PDF and CDF of sum of two independent $\Gamma$-distributed random variables [duplicate]

Let $X \sim \Gamma(m, p)$ with a shape parameter $m$ and a scale parameter $p$ and $Y \sim \Gamma(m, q)$ with a shape parameter $m$ and a scale parameter $q$, and let $X$ and $Y$ be independent.

What will be the PDF and CDF of $X+Y$? How can I solve it in MatLab?

• Notation comment: $\Gamma$ is used rather for denoting the gamma function and gamma distribution is rather written simply as "gamma".
– Tim
Jan 14, 2016 at 9:02