oop.rar_java坐标图

import java.util.*; import java.awt.*; import java.awt.event.*; import javax.swing.*; import javax.swing.event.*; /*A class ListExpression: generate the instance with a string*/ class ListExpression { private Vector expression; //member variable private String string; public ListExpression() {} //default construct /*constructor with a string as a parameter*/ public ListExpression(String str) { this.expression = rightConstruct(getExpr(str)); this.string=getExpr(str); } public Vector getExpression(){ return expression; } public void setExpression(Vector expression){ this.expression=expression; } /* *decide which methods to use according that whether there are brackets with each operator *para: string *return: vector */ Vector rightConstruct(String str){ StringTokenizer spaceToken = new StringTokenizer(str); int len1=spaceToken.countTokens(); String[] strArr=new String[len1]; String subStr=""; for (int i = 0; i <len1 ; i++){ strArr[i]= spaceToken.nextToken(); subStr+=strArr[i]; } Vector right=construct(subStr); int i=1; while (i<len1) { if (strArr[i].equals("+") || strArr[i].equals("-") || strArr[i].equals("*") || strArr[i].equals("/")) { if(!(strArr[i-1].endsWith(")") || strArr[i+1].startsWith("("))) { String cStr=""; i++; while (!(strArr[i].equals("+") || strArr[i].equals("-") || strArr[i].equals("*") || strArr[i].equals("/"))) { cStr+=strArr[i]; if(i<len1-1) i++; else break; } if (!cStr.contains(")")) { right=bracketConstruct(str); break; } } } i++; } return right; } /* *change a string to a string with brackets with each operator and call the construct function *para: string *return: vector */ Vector bracketConstruct(String str){ StringTokenizer spaceToken = new StringTokenizer(str); String noSpaceStr =""; int len1=spaceToken.countTokens(); String[] strArr=new String[len1]; for (int i = 0; i <len1 ; i++) { strArr[i]= spaceToken.nextToken(); noSpaceStr+=strArr[i]; } int i=0; while (i<strArr.length-3) { if (noSpaceStr.charAt(i)=='+' || noSpaceStr.charAt(i)=='-' || noSpaceStr.charAt(i)=='/' || noSpaceStr.charAt(i)=='*') { if (noSpaceStr.charAt(i+2)!=')' && Character.isDigit(noSpaceStr.charAt(i+1))) { for (int k=i+1;k<noSpaceStr.length() ;k++ ) { if (noSpaceStr.charAt(k)=='+' || noSpaceStr.charAt(k)=='-' || noSpaceStr.charAt(i)=='*' || noSpaceStr.charAt(i)=='/') { noSpaceStr=noSpaceStr.substring(0,k)+")"+noSpaceStr.substring(k); break; } } for (int j=i-2;j>=0 ;j-- ) { if (noSpaceStr.charAt(j)=='(') { noSpaceStr=noSpaceStr.substring(0,j)+"("+noSpaceStr.substring(j); break; } } } } i++; } return construct(noSpaceStr); } /* *delete the first brackets and call the function constructVector() to return the required vector *para: string *return: vector */ Vector construct(String noSpaceStr){ String subStr=""; if ((noSpaceStr.charAt(0)=='(')&&(noSpaceStr.charAt(noSpaceStr.length()-1)==')')) { subStr=noSpaceStr.substring(1,noSpaceStr.length()); } return constructVector(subStr); } /* *with a string as the parameter, construct the Polish Notation using vectors *para: string *return: vector */ Vector constructVector(String noSpaceStr) { Vector expr = new Vector(); StringTokenizer strToken = new StringTokenizer(noSpaceStr, "(+*-/)",true); String[] strArr = new String[strToken.countTokens()]; int len=strToken.countTokens(); for (int i = 0; i <len ; i++) strArr[i] = strToken.nextToken(); int i = 0; int left=0; int right=0; while (i < strArr.length) { /*if meet with a "(", add every string until the right ")", we use two variables left and right to control the number of brackets then make a recursive call with the new substring as a parameter*/ if (strArr[i].equals("(")) { left++; i++; String subStr=""; while (true) { if (strArr[i].equals("(")) { left++; } if (strArr[i].equals(")")) { right++; } if (right!=left) { subStr+=strArr[i]; i++; } else break; } expr.add(constructVector(subStr)); } /*if meet with operators, add them to the first position of the vector, else just add them to the vector*/ if (strArr[i].equals("+") || strArr[i].equals("*") || strArr[i].equals("-")|| strArr[i].equals("/")) { expr.add(0, strArr[i]); i++; } else if (strArr[i].startsWith("sin") || strArr[i].startsWith("cos") || strArr[i].startsWith("tan")|| strArr[i].startsWith("cot")) { expr.add(0,strArr[i].substring(0,3)); if(strArr[i].length()>3) expr.add(strArr[i].substring(3)); i++; } else if(strArr[i].equals(")")){ i++; } else{ expr.add(strArr[i]); i++; } } return expr; } /* *to optimize the vector *para: vector *return: vector */ Vector sConstruct(Vector vtr){ Vector nVtr=new Vector(); Vector control=vtr; if(control.size()>2) { String operator=vtr.get(0).toString(); nVtr.add(operator); while (!Character.isDigit((control.get(2).toString()).charAt(0))) { if(control.size()>2) { String operand1=control.get(1).toString(); String operand2=control.get(2).toString(); String opt=((Vector)control.get(2)).get(0).toString(); if (operator.equals(opt)) { nVtr.add(operand1); control=(Vector)((Vector)control.get(2)); } else { nVtr.add(control.get(1)); nVtr.add(control.get(2)); break; } } } } return nVtr; } /* *to evaluate the expression *para: string *return: double */ double evaluate(String str){ Vector evlt=rightConstruct(getExpr(str)); return eVector(evlt); } /* *to evaluate the expression that has varibles *para: ArgumentSet *return: double */ double evaluate(ArgumentSet args){ String str=this.string; Hashtable<String,Double> hash=args.getHash(); Enumeration enu=hash.keys(); while (enu.hasMoreElements()) { String key=(String)enu.nextElement(); if (str.contains(key)) { str=str.replace(key,Double.toString(args.getArgValue(key))); } } return evaluate(str); } double eVector(Vector evlt){ double ret=0; if (evlt.size()==0) { System.out.print(" no result "); } if (evlt.size()==1) { ret=Double.parseDouble(evlt.get(0).toString()); } if(evlt.size()>=2) { String operator=evlt.get(0).toString(); String operand1=evlt.get(1).toString(); String operand2; double opr1,opr2; if (!Character.isDigit(operand1.charAt(0))) { opr1=eVector((Vector)evlt.get(1)); } else { opr1=Double.parseDouble(operand1); } if(evlt.size()==3) { operand2=evlt.get(2).toString(); if (!Character.isDigit(operand2.charAt(0))) { opr2=eVector((Vector)evlt.get(2)); } else { opr2=Double.parseDouble(operand2); } if (operator.equals("+")) { ret=opr1+opr2; } else if (operator.equals("-")) { ret=opr1-opr2; } else if (operator.equals("*")) { ret=opr1*opr2; } else if (operator.equals(