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Something that really clicked was taking physics and chemistry classes with an HP RPN calculator. You typically rearrange your equations, factor label, substitu
by imglorp 4y ago
Something that really clicked was taking physics and chemistry classes with an HP RPN calculator. You typically rearrange your equations, factor label, substitute values, and calculate: plug-and-chug. We had races and the HP's always beat the TI's and Casio's because you don't need to mess with parens. You might enter a parenthesized expression first and then work outwards.
- martyalain 4y agoA long time ago I was able to write on my HP67 a complete program for calculating the compression, tension and bending forces of a continuous beam on supports (for example a railway rail on sleepers), applying the equations I learned in my engineering school. In fact it was the first time I understood something about this equation. Until I translated it into code I only knew the music, not the details. That's why, when I explore a code, here the evaluation of an RPN expression, I try to keep the foundations to a minimum. The minimum minimorum is the lambda-calculus. Many code examples use the subtleties of this or that language, with the drawback of hiding the fundamental structure of the algorithm. For these reasons I prefer the "list" version to the "array" version. Basically nothing else than the three fundamental "cons, car, cdr". I am interested in your opinion.