variableValues);
+
+}
diff --git a/core/src/net/sf/openrocket/util/exp4j/CommandlineInterpreter.java b/core/src/net/sf/openrocket/util/exp4j/CommandlineInterpreter.java
new file mode 100644
index 000000000..443545f0f
--- /dev/null
+++ b/core/src/net/sf/openrocket/util/exp4j/CommandlineInterpreter.java
@@ -0,0 +1,58 @@
+/*
+ Copyright 2011 frank asseg
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+
+ */
+package net.sf.openrocket.util.exp4j;
+/**
+ * Simple commandline interpreter for mathematical expressions the interpreter
+ * takes a mathematical expressions as a {@link String} argument, evaluates it
+ * and prints out the result.
+ *
+ *
+ *
+ * java de.congrace.exp4j.CommandlineInterpreter "2 * log(2.2223) - ((2-3.221) * 14.232^2)"
+ * > 248.91042049521056
+ *
+ *
+ * @author fas@congrace.de
+ *
+ */
+public class CommandlineInterpreter {
+ private static void calculateExpression(String string) {
+ try {
+ final PostfixExpression pe = PostfixExpression.fromInfix(string);
+ System.out.println(pe.calculate());
+ } catch (UnparsableExpressionException e) {
+ e.printStackTrace();
+ } catch (UnknownFunctionException e) {
+ e.printStackTrace();
+ }
+ }
+
+ public static void main(String[] args) {
+ if (args.length != 1) {
+ printUsage();
+ } else {
+ calculateExpression(args[0]);
+ }
+ }
+
+ private static void printUsage() {
+ final StringBuilder usage = new StringBuilder();
+ usage.append("Commandline Expression Parser\n\n").append("Example: ").append("\n").append("java -jar exp4j.jar \"2.12 * log(23) * (12 - 4)\"\n\n")
+ .append("written by fas@congrace.de");
+ System.err.println(usage.toString());
+ }
+}
diff --git a/core/src/net/sf/openrocket/util/exp4j/CustomFunction.java b/core/src/net/sf/openrocket/util/exp4j/CustomFunction.java
new file mode 100644
index 000000000..8a437af24
--- /dev/null
+++ b/core/src/net/sf/openrocket/util/exp4j/CustomFunction.java
@@ -0,0 +1,84 @@
+package net.sf.openrocket.util.exp4j;
+import java.util.Map;
+import java.util.Stack;
+
+import net.sf.openrocket.util.exp4j.FunctionToken.Function;
+
+/**
+ * this classed is used to create custom functions for exp4j
+ *
+ * Example
+ * {@code
+ * CustomFunction fooFunc = new CustomFunction("foo") {
+ * public double applyFunction(double value) {
+ * return value*Math.E;
+ * }
+ * };
+ * double varX=12d;
+ * Calculable calc = new ExpressionBuilder("foo(x)").withCustomFunction(fooFunc).withVariable("x",varX).build();
+ * assertTrue(calc.calculate() == Math.E * varX);
+ * }
+ * The default way to create a new instance of {@link PostfixExpression} is by
+ * using the static factory method fromInfix()
+ *
+ * @author fas@congrace.de
+ */
+public final class PostfixExpression extends AbstractExpression implements Calculable {
+ /**
+ * Factory method for creating {@link PostfixExpression}s from human
+ * readable infix expressions
+ *
+ * @param expression
+ * the infix expression to be used
+ * @return an equivalent {@link PostfixExpression}
+ * @throws UnparsableExpressionException
+ * if the expression was invalid
+ * @throws UnknownFunctionException
+ * if an unknown function has been used
+ * @deprecated please use {@link ExpressionBuilder} API
+ */
+ @Deprecated
+ public static PostfixExpression fromInfix(String expression) throws UnparsableExpressionException, UnknownFunctionException {
+ return fromInfix(expression, null);
+ }
+
+ /**
+ * Factory method for creating {@link PostfixExpression}s from human
+ * readable infix expressions
+ *
+ * @param expression
+ * the infix expression to be used
+ * @param customFunctions
+ * the CustomFunction implementations used
+ * @return an equivalent {@link PostfixExpression}
+ * @throws UnparsableExpressionException
+ * if the expression was invalid
+ * @throws UnknownFunctionException
+ * if an unknown function has been used
+ * @deprecated please use {@link ExpressionBuilder}
+ */
+ @Deprecated
+ public static PostfixExpression fromInfix(String expression, Set customFunctions) throws UnparsableExpressionException,
+ UnknownFunctionException {
+ String[] variables = null;
+ int posStart, posEnd;
+ if ((posStart = expression.indexOf('=')) > 0) {
+ String functionDef = expression.substring(0, posStart);
+ expression = expression.substring(posStart + 1);
+ if ((posStart = functionDef.indexOf('(')) > 0 && (posEnd = functionDef.indexOf(')')) > 0) {
+ variables = functionDef.substring(posStart + 1, posEnd).split(",");
+ }
+ }
+ return new PostfixExpression(InfixTranslator.toPostfixExpression(expression, variables, customFunctions), variables, customFunctions);
+ }
+
+ private final Map variableValues = new HashMap();
+
+ /**
+ * Construct a new simple {@link PostfixExpression}
+ *
+ * @param expression
+ * the postfix expression to be calculated
+ * @param variableNames
+ * the variable names in the expression
+ * @param customFunctions
+ * the CustomFunction implementations used
+ * @throws UnparsableExpressionException
+ * when expression is invalid
+ * @throws UnknownFunctionException
+ * when an unknown function has been used
+ */
+ private PostfixExpression(String expression, String[] variableNames, Set customFunctions) throws UnparsableExpressionException,
+ UnknownFunctionException {
+ super(expression, new Tokenizer(variableNames, customFunctions).tokenize(expression), variableNames);
+ }
+
+ /**
+ * delegate the calculation of a simple expression without variables
+ *
+ * @return the result
+ */
+ public double calculate() {
+ return calculate(null);
+ }
+
+ /**
+ * calculate the result of the expression and substitute the variables by
+ * their values beforehand
+ *
+ * @param values
+ * the variable values to be substituted
+ * @return the result of the calculation
+ * @throws IllegalArgumentException
+ * if the variables are invalid
+ */
+ public double calculate(double... values) throws IllegalArgumentException {
+ if (getVariableNames() == null && values != null) {
+ throw new IllegalArgumentException("there are no variables to set values");
+ } else if (getVariableNames() != null && values == null && variableValues.isEmpty()) {
+ throw new IllegalAccessError("variable values have to be set");
+ } else if (values != null && values.length != getVariableNames().length) {
+ throw new IllegalArgumentException("The are an unequal number of variables and arguments");
+ }
+ int i = 0;
+ if (getVariableNames() != null && values != null) {
+ for (double val : values) {
+ variableValues.put(getVariableNames()[i++], val);
+ }
+ }
+ final Stack stack = new Stack();
+ for (final Token t : getTokens()) {
+ ((CalculationToken) t).mutateStackForCalculation(stack, variableValues);
+ }
+ return stack.pop();
+ }
+
+ public void setVariable(String name, double value) {
+ variableValues.put(name, value);
+ }
+}
diff --git a/core/src/net/sf/openrocket/util/exp4j/Token.java b/core/src/net/sf/openrocket/util/exp4j/Token.java
new file mode 100644
index 000000000..3e0024cce
--- /dev/null
+++ b/core/src/net/sf/openrocket/util/exp4j/Token.java
@@ -0,0 +1,50 @@
+/*
+ Copyright 2011 frank asseg
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+
+ */
+package net.sf.openrocket.util.exp4j;
+
+import java.util.Stack;
+
+/**
+ * Superclass for tokenized Strings
+ *
+ * @author fas@congrace.de
+ */
+abstract class Token {
+ private final String value;
+
+ /**
+ * construct a new {@link Token}
+ *
+ * @param value
+ * the value of the {@link Token}
+ */
+ Token(String value) {
+ super();
+ this.value = value;
+ }
+
+ /**
+ * get the value (String representation) of the token
+ *
+ * @return the value
+ */
+ String getValue() {
+ return value;
+ }
+
+ abstract void mutateStackForInfixTranslation(Stack operatorStack, StringBuilder output);
+}
diff --git a/core/src/net/sf/openrocket/util/exp4j/Tokenizer.java b/core/src/net/sf/openrocket/util/exp4j/Tokenizer.java
new file mode 100644
index 000000000..8290de35d
--- /dev/null
+++ b/core/src/net/sf/openrocket/util/exp4j/Tokenizer.java
@@ -0,0 +1,219 @@
+/*
+ Copyright 2011 frank asseg
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+
+ */
+package net.sf.openrocket.util.exp4j;
+
+import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+
+import net.sf.openrocket.util.exp4j.FunctionToken.Function;
+
+/**
+ * Class for tokenizing mathematical expressions by breaking an expression up
+ * into multiple different {@link Token}s
+ *
+ * @author fas@congrace.de
+ */
+class Tokenizer {
+ private String[] variableNames;
+ private final Set functionNames = new HashSet();
+ private final Set customFunctions;
+
+ {
+ functionNames.add("abs");
+ functionNames.add("acos");
+ functionNames.add("asin");
+ functionNames.add("atan");
+ functionNames.add("cbrt");
+ functionNames.add("ceil");
+ functionNames.add("cos");
+ functionNames.add("cosh");
+ functionNames.add("exp");
+ functionNames.add("expm1");
+ functionNames.add("floor");
+ functionNames.add("log");
+ functionNames.add("sin");
+ functionNames.add("sinh");
+ functionNames.add("sqrt");
+ functionNames.add("tan");
+ functionNames.add("tanh");
+ }
+
+ Tokenizer() {
+ super();
+ customFunctions = null;
+ }
+
+ /**
+ * construct a new Tokenizer that recognizes variable names
+ *
+ * @param variableNames
+ * the variable names in the expression
+ * @throws IllegalArgumentException
+ * if a variable has the name as a function
+ * @param customFunctions
+ * the CustomFunction implementations used if the variableNames
+ * are not valid
+ */
+ Tokenizer(String[] variableNames, Set customFunctions) throws IllegalArgumentException {
+ super();
+ this.variableNames = variableNames;
+ if (variableNames != null) {
+ for (String varName : variableNames) {
+ if (functionNames.contains(varName.toLowerCase())) {
+ throw new IllegalArgumentException("Variable '" + varName + "' can not have the same name as a function");
+ }
+ }
+ }
+ this.customFunctions = customFunctions;
+ }
+
+ private Token getCustomFunctionToken(String name) throws UnknownFunctionException {
+ for (CustomFunction func : customFunctions) {
+ if (func.getValue().equals(name)) {
+ return func;
+ }
+ }
+ throw new UnknownFunctionException(name);
+ }
+
+ private boolean isCustomFunction(String name) {
+ if (customFunctions == null) {
+ return false;
+ }
+ for (CustomFunction func : customFunctions) {
+ if (func.getValue().equals(name)) {
+ return true;
+ }
+ }
+ return false;
+ }
+
+ /**
+ * check if a char is part of a number
+ *
+ * @param c
+ * the char to be checked
+ * @return true if the char is part of a number
+ */
+ private boolean isDigit(char c) {
+ return Character.isDigit(c) || c == '.';
+ }
+
+ private boolean isFunction(String name) {
+ for (Function fn : Function.values()) {
+ if (fn.name().equals(name.toUpperCase())) {
+ return true;
+ }
+ }
+ return false;
+ }
+
+ /**
+ * check if a String is a variable name
+ *
+ * @param name
+ * the variable name which is checked to be valid the char to be
+ * checked
+ * @return true if the char is a variable name (e.g. x)
+ */
+ private boolean isVariable(String name) {
+ if (variableNames != null) {
+ for (String var : variableNames) {
+ if (name.equals(var)) {
+ return true;
+ }
+ }
+ }
+ return false;
+ }
+
+ /**
+ * tokenize an infix expression by breaking it up into different
+ * {@link Token} that can represent operations,functions,numbers,
+ * parenthesis or variables
+ *
+ * @param infix
+ * the infix expression to be tokenized
+ * @return the {@link Token}s representing the expression
+ * @throws UnparsableExpressionException
+ * when the expression is invalid
+ * @throws UnknownFunctionException
+ * when an unknown function name has been used.
+ */
+ Token[] tokenize(String infix) throws UnparsableExpressionException, UnknownFunctionException {
+ final List tokens = new ArrayList();
+ final char[] chars = infix.toCharArray();
+ // iterate over the chars and fork on different types of input
+ Token lastToken;
+ for (int i = 0; i < chars.length; i++) {
+ char c = chars[i];
+ if (c == ' ')
+ continue;
+ if (isDigit(c)) {
+ final StringBuilder valueBuilder = new StringBuilder(1);
+ // handle the numbers of the expression
+ valueBuilder.append(c);
+ int numberLen = 1;
+ while (chars.length > i + numberLen && isDigit(chars[i + numberLen])) {
+ valueBuilder.append(chars[i + numberLen]);
+ numberLen++;
+ }
+ i += numberLen - 1;
+ lastToken = new NumberToken(valueBuilder.toString());
+ } else if (Character.isLetter(c) || c == '_') {
+ // can be a variable or function
+ final StringBuilder nameBuilder = new StringBuilder();
+ nameBuilder.append(c);
+ int offset = 1;
+ while (chars.length > i + offset && (Character.isLetter(chars[i + offset]) || Character.isDigit(chars[i + offset]) || chars[i + offset] == '_')) {
+ nameBuilder.append(chars[i + offset++]);
+ }
+ String name = nameBuilder.toString();
+ if (this.isVariable(name)) {
+ // a variable
+ i += offset - 1;
+ lastToken = new VariableToken(name);
+ } else if (this.isFunction(name)) {
+ // might be a function
+ i += offset - 1;
+ lastToken = new FunctionToken(name);
+ } else if (this.isCustomFunction(name)) {
+ // a custom function
+ i += offset - 1;
+ lastToken = getCustomFunctionToken(name);
+ } else {
+ // an unknown symbol was encountered
+ throw new UnparsableExpressionException(c, i);
+ }
+ }else if (c == ',') {
+ // a function separator, hopefully
+ lastToken=new FunctionSeparatorToken();
+ } else if (OperatorToken.isOperator(c)) {
+ lastToken = new OperatorToken(String.valueOf(c), OperatorToken.getOperation(c));
+ } else if (c == '(' || c == ')' || c == '[' || c == ']' || c == '{' || c == '}') {
+ lastToken = new ParenthesisToken(String.valueOf(c));
+ } else {
+ // an unknown symbol was encountered
+ throw new UnparsableExpressionException(c, i);
+ }
+ tokens.add(lastToken);
+ }
+ return tokens.toArray(new Token[tokens.size()]);
+ }
+}
diff --git a/core/src/net/sf/openrocket/util/exp4j/UnknownFunctionException.java b/core/src/net/sf/openrocket/util/exp4j/UnknownFunctionException.java
new file mode 100644
index 000000000..a7a6beb9a
--- /dev/null
+++ b/core/src/net/sf/openrocket/util/exp4j/UnknownFunctionException.java
@@ -0,0 +1,37 @@
+/*
+ Copyright 2011 frank asseg
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+
+ */
+package net.sf.openrocket.util.exp4j;
+
+/**
+ * Exception for handling unknown Functions.
+ *
+ * @see FunctionToken
+ * @author fas@congrace.de
+ */
+public class UnknownFunctionException extends Exception {
+ private static final long serialVersionUID = 1L;
+
+ /**
+ * construct a new {@link UnknownFunctionException}
+ *
+ * @param functionName
+ * the function name which could not be found
+ */
+ public UnknownFunctionException(String functionName) {
+ super("Unknown function: " + functionName);
+ }
+}
diff --git a/core/src/net/sf/openrocket/util/exp4j/UnparsableExpressionException.java b/core/src/net/sf/openrocket/util/exp4j/UnparsableExpressionException.java
new file mode 100644
index 000000000..deddcb9b1
--- /dev/null
+++ b/core/src/net/sf/openrocket/util/exp4j/UnparsableExpressionException.java
@@ -0,0 +1,47 @@
+/*
+ Copyright 2011 frank asseg
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+
+ */
+package net.sf.openrocket.util.exp4j;
+
+/**
+ * Exception for invalid expressions
+ *
+ * @author fas@congrace.de
+ */
+public class UnparsableExpressionException extends Exception {
+ private static final long serialVersionUID = 1L;
+
+ /**
+ * construct a new {@link UnparsableExpressionException}
+ *
+ * @param c
+ * the character which could not be parsed
+ * @param pos
+ * the position of the character in the expression
+ */
+ public UnparsableExpressionException(char c, int pos) {
+ super("Unable to parse character at position " + pos + ": '" + String.valueOf(c) + "'");
+ }
+ /**
+ * construct a new {@link UnparsableExpressionException}
+ *
+ * @param msg
+ * the error message
+ */
+ public UnparsableExpressionException(String msg) {
+ super(msg);
+ }
+}
diff --git a/core/src/net/sf/openrocket/util/exp4j/VariableToken.java b/core/src/net/sf/openrocket/util/exp4j/VariableToken.java
new file mode 100644
index 000000000..1d6a336ef
--- /dev/null
+++ b/core/src/net/sf/openrocket/util/exp4j/VariableToken.java
@@ -0,0 +1,48 @@
+/*
+ Copyright 2011 frank asseg
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+
+ */
+package net.sf.openrocket.util.exp4j;
+
+import java.util.Map;
+import java.util.Stack;
+
+/**
+ * A {@link Token} for representing variables
+ *
+ * @author fas
+ */
+class VariableToken extends CalculationToken {
+ /**
+ * construct a new {@link VariableToken}
+ *
+ * @param value
+ * the value of the token
+ */
+ VariableToken(String value) {
+ super(value);
+ }
+
+ @Override
+ void mutateStackForCalculation(Stack stack, Map variableValues) {
+ double value = variableValues.get(this.getValue());
+ stack.push(value);
+ }
+
+ @Override
+ void mutateStackForInfixTranslation(Stack operatorStack, StringBuilder output) {
+ output.append(this.getValue()).append(" ");
+ }
+}