I need a function that returns the smallest prime number p smaller than 100,000 such that (p + n) is also prime, where n is a scalar integer and is the sole input argument to the function

Write a function called prime_pairs that returns the smallest prime number p smaller than 100,000 such that (p + n) is also prime, where n is a scalar integer and is the sole input argument to the function. If no such number exists, then the function returns -1. You may use the built-in functions, primes and isprime.

[Walter Roberson]

http://www.mathworks.com/matlabcentral/answers/6200-tutorial-how-to-ask-a-question-on-answers-and-get-a-fast-answer

[Adam]

Write such a function then!

[Image Analyst]

http://www.mathworks.com/matlabcentral/answers/8626-how-do-i-get-help-on-homework-questions-on-matlab-answers

Answer 1

[Stephen23]

function p = prime_pairs(n)
V = primes(1e5);
V = V(isprime(n+V));
if isempty(V)
  p = -1;
else
  p = V(1);
end
end

Answer 2

[charu sharma]

For simple code refer this and ask if you have any query: http://farzicoders.blogspot.in/2015/08/write-function-called-primepairs-that.html

[Stephen23]

"simple code" with:

• poorly named variables: for i=1:l
• superfluous intermediate variables: flag
• superfluous loops when code vectorization would be neater.
• superfluous return statements.