Additions to GREL:

* Factorial function allowing variable steps
* GreatestCommonDenominator function
* LeastCommonMultiple function
* Multinomial function
* Quotient function

git-svn-id: http://google-refine.googlecode.com/svn/trunk@1910 7d457c2a-affb-35e4-300a-418c747d4874

main/src/com/google/refine/expr/functions/math/Combin.java

@@ -60,9 +60,9 @@ public class Combin implements Function {
             throw new IllegalArgumentException ("the number of elements, n, should be larger than the number of combinations, k");
         if (n < 1)
             throw new IllegalArgumentException ("the number of elements, n, cannot be less than 1");
-        int nFact = Fact.factorial(n);
+        int nFact = FactN.factorial(n, 1);
-        int rFact = Fact.factorial(k);
+        int rFact = FactN.factorial(k, 1);
-        int nminusrFact = Fact.factorial(n - k);
+        int nminusrFact = FactN.factorial(n - k, 1);
         return nFact / (rFact * nminusrFact);
     }
 

main/src/com/google/refine/expr/functions/math/Fact.java

@@ -46,22 +46,11 @@ public class Fact implements Function {
 
     public Object call(Properties bindings, Object[] args) {
         if (args.length == 1 && args[0] != null && args[0] instanceof Number) {
-            return Fact.factorial(((Number) args[0]).intValue());
+            return FactN.factorial(((Number) args[0]).intValue(), 1);
         }
         return new EvalError(ControlFunctionRegistry.getFunctionName(this) + " expects a number");
     }
 
-    /*
-     * Calculates the factorial of an integer, i.
-     * Returns 1 for zero and negative integers.
-     */
-    public static int factorial(int i){
-        if(i <= 1)
-            return 1;
-        else
-            return i * Fact.factorial(i - 1);
-    }
-
     public void write(JSONWriter writer, Properties options)
         throws JSONException {
 

main/src/com/google/refine/expr/functions/math/FactN.java

@@ -0,0 +1,80 @@
+/*
+
+Copyright 2010, Google Inc.
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+    * Redistributions of source code must retain the above copyright
+notice, this list of conditions and the following disclaimer.
+    * Redistributions in binary form must reproduce the above
+copyright notice, this list of conditions and the following disclaimer
+in the documentation and/or other materials provided with the
+distribution.
+    * Neither the name of Google Inc. nor the names of its
+contributors may be used to endorse or promote products derived from
+this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+*/
+
+package com.google.refine.expr.functions.math;
+
+import java.util.Properties;
+
+import org.json.JSONException;
+import org.json.JSONWriter;
+
+import com.google.refine.expr.EvalError;
+import com.google.refine.grel.ControlFunctionRegistry;
+import com.google.refine.grel.Function;
+
+public class FactN implements Function {
+
+    public Object call(Properties bindings, Object[] args) {
+        if (args.length != 2)
+            return new EvalError(ControlFunctionRegistry.getFunctionName(this) + " expects two numbers");
+        if(args[0] == null || !(args[0] instanceof Number))
+            return new EvalError(ControlFunctionRegistry.getFunctionName(this) + " expects the first parameter to be a number");
+        if(args[1] == null && !(args[1] instanceof Number))
+            return new EvalError(ControlFunctionRegistry.getFunctionName(this) + " expects the second parameter to be a number");
+
+        return FactN.factorial(((Number) args[0]).intValue(), ((Number) args[1]).intValue());
+
+    }
+
+    /*
+     * Calculates the factorial of an integer, i, for a decreasing step of n.
+     * e.g. A double factorial would have a step of 2.
+     * Returns 1 for zero and negative integers.
+     */
+    public static int factorial(int i, int step){
+        if(i <= 1)
+            return 1;
+        else
+            return i * FactN.factorial(i - step, step);
+    }
+
+    public void write(JSONWriter writer, Properties options)
+        throws JSONException {
+
+        writer.object();
+        writer.key("description"); writer.value("Returns the factorial of a number");
+        writer.key("params"); writer.value("number i");
+        writer.key("returns"); writer.value("number");
+        writer.endObject();
+    }
+}

main/src/com/google/refine/expr/functions/math/GreatestCommonDenominator.java

@@ -0,0 +1,68 @@
+/*
+
+Copyright 2010, Google Inc.
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+    * Redistributions of source code must retain the above copyright
+notice, this list of conditions and the following disclaimer.
+    * Redistributions in binary form must reproduce the above
+copyright notice, this list of conditions and the following disclaimer
+in the documentation and/or other materials provided with the
+distribution.
+    * Neither the name of Google Inc. nor the names of its
+contributors may be used to endorse or promote products derived from
+this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+*/
+
+package com.google.refine.expr.functions.math;
+
+import java.util.Properties;
+
+import org.json.JSONException;
+import org.json.JSONWriter;
+
+import com.google.refine.expr.EvalError;
+import com.google.refine.grel.ControlFunctionRegistry;
+import com.google.refine.grel.Function;
+
+public class GreatestCommonDenominator implements Function {
+
+    public Object call(Properties bindings, Object[] args) {
+        if (args.length == 2 && args[0] != null && args[0] instanceof Number
+                && args[1] != null && args[1] instanceof Number) {
+            return GreatestCommonDenominator.GCD(((Number) args[0]).doubleValue(), ((Number) args[1]).doubleValue());
+        }
+        return new EvalError(ControlFunctionRegistry.getFunctionName(this) + " expects two numbers");
+    }
+
+    public static double GCD(double a, double b){
+        return b == 0 ? a : GCD(b, a % b);
+    }
+
+    public void write(JSONWriter writer, Properties options)
+        throws JSONException {
+
+        writer.object();
+        writer.key("description"); writer.value("Returns the greatest common denominator of the two numbers");
+        writer.key("params"); writer.value("number d, number e");
+        writer.key("returns"); writer.value("number");
+        writer.endObject();
+    }
+}

main/src/com/google/refine/expr/functions/math/LeastCommonMultiple.java

@@ -0,0 +1,79 @@
+/*
+
+Copyright 2010, Google Inc.
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+    * Redistributions of source code must retain the above copyright
+notice, this list of conditions and the following disclaimer.
+    * Redistributions in binary form must reproduce the above
+copyright notice, this list of conditions and the following disclaimer
+in the documentation and/or other materials provided with the
+distribution.
+    * Neither the name of Google Inc. nor the names of its
+contributors may be used to endorse or promote products derived from
+this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+*/
+
+package com.google.refine.expr.functions.math;
+
+import java.util.Properties;
+
+import org.json.JSONException;
+import org.json.JSONWriter;
+
+import com.google.refine.expr.EvalError;
+import com.google.refine.grel.ControlFunctionRegistry;
+import com.google.refine.grel.Function;
+
+public class LeastCommonMultiple implements Function {
+
+    public Object call(Properties bindings, Object[] args) {
+        if (args.length == 2
+                && args[0] != null && args[0] instanceof Number
+                && args[1] != null && args[1] instanceof Number) {
+            return LeastCommonMultiple.LCM(((Number) args[0]).doubleValue(), ((Number) args[1]).doubleValue());
+        }
+        return new EvalError(ControlFunctionRegistry.getFunctionName(this) + " expects two numbers");
+    }
+
+    public static double LCM(double a, double b){
+        double largerValue = a;
+        double smallerValue = b;
+        if(b > a){
+            largerValue = b;
+            smallerValue = a;
+        }
+        for(int i = 1; i <= largerValue; i++){
+            if((largerValue*i) % smallerValue == 0)
+                return largerValue * i;
+        }
+        return largerValue * smallerValue;
+    }
+
+    public void write(JSONWriter writer, Properties options)
+        throws JSONException {
+
+        writer.object();
+        writer.key("description"); writer.value("Returns the greatest common denominator of the two numbers");
+        writer.key("params"); writer.value("number d, number e");
+        writer.key("returns"); writer.value("number");
+        writer.endObject();
+    }
+}

main/src/com/google/refine/expr/functions/math/Multinomial.java

@@ -0,0 +1,71 @@
+/*
+
+Copyright 2010, Google Inc.
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+    * Redistributions of source code must retain the above copyright
+notice, this list of conditions and the following disclaimer.
+    * Redistributions in binary form must reproduce the above
+copyright notice, this list of conditions and the following disclaimer
+in the documentation and/or other materials provided with the
+distribution.
+    * Neither the name of Google Inc. nor the names of its
+contributors may be used to endorse or promote products derived from
+this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+*/
+
+package com.google.refine.expr.functions.math;
+
+import java.util.Properties;
+
+import org.json.JSONException;
+import org.json.JSONWriter;
+
+import com.google.refine.expr.EvalError;
+import com.google.refine.grel.ControlFunctionRegistry;
+import com.google.refine.grel.Function;
+
+public class Multinomial implements Function {
+
+    public Object call(Properties bindings, Object[] args) {
+        if (args.length < 1)
+            return new EvalError(ControlFunctionRegistry.getFunctionName(this) + " expects one or more numbers");
+        int sum = 0;
+        int product = 1;
+        for(int i = 0; i < args.length; i++){
+            if(args[i] == null && !(args[i] instanceof Number))
+                return new EvalError(ControlFunctionRegistry.getFunctionName(this) + " expects parameter " + (i + 1) + " to be a number");
+            int num = ((Number) args[i]).intValue();
+            sum += num;
+            product *= FactN.factorial(num, 1);
+        }
+        return FactN.factorial(sum, 1) / product;
+    }
+
+    public void write(JSONWriter writer, Properties options)
+        throws JSONException {
+
+        writer.object();
+        writer.key("description"); writer.value("Calculates the multinomial of a series of numbers");
+        writer.key("params"); writer.value("one or more numbers");
+        writer.key("returns"); writer.value("number");
+        writer.endObject();
+    }
+}

main/src/com/google/refine/expr/functions/math/Quotient.java

@@ -0,0 +1,64 @@
+/*
+
+Copyright 2010, Google Inc.
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+    * Redistributions of source code must retain the above copyright
+notice, this list of conditions and the following disclaimer.
+    * Redistributions in binary form must reproduce the above
+copyright notice, this list of conditions and the following disclaimer
+in the documentation and/or other materials provided with the
+distribution.
+    * Neither the name of Google Inc. nor the names of its
+contributors may be used to endorse or promote products derived from
+this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+*/
+
+package com.google.refine.expr.functions.math;
+
+import java.util.Properties;
+
+import org.json.JSONException;
+import org.json.JSONWriter;
+
+import com.google.refine.expr.EvalError;
+import com.google.refine.grel.ControlFunctionRegistry;
+import com.google.refine.grel.Function;
+
+public class Quotient implements Function {
+
+    public Object call(Properties bindings, Object[] args) {
+        if (args.length == 2 && args[0] != null && args[0] instanceof Number
+                && args[1] != null && args[1] instanceof Number) {
+            return Math.floor((((Number) args[0]).doubleValue() / ((Number) args[1]).doubleValue()));
+        }
+        return new EvalError(ControlFunctionRegistry.getFunctionName(this) + " expects two numbers");
+    }
+
+    public void write(JSONWriter writer, Properties options)
+        throws JSONException {
+
+        writer.object();
+        writer.key("description"); writer.value("Returns the integer portion of a division");
+        writer.key("params"); writer.value("number numerator, number denominator");
+        writer.key("returns"); writer.value("number");
+        writer.endObject();
+    }
+}

main/src/com/google/refine/grel/ControlFunctionRegistry.java

@@ -72,14 +72,19 @@ import com.google.refine.expr.functions.math.Degrees;
 import com.google.refine.expr.functions.math.Even;
 import com.google.refine.expr.functions.math.Exp;
 import com.google.refine.expr.functions.math.Fact;
+import com.google.refine.expr.functions.math.FactN;
 import com.google.refine.expr.functions.math.Floor;
+import com.google.refine.expr.functions.math.GreatestCommonDenominator;
+import com.google.refine.expr.functions.math.LeastCommonMultiple;
 import com.google.refine.expr.functions.math.Ln;
 import com.google.refine.expr.functions.math.Log;
 import com.google.refine.expr.functions.math.Max;
 import com.google.refine.expr.functions.math.Min;
 import com.google.refine.expr.functions.math.Mod;
+import com.google.refine.expr.functions.math.Multinomial;
 import com.google.refine.expr.functions.math.Odd;
 import com.google.refine.expr.functions.math.Pow;
+import com.google.refine.expr.functions.math.Quotient;
 import com.google.refine.expr.functions.math.Radians;
 import com.google.refine.expr.functions.math.Round;
 import com.google.refine.expr.functions.math.Sin;
@@ -253,9 +258,14 @@ public class ControlFunctionRegistry {
         registerFunction("exp", new Exp());
         registerFunction("sum", new Sum());
         registerFunction("fact", new Fact());
+        registerFunction("factn", new FactN());
         registerFunction("combin", new Combin());
         registerFunction("degrees", new Degrees());
         registerFunction("radians", new Radians());
+        registerFunction("gcd", new GreatestCommonDenominator());
+        registerFunction("lcm", new LeastCommonMultiple());
+        registerFunction("multinomial", new Multinomial());
+        registerFunction("quotient", new Quotient());
 
         registerFunction("and", new And());
         registerFunction("or", new Or());