new_arm: Generate Arm Object
In dfcorbin/MABsim: Run (contextual) Multi-Armed Bandit Simulations

Generate Arm Object

1	new_arm(reward_fun, sd, J, alpha = 1, a = 3, b = 1)

`reward_fun`	A function that takes a single argument, and outputs the expected reward of choosing this arm.
`sd`	The standard deviation of the arm rewards.
`J`	The number of basis functions to model this arm with.
`alpha`	A scaling parameter for the prior variances. The prior variance of the i'th model coefficient is given by i^-alpha (the intercept is the 0'th coefficient, and has a prior variance of 1).
`a`	The shape parameter for the inverse gamma distribution.
`b`	The scale parameter for the inverse gamma distribution.