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 Subject: Equation code, need help Category: Computers Asked by: unlimitedxp-ga List Price: \$50.00 Posted: 05 Nov 2004 22:53 PST Expires: 05 Dec 2004 22:53 PST Question ID: 425157
 ```For this programming project it will create a calculator to represent the polynomials using linked lists, where each node of the linked list will contain the information of a term: a coefficient and the exponent of the variable. For example to represent a polynomial 5 - 3x^4 + 2x^2 + 5x^3, the first node will have a coefficient 5 and exponent 0, the second node will have a coefficient 3 and exponent 4, and so forth. Combine like terms: combining like terms is to add the coeffcient of those terms with the same exponent For example, combining the like terms of x^2 + x^2 + 3x results in 2x^2 + 3x. Addition adding two polynomials is simple to add like terms of both polynomials. For example(x^2 + x^3 + 1) + (x + 2x^2 + 2) is equal to x + 3x^2 + x3 + 3. Substraction: to substract two polynomials you substract the coefficient of a term of the second polynomial to the coefficient of the like term of the first polynomial. For example(x^2 + x^3 + 1) - (x + 2x^2 + 2) is equal to -x -x^2 + x3 - 1. Input will be taken from the user. The calculator will prompt the user for an input and the user can enter two kind of inputs: commands or polynomials. If the user enters a command, your calculator should pop the requiered number of operands from the stack, perform the opeation, and push the result of the operation into the stack such as "c": should combine the terms of the polynomial at the top of the stack, +: should add the two polynomials at the top of the stack, -: should substract the second to top polynomial minus the polynomial at the top of the stack *: should multiply the two polynomials at the top of the stack. When entering polynomials, the user should use the following format, each term should be separetad by + or -, the coeffcient should be separated from the variable by a space, the variable and exponent should be connected by ^ and x is the only valid variable. The following polynomial must be such like 2 x^3 + 3 x^1 + 4 x^0. The classes must be Term: Objects of this class can be used to store the information of a term, each term needs two values; a coefficient and the exponent of the variable, LinkedList: objects of this class will be used to cantain the terms of your polynomials linked list objects are responsible for the standard linked list operation: insert, find and delete. This class must be generic data structe, you will be able to insert any objects. Polynomials: objects of this class are responsible for storing a polynomials information using a linked list. It is not a requierement for a polynomials term to be ordered by degree. Also Polynomial objects should be able to perfor operations add, substract and multiply given another polynomial object. Stack: Objects of this class will contain the operands of your calculator. Stack objects are responsible for the standard stack operations, push, pop, peek, isEmpty and isFull and it also must be a generic data structure anf for last is the PolynomialCalculator: objects of this class should use a stack to store the operands and will perform the operations requested by the user. Therefore, objects of this class are responsible for the calculators operations: combine, add, substract, multiply, and add operands. The main class will be in charge of receiving input from the user, interpreting the input, and sending the appropriate commands to the calculator. The application should also display the output back to the user. I will need it on Saturday November 6 or Sunday November 7. Can you please send me the answer to my email unlimitedxp1@yahoo.com, not post the answer.``` Clarification of Question by unlimitedxp-ga on 06 Nov 2004 07:22 PST ```Dear probonopublico I did not, that posting was against the rules, sorry for that. If you want, you can post the solution, I would really appreciate the solution by today.``` Request for Question Clarification by endo-ga on 06 Nov 2004 08:21 PST ```Hi, What programming language do you want to use? This sounds a lot like homework, would you rather someone helps you start off a solution, rather than write it all for you? Thanks. endo``` Clarification of Question by unlimitedxp-ga on 06 Nov 2004 09:39 PST ```Dear endo-ga Its in java language. I am almost finished with the code, but there is some problems with my code. I just want another code to compare with in order to be able to figure it out what is wrong with mines. I really dont have time to start off again, I gotta turn in it by today, if you want I can send you my code and then you can also help me to figure it out what is wrong with it? or if you a code already done, you can also post it to see it. Thanks unlimitedxp``` Request for Question Clarification by endo-ga on 06 Nov 2004 11:05 PST ```Hi, I think I can help. I will look at your code and try and fix it. Post links to your code here, if you can upload them to a web server I can download them. If you don't have access to a webserver, please upload your files to: host: ftp.membres.lycos.fr username: dbky password: googleanswers Thanks. endo``` Clarification of Question by unlimitedxp-ga on 06 Nov 2004 12:28 PST ```Dear endo-ga I already uploaded the files to your ftp in word format, you just have to copy and paste them in your computer, or you can also open a notepad to save them in there as .cmd to compile them from there, either way. Please tell me if you already got them in order for you te be able to give it a look. Thank you for your help.``` Request for Question Clarification by endo-ga on 06 Nov 2004 12:37 PST ```Hi, Thanks, got them, trying to figure out what is what. If you can give a short explanation that would make things easier. Thanks. endo``` Request for Question Clarification by endo-ga on 06 Nov 2004 12:43 PST ```Hi, Also, please tell me what the problems are and where you think they are. Thanks. endo``` Clarification of Question by unlimitedxp-ga on 06 Nov 2004 13:31 PST ```Dear endo I ve got a problem at the moment of reading the numbers from the stack, because I did some tests in the main class to see what would be printing and the output waited for me, but as you can see in the output is completely different from the numbers that you are trying to compute with the contents of the stack. I think the problem could be with the main class that is not doing exactly what is created for. Then I also checked the values from t and f in the calculator class and it showed as a double and int, but the Tokenizer does not seems to go through the entire equation. There must be something wrong at the moment of reading an input. I ve got these results from these two System print out System.out.println(stacky); System.out.println(t +" " + f); . There is also a mistake in the polynomial class at line 95, there is a null value that is showing at the moment of running the main. Do not mind the last mistake a line 134 from calculator. Please enter the numbers that you need to compute: 4 x^ 5 + 6 x^ 2 +4.0*x^4 4.0 4 +4.0*x^4 +5.0*x^5 5.0 5 Exception in thread "main" java.lang.ClassCastException at Polynomial.add(Polynomial.java:95) at Calculator.main(Calculator.java:134)``` Clarification of Question by unlimitedxp-ga on 06 Nov 2004 13:32 PST ```If I can help you with anyquestions or concern please feel free to ask me.Thank you. unlimitedxp``` Request for Question Clarification by endo-ga on 06 Nov 2004 13:57 PST ```Hi, The files you sent are a bit confusing, there are several classes that are repeated several times. Could you please reupload the .java files as you are using them to compile and run the latest version you have. Thanks. endo``` Clarification of Question by unlimitedxp-ga on 06 Nov 2004 14:27 PST ```Did you get my java files yet? If you do then I will try explain it. Look, the last three java link lists are just one implemented linked list, but I did it in different way trying to have a better access to the stack. I ve got those numbers from trying to compile the calculator class and running it by writing java Calculator in the command prompt. You can also do any modifications that you think it would be necessary to do in order to make the program works correctly. Feel free to write me again for any regards or question. Thank you``` Request for Question Clarification by endo-ga on 06 Nov 2004 15:00 PST ```Hi, I got the Java files, thanks. I'll work on it soon. Thanks. endo``` Clarification of Question by unlimitedxp-ga on 06 Nov 2004 15:24 PST ```Dear endo Thanks to you``` Request for Question Clarification by endo-ga on 06 Nov 2004 16:46 PST ```Hi, Are you sure you sent me the latest versions of the files? There seems to be problems with the Stack and Polynomial classes, there are mising functions or incorrect calls to functions there. I can't compile them at the moment, they're missing code, otherwise it doesn't make any sense. Thanks. endo``` Clarification of Question by unlimitedxp-ga on 06 Nov 2004 23:08 PST ```I did some changes to the Polynomial classes, working withouth stacks, but the polynomial class is now working. I already update the files in your ftp, if you want it to check it out now. That was my actual version, because the stack class is created into the polynomial class without any callings, but there was a misunderstanding in my part to call an extra stack, but I saw in the assignment is necessary just to hold the operands of the calculator and the linked list is responsible to contain the terms of your polynomials. How can you mixed them up at the time of calling them into the polynomial class, anyways, but i could not really implement that part into code, I think all the calling is in the polynomial class. If you have something new about the code please tell me or if you have some other concerns or questions.``` Request for Question Clarification by endo-ga on 06 Nov 2004 23:15 PST ```Thanks, it compiles ok now. Is it if I work on this on Sunday? It's 7am now, and I haven't gone to sleep yet. Thanks. endo``` Clarification of Question by unlimitedxp-ga on 06 Nov 2004 23:29 PST ```Dear endo Thats all right, I mean i really appreaciate what you are doing to help me. Tomorrow is fine. Meanwhile, I will keep working on it, becuase in here is 12:28am. Thanks you``` Clarification of Question by unlimitedxp-ga on 06 Nov 2004 23:49 PST `I will add an extra List Price to this assignment.` Clarification of Question by unlimitedxp-ga on 07 Nov 2004 00:40 PST ```Dear probonopublico-ga Do you have a different way to solve it, because i did it in a way that I am still stuck, and I cannot figure it out, what is wrong with mines version. Do you already figured out.``` Clarification of Question by unlimitedxp-ga on 07 Nov 2004 00:45 PST ```I needed it really bad as fast as I can, not just to score some points in the grade, but to pass the class, becuase the due to turn in the project was on november 2. I have not finish it yet and they requiered me to turn in every single project and I am getting behind from the others at this time. I have to turn in the next one on tuesday, I would really appreaciate any help that you can give me probonopublico. Thank you``` Request for Question Clarification by endo-ga on 07 Nov 2004 11:02 PST ```Hi, I think I've got addition working. I've uploaded a new version of Calculator.java. I changed lines 105-116 in Calculator.java. The logic for reading the tokens was wrong, so you were casting a "+" sign into a Polynomial, hence the error. I'll have a look at multiplication now. Thanks. endo``` Clarification of Question by unlimitedxp-ga on 07 Nov 2004 11:16 PST ```Dear Endo That's really great!!! I am redoing the whole thing again in order to be able to search for a new perspectives. I was really lost, so I decided to start from the beginning in order to be able to think way ahead before to codify. If you want I can also upload all the new classes that I am doing for you to have a better perspective about what is going on. Thank you``` Request for Question Clarification by endo-ga on 07 Nov 2004 11:20 PST ```Hi, If you're starting over again, then I'll stop working on the old code. Let me know when you get stuck with your new code and I'll help you out. If you have a problem that you can't solve, upload the files again and I'll look. You can delete the old ones from the FTP too, to avoid any confusion. Let me know how it goes. Thanks. endo``` Clarification of Question by unlimitedxp-ga on 07 Nov 2004 12:10 PST ```I already uploaded all new files that I have now. You can give it a look and see if this version is better than the old version, because if is better is more convenient keep working on this version, but If you feel more comfortable working with the old version is also fine, either way. I think that in the new version I have a more complete linked list, but I am still having a problem the calculator method as you said before in the lines 105 to 116. There is also the problem that I don?t know how to implement the stack and the linked list together in the main calculator class. If you have any clues to fix them up, I would appreciate your assistance. Did you get the new version yet?``` Clarification of Question by unlimitedxp-ga on 07 Nov 2004 12:28 PST ```The only significant change that I did was on the linked list classes in order to be able to mix them up with the Term class, but I am still stuck with the two last classes Polynomial and Calculator. As you said before, there must be a mistake in reading the numbers at the final class. I also cannot see how to implement the stack class to contain the operands of the calculator and I also don?t know how to implement the linked list at the calculator class. If you can figure these problems out that would means that we are getting close to finish this project.``` Request for Question Clarification by endo-ga on 07 Nov 2004 12:35 PST ```Hi, I downloaded the new files, but it's not a good idea for us to work on them at the same time. Keep on coding the new version, and tell me when you get stuck and I'll try and help you out. In the meantime, I'll try and fix the old version. Thanks. endo``` Clarification of Question by unlimitedxp-ga on 07 Nov 2004 12:59 PST ```Dear Endo Please enter the numbers that you need to compute: 4 x^3 + 5 x^6 +4*x^4 4 4 +3*x^3 +4*x^4 3 3 Exception in thread "main" java.lang.ClassCastException at Polynomial.add(Polynomial.java:88) at Calculator.main(Calculator.java:136) As you can see, I am still having almost the same problems with the new version than I did with the old one. If you can help me to fix this problem and the questions that I already mention before. I think we will be so close to solve it by today.Thank you``` Request for Question Clarification by endo-ga on 07 Nov 2004 13:07 PST ```Hi, Are you referring to new code you just uploaded? Thanks. endo``` Clarification of Question by unlimitedxp-ga on 07 Nov 2004 13:15 PST ```Dear endo Yes I am, I am referring to the new code. Thank you``` Request for Question Clarification by endo-ga on 07 Nov 2004 13:31 PST ```Hi, I uploaded Calculator.java again. It works for addition. You need to respect the syntax exactly though. E.g. the position of the spaces. Try: 1 x^2 + 3 x^5 + 5 x^2 Thanks. endo``` Clarification of Question by unlimitedxp-ga on 07 Nov 2004 13:39 PST ```Dear Endo Can you upload the calculator class again?, because I have missed the last one that you already uploaded. Sorry and Thank you ahh and please tell me the location of the new one.``` Request for Question Clarification by endo-ga on 07 Nov 2004 13:57 PST ```Hi, I uploaded it again. It's in newjavaclasses. Thanks. endo``` Clarification of Question by unlimitedxp-ga on 07 Nov 2004 14:03 PST ```Dear Endo You are absolutely right, I could perform the addition operation. We are almost done!!!!! I am so happy!! :) Thank you``` Request for Question Clarification by endo-ga on 07 Nov 2004 14:29 PST ```Hi, That's good. Let me know if you get stuck again. Thanks. endo``` Clarification of Question by unlimitedxp-ga on 07 Nov 2004 15:38 PST ```Dear Endo I am still working on Polynomial class with the multiplication and substraction methods. Do you have something new? Thank you``` Request for Question Clarification by endo-ga on 07 Nov 2004 15:41 PST ```Hi, Multiplication should almost work. Upload any changes you made, and I'll have a look at multiplication. Thanks. endo``` Clarification of Question by unlimitedxp-ga on 07 Nov 2004 16:00 PST ```Please enter the numbers that you need to compute: 1 x^2 * 3 x^5 * 5 x^2 Exception in thread "main" java.lang.ClassCastException at Polynomial.multiply(Polynomial.java:113) at Calculator.main(Calculator.java:183) There is a mistake at line 113 from Polynomial class, but I did an if statment to make sure that line does not give me an empty value. It looks like it is working fine.Then I looked up at the main calculator class to see if I need an extra code in there, but I did not see anything wrong. Do you know what is causing that exception?.Meanwhile, I will keep working on it``` Clarification of Question by unlimitedxp-ga on 07 Nov 2004 16:07 PST ```I also did some changes in the main, but the multiplication is still adding instead of multiplying. I will also upload the main class and one input and ouput. Please enter the numbers that you need to compute: 4 x^2 * 3 x^5 * 5 x^2 Answer +9*x^2 +3*x^5``` Request for Question Clarification by endo-ga on 07 Nov 2004 17:11 PST ```Hi, I've uploaded new files. Multiplication works now. Thanks. endo``` Clarification of Question by unlimitedxp-ga on 07 Nov 2004 17:40 PST `r` Clarification of Question by unlimitedxp-ga on 07 Nov 2004 17:43 PST ```Dear endo the multiplitacion is working now!!!! For the substraction must be the same as the addition. I mean do i have to create a new substraction method in the polynomial class, or I can still substracting with the add method. In order to be able to read the substraction method, Can I do the same thing as you did with the multiplication, just changing instead of stacky = stacky.multiply(stacky); a stacky = stacky.add(stacky); for the substracting operation. What do you recommend me to do?``` Clarification of Question by unlimitedxp-ga on 07 Nov 2004 17:50 PST ```Dear Endo Please help to finish the last requierements of this assignment endo, because I have not slept that well, so I am having problems to concentrate and trying to figure it out the last part. I would add an extra price list.Thank you``` Request for Question Clarification by endo-ga on 07 Nov 2004 17:50 PST ```Hi, For subtraction I recommend you try and do the same thing as multiplication. Let me know if you get stuck. I'm going to have to sleep soon. Thanks. endo``` Request for Question Clarification by endo-ga on 07 Nov 2004 17:51 PST ```Hi, What's left? You want me to finish with subtraction? If you're really happy with the answer you can tip me, once I've posted something in the answer box. Thanks. endo``` Clarification of Question by unlimitedxp-ga on 07 Nov 2004 17:55 PST ```Is this the output is supposed to give me for substraction? Please enter the numbers that you need to compute: 4 x^2 - 3 x^5 - 5 x^2 Answer +0*x^4 +0*x^6 +0*x^8 +0*x^9 +0*x^11 +0*x^12 +0*x^14 +0*x^17 +0*x^20``` Request for Question Clarification by endo-ga on 07 Nov 2004 18:01 PST ```Hi, No, that's incorrect. For: 4 x^2 - 3 x^5 - 5 x^2 You should get: -1 x^2 - 3 x^5 Thanks. endo``` Clarification of Question by unlimitedxp-ga on 07 Nov 2004 18:16 PST ```I think that I am getting close, this is the answer that is giving me the substract method. Please enter the numbers that you need to compute: 4 x^2 - 3 x^5 - 5 x^2 Answer +7*x^2 +-7*x^5 What could be gone wrong?``` Clarification of Question by unlimitedxp-ga on 07 Nov 2004 18:19 PST ```Please enter the numbers that you need to compute: 4 x^2 - 3 x^5 - 5 x^2 Answer +0*x^2 +0*x^5 This is my next output,This one is not computing exactly the operations.``` Request for Question Clarification by endo-ga on 07 Nov 2004 18:21 PST ```Hi, That's still wrong. If you try and do it the same way as the multiplication, it should work. Thanks. endo``` Clarification of Question by unlimitedxp-ga on 07 Nov 2004 18:26 PST ```Dear endo I am going to upload the substraction method, to see if you could see it and tell me what is wrong with it, before you go to bed. Thank you``` Clarification of Question by unlimitedxp-ga on 07 Nov 2004 18:30 PST `Did you get them yet?` Request for Question Clarification by endo-ga on 07 Nov 2004 18:31 PST ```Hi, That's ok, I'll get back to you soon and post that as an answer, ok? Thanks. endo``` Clarification of Question by unlimitedxp-ga on 07 Nov 2004 18:36 PST ```Dear endo sure thats fine!!! Thanks a lot```
 Subject: Re: Equation code, need help Answered By: endo-ga on 07 Nov 2004 19:26 PST Rated:
 ```Hi, I figured out why addition was working, it's because you do the addition automatically in insertTerm. So I did subtraction as a mix of addition and multiplication and added a new function called insertNegTerm. I also had to rewrite multiplication because it somehow got lost in the uploading/downloading. I uploaded the new versions of Calculator and Polynomial. It works now for addition, multiplication and subtraction. If you need any more help, please let me know. But I'll be going to sleep soon. Thanks. endo``` Request for Answer Clarification by unlimitedxp-ga on 07 Nov 2004 19:48 PST ```Just one more clarification, before you go to bed. "c" should combine the terms of the polynomial at the top of the stack. Does that means that I must enter one polynomial equation then a c and after that I will enter the last polynomial equation to add both and get a single result.``` Clarification of Answer by endo-ga on 07 Nov 2004 19:59 PST ```Hi, You already combine the terms of the polynomial automatically when you do insertTerm. It means that if the polynomial is: 5 x^2 + 3 x^2, you rewrite it as 8 x^2. Thanks. endo``` Clarification of Answer by endo-ga on 08 Nov 2004 05:20 PST ```Thank you for the great rating, very generous tip and kind comment! Good luck with your work!```
 unlimitedxp-ga rated this answer: and gave an additional tip of: \$50.00 ```He is really helpful, he was always on time to respond my questions with a properly feedback. As you well noted, there were a lot of communication between us during this assignment. I will definetely will work with him again. I really appreaciate what he did for me. I was really having troubles to try to figure it out this problem, because I was in a hurry and I lost a lot of time trying to reach someone at the work. Thanks a lot Endo```

 ```Oops ... I have just whizzed my through this little exercise and I was about to post the solution when I noticed that you require it to be emailed to you ... Sorry but that is strictly against the GA Rules!```
 ```As endo-ga is now on the case, I will step aside because I am sure that he will sort it out for you. Good luck!```