S3 Gamma Densities
Depending on the parameters p and lambda, the Gamma density can take different shapes, as depicted in the diagram below. The shape parameter p is denoted k, and the scale parameter lambda is written as theta, in the following diagram, taken from Wikipedia entry on the Gamma Distribution
Above images for different types of Gamma densities are taken from the Wikipedia article on Gamma Densities
k, theta correspond to p and lambda
IMAGE CREDIT TO:
By Gamma_distribution_pdf.png: MarkSweep and Cburnettderivative work: Autopilot (talk) - Gamma_distribution_pdf.png, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=10734916.