Comment Logicalness of postfix (Score 1) 580
For me, it was about being logical. I first laid hands on an infix calculator in about 1970. I could not make it work! I was used to mechanical calculators for which you entered a first operand and a second and then commanded an operation on them. With the newfangled electronic calculator, it never occurred to me to specify the operation before I had specified both operands. I finally asked a salesperson in a department store, "How do you make this thing work?", and I got a response like, "You know - '1' '+' '2' '=': See?: 3". Being a mathematician, I was embarrassed; but I was able to grasp the infix concept quickly enough. However, when I got my hands on an HP calculator, I was much happier. At one point, I had got my company to buy me a programmable TI calculator (with removable program medium), thinking it was a much better deal than the comparable HP. However, I was so annoyed with the infix notation that I insisted on returning the TI so I could get the more expensive postfix HP. We're talking here about prices in the several $100s.
The infix calculators are OK if you are punching in a fully formed expression which you are reading. However, if I am just thinking and calculating as I go, I find the postfix way to be much easier to keep track of - as I can do operations as I think of them, and I do not have to think about operand grouping or think ahead because of it. For me in postfix mode, it is more like a succession of "Do this to the number I have got so far." Conceptually, I am operating directly on intermediate results as opposed to evaluating an expression which already existed in some sense.
One problem I have with infix calculators is that they are not consistent in the way they implement operation hierarchy. Eg., on some, 2+2/2 would produce a result of 3 and, on others, 2. (I actually prefer 2 in this case, as I do not want to have to think about a stack of pending operations when it cannot be presented in an obvious manner.) On an unfamiliar infix calculator, I wind up putting in potentially unnecessary parentheses just to be safe.
PS - I apologize for my "testing" posting. I really did hit "Preview" as I wanted to test my login. I don't know what went wrong, but it probably had something to do with the fact that I was not yet logged in.
The infix calculators are OK if you are punching in a fully formed expression which you are reading. However, if I am just thinking and calculating as I go, I find the postfix way to be much easier to keep track of - as I can do operations as I think of them, and I do not have to think about operand grouping or think ahead because of it. For me in postfix mode, it is more like a succession of "Do this to the number I have got so far." Conceptually, I am operating directly on intermediate results as opposed to evaluating an expression which already existed in some sense.
One problem I have with infix calculators is that they are not consistent in the way they implement operation hierarchy. Eg., on some, 2+2/2 would produce a result of 3 and, on others, 2. (I actually prefer 2 in this case, as I do not want to have to think about a stack of pending operations when it cannot be presented in an obvious manner.) On an unfamiliar infix calculator, I wind up putting in potentially unnecessary parentheses just to be safe.
PS - I apologize for my "testing" posting. I really did hit "Preview" as I wanted to test my login. I don't know what went wrong, but it probably had something to do with the fact that I was not yet logged in.
