Write a program to produce the probability density function of binomial distribution

i.e. a function that only returns 2 possible values(0 and 1). The probability of returning 0 is p, the probability returning 1 is q. where p + q = 1

[Walter Roberson]

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

Answer 1

[Star Strider]

One approach:

R = @(p,n) rand(1,n) > (1 - p);                     % Probability = p, Number Of Trials = n

Trials = R(0.2, 50);

[Vin Sen Lee]

hi could you please explain your code. I don't really get it. thank you

[Star Strider]

The rand functions produces uniformly-distributed random numbers from 0 to 1. My little function tests to see if that value is greater than ‘q’, and if so, defines as a logical value of 1. Otherwise, it is defined as zero. (Logical values are automatically converted to double values if you use them in a calculation.)

The rand function can produce a vector of such random values, so I added the ‘n’ argument to tell it how long a vector to produce. (The ‘n’ value must be an integer.) This avoids your needing to call it in a loop to generate a vector of random values. If you only need one value, set ‘n’ to 1.

EDIT — To clarify, my function does not generate a binomial distribution. It yields a Bernoulli trial. A binomial distribution is the sum of such trials. See the binornd function for binomial random numbers.