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Shunting Yard and Evaluation of expression in c++ pseudo code 9 Years Ago by Joemeister … a infix mathematical expression into a postfix expression using the shunting yard algortihm but can only get so far by writing the… be able to help me. This is my pseodo code: Shunting Yard: string shuntingYard(string expression) { string postFix = ""; //An initially… Re: Shunting Yard and Evaluation of expression in c++ pseudo code 9 Years Ago by L7Sqr I wrote a code snippet (in C++) not too long ago for doing just this. You can find it [here](http://www.daniweb.com/software-development/cpp/code/427500/calculator-using-shunting-yard-algorithm) Calculator using shunting-yard algorithm 11 Years Ago by L7Sqr …, converts them to reverse polish notation by way of the shunting-yard algorithm and then evaluates the resulting expression. I tried to… theory, they could be pulled out and used independently. The shunting-yard behavior is provided via `class ShuntingYard`; I used the visitor… Re: Calculator using shunting-yard algorithm 11 Years Ago by happyuk Nice article! For coding up the Shunting Yard algorithm I personally found the following Wiki pages very useful: …http://en.wikipedia.org/wiki/Shunting-yard_algorithm http://en.wikipedia.org/wiki/Reverse_Polish_notation So long as… Re: Shunting Yard and Evaluation of expression in c++ pseudo code 9 Years Ago by Joemeister Awesome code! Thank you! My other problem now is in my main.cpp I have a string like this: #include <iostream> #include "Expression.h" using namespace std; int main() { /* Creating Expression objects. Notice that all operators and operands are seperated by spaces. This will … Re: Shunting Yard and Evaluation of expression in c++ pseudo code 9 Years Ago by L7Sqr Without seeing the `Expression` class I'd assume to construct the following: class Expression { std::map< std::sring, double > symtab_; // ... public: double instantiateVariable (const std::string &var, double val) { std::map< std::string, double >::iterator sti = symtab_.find (var);… Re: Shunting Yard and Evaluation of expression in c++ pseudo code 9 Years Ago by Joemeister Oh yeah sorry about that! Here is my class and it's members. #ifndef EXPRESSION_H #define EXPRESSION_H #include <string> #include <iostream> using namespace std; class Expression { private: //...; public: /*The constructor receives a string expression in infix… Re: Shunting Yard and Evaluation of expression in c++ pseudo code 9 Years Ago by L7Sqr That is just the interface you are exposing. My comment was more to the point of not knowing what you had already implemented. Regardless, you can use the symbol table idea I provided above to manage the expression internals (variables, values, etc.). As I mentioned in your other post, propagating the expression as a string is a bad idea; it … Re: Shunting Yard and Evaluation of expression in c++ pseudo code 9 Years Ago by Joemeister Currently, in your program. The infix does not contain any variables for ex. x * (2 + 3) and it only uses digits. How can I instantiate the variables in the expression (with a function) - giving the x, for example a value. AND then continue with the "new" infix, where the values are added? Re: Shunting Yard and Evaluation of expression in c++ pseudo code 9 Years Ago by iamthwee Couldn't you just substitute the variables for numbers before you do anything? Surely it would be a simple string replace. Re: Calculator using shunting-yard algorithm 11 Years Ago by mike_2000_17 This is very nice! It's a neat little piece of designed code to solve a somewhat simple problem but in a fairly generic way. That's cool, it's the kind of code I like to see. As usual, I could point out a few things to improve. At least, there is one thing that could be a nice improvement to this design and other similar designs (as this is a … Re: Calculator using shunting-yard algorithm 11 Years Ago by iamthwee Nice snippet. Mike makes some really good points about the semantics of the language you have used to program this in. I'm going to make a few suggestions about the practical use of this... Bear in mind I haven't tested your code completely at all so other issues may exist. Your code falls flat on it's face when unary operators are considered.… Re: Calculator using shunting-yard algorithm 11 Years Ago by L7Sqr @mike_2000_17: Thank you for taking the time to provide the feedback you did! I agree with decoupling the `Calculator` and `TokenBase` and just didn't consider it as I was writing the code. As for the reduction of the switch to a more maintainable construct - I really like the approach you suggested. I toyed with a way to make that better but … Re: Calculator using shunting-yard algorithm 11 Years Ago by TrustyTony I think better approach would be to just 'transparentely add +'. I mean that you do not have substraction routine but enter adding with negation flag set for number scanner. Then you just toggle the negation flag for minus ignoring plusses. That could be handled by suffiently competent number parser. > Not quite as aesthetically pretty as… drawing with c++ 14 Years Ago by AirGear … the equation. I already implemented Reverse Polish Notation, and also shunting-yard algorithm. But, i found out that all my friends focused… user int ukuranPost=0; //banyak sel post yang terisi double shunting(double); //shunting-yard algorithm void postfix(string); //mengubah infix menjadi postfix double… ADT Tree Building + Parseing user Input 13 Years Ago by Annuate … the [URL="http://http://en.wikipedia.org/wiki/Shunting-yard_algorithm"]Shunting-yard algorithm[/URL]. This will take infix notation and convert… Receiving stack errors when trying to evaluate a postfix expression 9 Years Ago by Joemeister … parameter is a postfix string that was done through a shunting yard algorithm and is now passed through to the evaluate function… Easiest way to implement this in Java 9 Years Ago by nataraja833 … (i.e 1,0,x ) . Currently I'm thinking of Shunting Yard Alogo to create the string from infix to posix notiation… Re: Easiest way to implement this in Java 9 Years Ago by Taywin … take up the most code line is the parsing. In Shunting yard, it simply converts a string to posix notation. If you… Re: Please help about to postfix statement conversion 15 Years Ago by Salem Shunting yard algorithm Re: compile c++ using another c++ file 14 Years Ago by AirGear … post yang terisi string input; double xkiri,xkanan; double shunting(double); //shunting-yard algorithm void postfix(); //mengubah infix menjadi postfix double convert… x kanan : "; cin>>xr; fxl=shunting(xl); fxr=shunting(xr); } else { cout<<"Tidak ada … Re: Infix to postfix using queue 14 Years Ago by quuba …] [QUOTE]Converting from infix notation Main article: Shunting-yard algorithm Edsger Dijkstra invented the Shunting-yard algorithm to convert infix expressions to postfix (RPN…), so named because its operation resembles that of a railroad shunting yard. There are other ways of producing postfix expressions from infix… Re: binary integer logic 17 Years Ago by p_eqlz_np … for evaluation RPN-style is rather fast (using a "shunting yard" algorithm, read it up) and is rather easy to… i have actually been doing so far is implementing the shunting yard algorithm. Re: Code Snippet Contest 11 Years Ago by L7Sqr My submission. A simple [calculator](http://www.daniweb.com/software-development/cpp/code/427500/calculator-using-shunting-yard-algorithm). Internally uses reverse polish notation format generated using shunting-yard algorithm. Re: C++ calculator problem 12 Years Ago by L7Sqr [QUOTE=thecoolman5;1626900] How would you do it?[/QUOTE] I'd start by removing [i]all[/i] the [icode]goto[/icode]s. From there I would look at the [url=http://en.wikipedia.org/wiki/Shunting-yard_algorithm]Shunting-Yard algorithm[/url]. Re: I want to create a calculator on c sharp 12 Years Ago by gusano79 For the math part, read about the [shunting-yard algorithm](http://en.wikipedia.org/wiki/Shunting-yard_algorithm). Re: Advanced string functions, math generator 11 Years Ago by gusano79 I think you'll get the most value out of working with [parse trees](http://en.wikipedia.org/wiki/Parse_tree) of the expressions rather than trying to do it all with string manipulation. For reading in text equations, have a look at the [shunting-yard algorithm](http://en.wikipedia.org/wiki/Shunting-yard_algorithm). Re: evaluvation of arithmetic expressions 11 Years Ago by Gonbe … formula's you might want to look at Dijkstra's Shunting Yard algorithm. Information on this can be found here: http://en… Re: MDAS Program help. 11 Years Ago by Gonbe That's somewhat complex for someone learning C. An algorithm I'd use for parsing these kind of formula's would be the [Shunting-yard algorithm](http://en.wikipedia.org/wiki/Shunting-yard_algorithm) by Dijkstra. The article contains example code for C too. Re: Parsing Implementation - Algebra Parsing Advice? 10 Years Ago by gusano79 … approach to parsing algebraic expressions is the [shunting-yard algorithm](http://en.wikipedia.org/wiki/Shunting-yard_algorithm). It's powerful enough to deal…