LTSpice: where can I get an overview of expressions?

Discussion in 'General Electronics Chat' started by cspwcspw, Nov 23, 2016.

  1. cspwcspw

    Thread Starter Member

    Nov 8, 2016
    Hi. Many of the LTSpice tutorials are great, but they tend to show worked examples or single techniques. So I might learn how to step a parameter, or write an expression that varies some simulation parameter of a component.

    But I'm missing a general overview and perhaps a formal specification of how the syntax works. So when I need to write X as opposed to {X} or .param X = <expression> or it all needs to be quoted or in extra brackets, I am on thin ice. And that includes when using a label, when I need the keyword param, etc. etc.

    I'm from a computer language background, so I'm probably more comfortable with formal or semi-formal syntax rules like BNF notation, or even the old Pascal railroad diagrams.

    Can anyone recommend a resource that summarizes (and perhaps overviews) how the definitions and expressions work, and how expression evaluation happens? (I think I get the bit that the language is "a symbolically declarative language") but I find quite of lot of fuzziness and folk on the internet saying things like "I found experimentally that e1 ? e2 : e3 is equivalent to if(e1, e2, e3)" or "the curly braces and square brackets are substitutable" (I doubt this is correct).

    At the moment my education on LTSpice seems to be happening "piece-meal". Can anyone suggest a kind of "reference resource" or decent "cheat sheet" for LTSpice syntax?

  2. eetech00

    Senior Member

    Jun 8, 2013
    Probably the best resource for this kind of stuff is the LTspice yahoo group
  3. mtonge


    Apr 19, 2016
    I just checked Amazon books, and there are several publications for LTSpice IV. I'm surprised that, since LTSpice XVII was released this year, that there are no current books for it. Go figure.