You mean coin switching, not so much algorithm switching.
There are a couple ways to mine with prohashing.
1. PPS: Mine an algorithm(s) and select what coin(s) and percentages you want to be paid in. For instance, I have scrypt, x11, and sha-256 miners running, but am getting paid in BTC right now. I've done blends of coins including BTC, BCH, LTC, DOGE, CLAM, etc in the past. This method is a good way to build a portfolio. The benefit is you don't have to mess with an exchange (like ultiman2 said). The only time you have to worry about your algorithm is if your connecting to the proxy server on port 443. Otherwise just use the algorithm specific port in the address.
a. PPS (single coin): If you have problems with coin switching you can use the
password argument to mine a single coin. This method may not be the most efficient way to make $$ with PPS as you can end up mining less profitable coins when profitability changes. Also it is important to have a failover pool when you use single coin mining. Other wise if the coin you chose falls into error you won't be making $$.
2. Solo: You use the
and
password arguments (Visit the help page for more info) to set what coin you want to solo mine. You get paid only in that coin when you find a block or when you submit a share that credits you for merged mined coins. The pool cut is less with this method, because the miner takes on the risk of bad luck.