price_adjusted_portfolio: renormalizes portfolio to show total portion of wealth in...
In benSepanski/pfselect:

Starting with a portfolio whose ith entry was the portion of ones total wealth in asset i for the previous prices, return a new vector reflecting the portion of total wealth in each asset under the new prices.

1	price_adjusted_portfolio(portfolio, tp_price_relatives, .check_input = TRUE)

`portfolio`	A vector of non-negative numbers which sum to 1, the ith entry representing the portion of total wealth in asset i.
`tp_price_relatives`	A vector whose ith entry is the ratio of the ith asset's new price to its old price at the end of this trading period. More precisely, if asset i had price p_{t-1} when wealth was distributed according to `portfolio`, but now has price p_t, the ith entry of `price_relatives` is \frac{p_t}{p_{t-1}}.
`.check_input`	If `TRUE`, checks that input meets the given assumptions.