1 + 2 + 3 which can be displa...

3 years ago

Solved

Determine if input is odd

Given the input n, return true if n is odd or false if n is even.

3 years ago

Solved

Select every other element of a vector

Write a function which returns every other element of the vector passed in. That is, it returns the all odd-numbered elements, s...

3 years ago

Question

Cannot declare a costum fit type using a function file

Hello everyone i have some experimental data i would like to try to fit a theoretical model to. specifically, i have a data-c...

3 years ago | 0 Answers | 0

Responded

Re: replacing negative values wit NaN

that must have been problem. i should know better, but i guess it slipped when i was fooling around trying to sort it out how to...

4 years ago | 8019 views

Responded

Re: replacing negative values wit NaN

Thanks for all the help i tried implementing your solution d{1,2}.data(d{1,2}.data(:,2)>0.9,2)=nan; (your example) d{1,k}.data(...

4 years ago | 8019 views

Question

Cannot find the plot options for LinearModels.fit using a constant

I have some x,y data that may or may not show a plateau depending on experimental conditions. Where the plateau shows up on the ...

4 years ago | 0 Answers | 0

Question

Adding legend in a plot genereted by a loop

Hello everyone i have a lot of x,y data sets that i would like to plot. The data sets are stored in a cell structure so that ...

4 years ago | 1 Answers | 0

Responded

Re: replacing negative values wit NaN

I'm reviving this thread because i have the same problems. i have three column data (x,y,stdev) and i want to replace the few ne...

4 years ago | 8019 views