Number formatting

jscl/src/main/java/jscl/JsclMathEngine.java

@@ -9,6 +9,7 @@ import jscl.math.operator.Percent;
 import jscl.math.operator.Rand;
 import jscl.math.operator.matrix.OperatorsRegistry;
 import jscl.text.ParseException;
+import midpcalc.Real;
 import org.solovyev.common.NumberFormatter;
 import org.solovyev.common.math.MathRegistry;
 import org.solovyev.common.msg.MessageRegistry;
@@ -19,6 +20,8 @@ import javax.annotation.Nullable;
 import java.math.BigDecimal;
 import java.util.List;
 
+import static midpcalc.Real.NumberFormat.*;
+
 public class JsclMathEngine implements MathEngine {
 
     public static final AngleUnit DEFAULT_ANGLE_UNITS = AngleUnit.deg;
@@ -38,7 +41,7 @@ public class JsclMathEngine implements MathEngine {
     };
     private char groupingSeparator = GROUPING_SEPARATOR_DEFAULT;
     private boolean roundResult = false;
-    private boolean scienceNotation = false;
+    private int numberFormat = FSE_NONE;
     private int precision = 5;
     private boolean useGroupingSeparator = false;
     @Nonnull
@@ -166,11 +169,17 @@ public class JsclMathEngine implements MathEngine {
         }
         final NumberFormatter nf = numberFormatter.get();
         nf.setGroupingSeparator(useGroupingSeparator ? groupingSeparator : NumberFormatter.NO_GROUPING);
-        nf.setPrecision(roundResult ? precision : NumberFormatter.DEFAULT_PRECISION);
+        nf.setPrecision(roundResult ? precision : NumberFormatter.NO_ROUNDING);
-        if (scienceNotation) {
+        switch (numberFormat) {
+            case Real.NumberFormat.FSE_ENG:
                 nf.useEngineeringFormat(NumberFormatter.DEFAULT_MAGNITUDE);
-        } else {
+                break;
+            case FSE_SCI:
+                nf.useScientificFormat(NumberFormatter.DEFAULT_MAGNITUDE);
+                break;
+            default:
                 nf.useSimpleFormat();
+                break;
         }
         return nf.format(value, nb.radix).toString();
     }
@@ -307,7 +316,14 @@ public class JsclMathEngine implements MathEngine {
     }
 
     public void setScienceNotation(boolean scienceNotation) {
-        this.scienceNotation = scienceNotation;
+        setNumberFormat(scienceNotation ? FSE_SCI : FSE_NONE);
+    }
+
+    public void setNumberFormat(int numberFormat) {
+        if (numberFormat != FSE_SCI && numberFormat != FSE_ENG && numberFormat != FSE_NONE) {
+            throw new IllegalArgumentException("Unsupported format: " + numberFormat);
+        }
+        this.numberFormat = numberFormat;
     }
 
     public char getGroupingSeparator() {

jscl/src/main/java/org/solovyev/common/NumberFormatter.java

@@ -5,21 +5,28 @@ import midpcalc.Real;
 import javax.annotation.Nonnull;
 import java.math.BigDecimal;
 
+import static java.lang.Math.pow;
 import static midpcalc.Real.NumberFormat.*;
 
 public class NumberFormatter {
 
     public static final int NO_GROUPING = 0;
-    public static final int DEFAULT_PRECISION = 16;
+    public static final int NO_ROUNDING = -1;
     public static final int DEFAULT_MAGNITUDE = 5;
+    public static final int MAX_PRECISION = 16;
 
     private final Real.NumberFormat numberFormat = new Real.NumberFormat();
     private final Real real = new Real();
     private int format = FSE_NONE;
     private int simpleFormatMagnitude = DEFAULT_MAGNITUDE;
-    private int precision = DEFAULT_PRECISION;
+    private int precision = MAX_PRECISION;
     private char groupingSeparator;
 
+    public void useScientificFormat(int simpleFormatMagnitude) {
+        this.format = FSE_SCI;
+        this.simpleFormatMagnitude = simpleFormatMagnitude;
+    }
+
     public void useEngineeringFormat(int simpleFormatMagnitude) {
         this.format = FSE_ENG;
         this.simpleFormatMagnitude = simpleFormatMagnitude;
@@ -49,19 +56,27 @@ public class NumberFormatter {
             throw new IllegalArgumentException("Unsupported radix: " + radix);
         }
         double absValue = Math.abs(value);
-        final boolean dec = radix == 10;
+        final boolean simpleFormat = useSimpleFormat(radix, absValue);
-        final boolean fixedFormat = !dec || format == FSE_NONE || Math.pow(10, -simpleFormatMagnitude) <= absValue && absValue < Math.pow(10, simpleFormatMagnitude);
 
-        if (fixedFormat) {
+        final int effectivePrecision = precision == NO_ROUNDING ? MAX_PRECISION : precision;
-            final int newScale = (int) (precision * Math.max(1, radix / 10f));
+        if (simpleFormat) {
+            final int newScale = (int) (effectivePrecision * Math.max(1, radix / 10f));
             value = BigDecimal.valueOf(value).setScale(newScale, BigDecimal.ROUND_HALF_UP).doubleValue();
             absValue = Math.abs(value);
         }
-        numberFormat.fse = fixedFormat ? FSE_FIX : FSE_ENG;
+        if (simpleFormat) {
+            numberFormat.fse = FSE_FIX;
+        } else if (format == FSE_NONE) {
+            // originally, a simple format was requested but we have to use something more appropriate, f.e. scientific
+            // format
+            numberFormat.fse = FSE_SCI;
+        } else {
+            numberFormat.fse = format;
+        }
         numberFormat.thousand = groupingSeparator;
-        numberFormat.precision = precision;
+        numberFormat.precision = effectivePrecision;
         numberFormat.base = radix;
-        numberFormat.maxwidth = fixedFormat ? 100 : 30;
+        numberFormat.maxwidth = simpleFormat ? 100 : 30;
 
         if (radix == 2 && value < 0) {
             return "-" + prepare(absValue);
@@ -69,6 +84,23 @@ public class NumberFormatter {
         return prepare(value);
     }
 
+    private boolean useSimpleFormat(int radix, double absValue) {
+        if (radix != 10) {
+            return true;
+        }
+        if (absValue < pow(10, -MAX_PRECISION)) {
+            // should never use simple format for small numbers
+            return false;
+        }
+        if (format == FSE_NONE) {
+            return true;
+        }
+        if (pow(10, -simpleFormatMagnitude) <= absValue && absValue < pow(10, simpleFormatMagnitude)) {
+            return true;
+        }
+        return false;
+    }
+
     @Nonnull
     private CharSequence prepare(double value) {
         return stripZeros(realFormat(value)).replace('e', 'E');

jscl/src/test/java/jscl/JsclMathEngineTest.java

@@ -1,5 +1,6 @@
 package jscl;
 
+import midpcalc.Real;
 import org.junit.Test;
 
 import static org.junit.Assert.assertEquals;
@@ -85,7 +86,7 @@ public class JsclMathEngineTest {
     @Test
     public void testEngineeringNotationWithRounding() throws Exception {
         final JsclMathEngine me = JsclMathEngine.getInstance();
-        me.setScienceNotation(true);
+        me.setNumberFormat(Real.NumberFormat.FSE_ENG);
         me.setRoundResult(true);
         me.setPrecision(5);
 
@@ -141,7 +142,7 @@ public class JsclMathEngineTest {
     @Test
     public void testEngineeringNotationWithoutRounding() throws Exception {
         final JsclMathEngine me = JsclMathEngine.getInstance();
-        me.setScienceNotation(true);
+        me.setNumberFormat(Real.NumberFormat.FSE_ENG);
         me.setRoundResult(false);
 
         assertEquals("10E6", me.format(10000000d));

jscl/src/test/java/org/solovyev/common/NumberFormatterTest.java

@@ -3,7 +3,10 @@ package org.solovyev.common;
 import org.junit.Before;
 import org.junit.Test;
 
+import static java.lang.Math.pow;
 import static org.junit.Assert.assertEquals;
+import static org.solovyev.common.NumberFormatter.DEFAULT_MAGNITUDE;
+import static org.solovyev.common.NumberFormatter.NO_ROUNDING;
 
 public class NumberFormatterTest {
 
@@ -25,12 +28,109 @@ public class NumberFormatterTest {
     }
 
     @Test
-    public void testSimpleFormat() throws Exception {
+    public void testScientificFormatNoRounding() throws Exception {
+        numberFormatter.useScientificFormat(DEFAULT_MAGNITUDE);
+        numberFormatter.setPrecision(NO_ROUNDING);
+
+        assertEquals("1", numberFormatter.format(1d));
+        assertEquals("0.3333333333333333", numberFormatter.format(1d / 3));
+        assertEquals("3.333333333333333E-19", numberFormatter.format(pow(10, -18) / 3));
+        assertEquals("1.23456789E18", numberFormatter.format(123456789 * pow(10, 10)));
+        assertEquals("1E-16", numberFormatter.format(pow(10, -16)));
+        assertEquals("5.9999999999999949E18", numberFormatter.format(5999999999999994999d));
+
+        testScientificFormat();
+    }
+
+    @Test
+    public void testScientificFormatWithRounding() throws Exception {
+        numberFormatter.useScientificFormat(DEFAULT_MAGNITUDE);
+        numberFormatter.setPrecision(5);
+
+        assertEquals("1", numberFormatter.format(1d));
+        assertEquals("0.33333", numberFormatter.format(1d / 3));
+        assertEquals("3.33333E-19", numberFormatter.format(pow(10, -18) / 3));
+        assertEquals("1.23457E18", numberFormatter.format(123456789 * pow(10, 10)));
+        assertEquals("1E-16", numberFormatter.format(pow(10, -16)));
+        assertEquals("6E18", numberFormatter.format(5999999999999994999d));
+
+
+        testScientificFormat();
+    }
+
+    @Test
+    public void testSimpleFormatNoRounding() throws Exception {
         numberFormatter.useSimpleFormat();
+        numberFormatter.setPrecision(NO_ROUNDING);
+
+        assertEquals("1", numberFormatter.format(1d));
+        assertEquals("0.000001", numberFormatter.format(pow(10, -6)));
+        assertEquals("0.3333333333333333", numberFormatter.format(1d / 3));
+        assertEquals("3.333333333333333E-19", numberFormatter.format(pow(10, -18) / 3));
+        assertEquals("1234567890000000000", numberFormatter.format(123456789 * pow(10, 10)));
+        assertEquals("0.0000000000000001", numberFormatter.format(pow(10, -16)));
+
+        testSimpleFormat();
+    }
+
+    @Test
+    public void testSimpleFormatWithRounding() throws Exception {
+        numberFormatter.useSimpleFormat();
+        numberFormatter.setPrecision(5);
+
+        assertEquals("1", numberFormatter.format(1d));
+        assertEquals("0", numberFormatter.format(pow(10, -6)));
+        assertEquals("0.33333", numberFormatter.format(1d / 3));
+        assertEquals("3.33333E-19", numberFormatter.format(pow(10, -18) / 3));
+        assertEquals("1234567890000000000", numberFormatter.format(123456789 * pow(10, 10)));
+        assertEquals("0", numberFormatter.format(pow(10, -16)));
+
+        testSimpleFormat();
+    }
+
+    // testing simple format with and without rounding
+    private void testSimpleFormat() {
+        assertEquals("0.00001", numberFormatter.format(pow(10, -5)));
+        assertEquals("100", numberFormatter.format(pow(10, 2)));
+        assertEquals("1000000000000000000", numberFormatter.format(pow(10, 18)));
+        assertEquals("1E19", numberFormatter.format(pow(10, 19)));
+        assertEquals("1E20", numberFormatter.format(pow(10, 20)));
+        assertEquals("1E100", numberFormatter.format(pow(10, 100)));
+
+        assertEquals("0.01", numberFormatter.format(pow(10, -2)));
+        assertEquals("1E-17", numberFormatter.format(pow(10, -17)));
+        assertEquals("1E-18", numberFormatter.format(pow(10, -18)));
+        assertEquals("1.5E-18", numberFormatter.format(1.5 * pow(10, -18)));
+        assertEquals("1E-100", numberFormatter.format(pow(10, -100)));
+
         assertEquals("5000000000000000000", numberFormatter.format(5000000000000000000d));
         assertEquals("5000000000000000000", numberFormatter.format(5000000000000000001d));
         assertEquals("5999999999999994900", numberFormatter.format(5999999999999994999d));
         assertEquals("5E19", numberFormatter.format(50000000000000000000d));
         assertEquals("5E40", numberFormatter.format(50000000000000000000000000000000000000000d));
     }
+
+    // testing scientific format with and without rounding
+    private void testScientificFormat() {
+        assertEquals("0.00001", numberFormatter.format(pow(10, -5)));
+        assertEquals("1E-6", numberFormatter.format(pow(10, -6)));
+        assertEquals("100", numberFormatter.format(pow(10, 2)));
+        assertEquals("10000", numberFormatter.format(pow(10, 4)));
+        assertEquals("1E5", numberFormatter.format(pow(10, 5)));
+        assertEquals("1E18", numberFormatter.format(pow(10, 18)));
+        assertEquals("1E19", numberFormatter.format(pow(10, 19)));
+        assertEquals("1E20", numberFormatter.format(pow(10, 20)));
+        assertEquals("1E100", numberFormatter.format(pow(10, 100)));
+
+        assertEquals("0.01", numberFormatter.format(pow(10, -2)));
+        assertEquals("1E-17", numberFormatter.format(pow(10, -17)));
+        assertEquals("1E-18", numberFormatter.format(pow(10, -18)));
+        assertEquals("1.5E-18", numberFormatter.format(1.5 * pow(10, -18)));
+        assertEquals("1E-100", numberFormatter.format(pow(10, -100)));
+
+        assertEquals("5E18", numberFormatter.format(5000000000000000000d));
+        assertEquals("5E18", numberFormatter.format(5000000000000000001d));
+        assertEquals("5E19", numberFormatter.format(50000000000000000000d));
+        assertEquals("5E40", numberFormatter.format(50000000000000000000000000000000000000000d));
+    }
 }