I've been looking at the wiki page: http://en.wikipedia.org/wiki/Shunting-yard_algorithm
I've used the code example to build the first part, basically I can currently turn :
3 + 4 * 2 / ( 1 - 5 ) ^ 2 ^ 3
into 3 4 2 * 1 5 − 2 3 ^ ^ / +
But I don't know how to then use 3 4 2 * 1 5 − 2 3 ^ ^ / +
to obtain 3.00012207
And the example code and explanation on wiki aren't making any sense to me.
Could someone please explain how to evaluate 3 4 2 * 1 5 − 2 3 ^ ^ / +
and produce the answer. Thanks in advance. I don't need a code example just a good explanation or a breakdown of an example.
Not that it matters but I am working .net C#.
The purpose of the shunting yard algorithm is that its output is in Reverse Polish Notation, which is straightforward to evaluate:
I see I am a bit late to the party.
I saw the question and went off on a tangent writing a couple of tasks for Rosetta Code. It just so happens that this task might be what you are after. It gives an annottated table of what happens when calculating the value of an RPN expression, token by token.
Here is a sample of its output:
Process the elements
3 4 2 * 1 5 − 2 3 ^ ^ / +
left-to-right as follows:When you get to the end, the stack should have a single element which will be the result.
The post-fix notation is how you do the math in, say, a HP calculator.
Keep a stack, whenever you get a number add it to the top. Whenever you get an operator consume inputs from the top and then add the result to the top