diff --git a/src/java/org/apache/poi/ss/formula/atp/AnalysisToolPak.java b/src/java/org/apache/poi/ss/formula/atp/AnalysisToolPak.java
index 5274b2348..9139c2e1b 100644
--- a/src/java/org/apache/poi/ss/formula/atp/AnalysisToolPak.java
+++ b/src/java/org/apache/poi/ss/formula/atp/AnalysisToolPak.java
@@ -67,7 +67,7 @@ public final class AnalysisToolPak implements UDFFinder {
r(m, "BESSELJ", null);
r(m, "BESSELK", null);
r(m, "BESSELY", null);
- r(m, "BIN2DEC", null);
+ r(m, "BIN2DEC", Bin2Dec.instance);
r(m, "BIN2HEX", null);
r(m, "BIN2OCT", null);
r(m, "COMPLEX", Complex.instance);
diff --git a/src/java/org/apache/poi/ss/formula/functions/Bin2Dec.java b/src/java/org/apache/poi/ss/formula/functions/Bin2Dec.java
new file mode 100644
index 000000000..c84229d70
--- /dev/null
+++ b/src/java/org/apache/poi/ss/formula/functions/Bin2Dec.java
@@ -0,0 +1,95 @@
+package org.apache.poi.ss.formula.functions;
+
+import org.apache.poi.ss.formula.OperationEvaluationContext;
+import org.apache.poi.ss.formula.eval.*;
+
+/**
+ * Implementation for Excel Bin2Dec() function.
+ *
+ * Syntax:
Bin2Dec (number)
+ *
+ * Converts a binary number to decimal.
+ *
+ * Number is the binary number you want to convert. Number cannot contain more than 10 characters (10 bits).
+ * The most significant bit of number is the sign bit. The remaining 9 bits are magnitude bits.
+ * Negative numbers are represented using two's-complement notation.
+ *
+ * Remark
+ * If number is not a valid binary number, or if number contains more than 10 characters (10 bits),
+ * BIN2DEC returns the #NUM! error value.
+ *
+ * @author cedric dot walter @ gmail dot com
+ */
+public class Bin2Dec extends Fixed1ArgFunction implements FreeRefFunction {
+
+ public static final FreeRefFunction instance = new Bin2Dec();
+
+ public ValueEval evaluate(int srcRowIndex, int srcColumnIndex, ValueEval numberVE) {
+ String number = OperandResolver.coerceValueToString(numberVE);
+ if (number.length() > 10) {
+ return ErrorEval.NUM_ERROR;
+ }
+
+ String unsigned;
+
+ //If the leftmost bit is 0 -- number is positive.
+ boolean isPositive;
+ if (number.length() < 10) {
+ unsigned = number;
+ isPositive = true;
+ } else {
+ unsigned = number.substring(1);
+ isPositive = number.startsWith("0");
+ }
+
+ String value;
+ int sum;
+ if (isPositive) {
+ //bit9*2^8 + bit8*2^7 + bit7*2^6 + bit6*2^5 + bit5*2^4+ bit3*2^2+ bit2*2^1+ bit1*2^0
+ sum = getDecimalValue(unsigned);
+ value = String.valueOf(sum);
+ } else {
+ //The leftmost bit is 1 -- this is negative number
+ //Inverse bits [1-9]
+ String inverted = toggleBits(unsigned);
+ // Calculate decimal number
+ sum = getDecimalValue(inverted);
+
+ //Add 1 to obtained number
+ sum++;
+
+ value = "-" + String.valueOf(sum);
+ }
+
+ return new NumberEval(Long.parseLong(value));
+ }
+
+ private int getDecimalValue(String unsigned) {
+ int sum = 0;
+ int numBits = unsigned.length();
+ int power = numBits - 1;
+
+ for (int i = 0; i < numBits; i++) {
+ int bit = Integer.parseInt(unsigned.substring(i, i + 1));
+ int term = (int) (bit * Math.pow(2, power));
+ sum += term;
+ power--;
+ }
+ return sum;
+ }
+
+ private static String toggleBits(String s) {
+ long i = Long.parseLong(s, 2);
+ long i2 = i ^ ((1L << s.length()) - 1);
+ String s2 = Long.toBinaryString(i2);
+ while (s2.length() < s.length()) s2 = '0' + s2;
+ return s2;
+ }
+
+ public ValueEval evaluate(ValueEval[] args, OperationEvaluationContext ec) {
+ if (args.length != 1) {
+ return ErrorEval.VALUE_INVALID;
+ }
+ return evaluate(ec.getRowIndex(), ec.getColumnIndex(), args[0]);
+ }
+}
diff --git a/test-data/spreadsheet/FormulaEvalTestData.xls b/test-data/spreadsheet/FormulaEvalTestData.xls
index 672febdf1..3b3f724b7 100644
Binary files a/test-data/spreadsheet/FormulaEvalTestData.xls and b/test-data/spreadsheet/FormulaEvalTestData.xls differ