ImgMath: new math operations Log and Exp.

Not based on NumericType math as it lacks these functions.
Uses RealType.setReal and RealType.getRealDouble(), which is
the standard approach as used by e.g.
net.imglib2.util.Util.genericRealTypeConverter.

Author: acardona

src/main/java/net/imglib2/algorithm/math/Exp.java

@@ -0,0 +1,30 @@
+package net.imglib2.algorithm.math;
+
+import java.util.Map;
+
+import net.imglib2.algorithm.math.abstractions.AUnaryFunction;
+import net.imglib2.algorithm.math.abstractions.OFunction;
+import net.imglib2.algorithm.math.execution.Exponential;
+import net.imglib2.algorithm.math.execution.LetBinding;
+import net.imglib2.algorithm.math.execution.Variable;
+import net.imglib2.converter.Converter;
+import net.imglib2.type.numeric.RealType;
+
+public final class Exp extends AUnaryFunction
+{
+	public Exp( final Object o1 )
+	{
+		super( o1 );
+	}
+
+	@Override
+	public < O extends RealType< O > > Exponential< O > reInit(
+			final O tmp,
+			final Map< String, LetBinding< O > > bindings,
+			final Converter< RealType< ? >, O > converter,
+			final Map< Variable< O >, OFunction< O > > imgSources )
+	{
+		return new Exponential< O >( tmp.copy(),
+				this.a.reInit( tmp, bindings, converter, imgSources ) );
+	}
+}

src/main/java/net/imglib2/algorithm/math/ImgMath.java

@@ -209,6 +209,21 @@ static public final Min minimum( final Object... obs )
 		return new Min( obs );
 	}
 
+	static public final Log log( final Object o1 )
+	{
+		return new Log( o1 );
+	}
+	
+	static public final Log logarithm( final Object o1 )
+	{
+		return new Log( o1 );
+	}
+	
+	static public final Exp exp( final Object o1 )
+	{
+		return new Exp( o1 );
+	}
+	
 	static public final Let let( final String varName, final Object varValue, final Object body )
 	{
 		return new Let( varName, varValue, body );

src/main/java/net/imglib2/algorithm/math/Log.java

@@ -0,0 +1,30 @@
+package net.imglib2.algorithm.math;
+
+import java.util.Map;
+
+import net.imglib2.algorithm.math.abstractions.AUnaryFunction;
+import net.imglib2.algorithm.math.abstractions.OFunction;
+import net.imglib2.algorithm.math.execution.Logarithm;
+import net.imglib2.algorithm.math.execution.LetBinding;
+import net.imglib2.algorithm.math.execution.Variable;
+import net.imglib2.converter.Converter;
+import net.imglib2.type.numeric.RealType;
+
+public final class Log extends AUnaryFunction
+{
+	public Log( final Object o1 )
+	{
+		super( o1 );
+	}
+
+	@Override
+	public < O extends RealType< O > > Logarithm< O > reInit(
+			final O tmp,
+			final Map< String, LetBinding< O > > bindings,
+			final Converter< RealType< ? >, O > converter,
+			final Map< Variable< O >, OFunction< O > > imgSources )
+	{
+		return new Logarithm< O >( tmp.copy(),
+				this.a.reInit( tmp, bindings, converter, imgSources ) );
+	}
+}

src/main/java/net/imglib2/algorithm/math/execution/Exponential.java

@@ -0,0 +1,57 @@
+package net.imglib2.algorithm.math.execution;
+
+import java.util.Arrays;
+import java.util.List;
+
+import net.imglib2.Localizable;
+import net.imglib2.algorithm.math.abstractions.OFunction;
+import net.imglib2.type.numeric.RealType;
+
+/**
+ * Doesn't use {@code NumericType} math because it lacks the log function.
+ *
+ * @param <O>
+ */
+public class Exponential< O extends RealType< O > > implements OFunction< O >
+{
+	private final OFunction< O > a;
+	private final O scrap;
+	
+	public Exponential( final O scrap, final OFunction< O > a )
+	{
+		this.scrap = scrap;
+		this.a = a;
+	}
+	
+	@Override
+	public final O eval()
+	{
+		this.scrap.setReal( Math.exp( this.a.eval().getRealDouble() ) );
+		return this.scrap;
+	}
+
+	@Override
+	public final O eval( final Localizable loc )
+	{
+		this.scrap.setReal( Math.exp( this.a.eval( loc ).getRealDouble() ) );
+		return this.scrap;
+	}
+	
+	@Override
+	public List< OFunction< O > > children()
+	{
+		return Arrays.asList( this.a );
+	}
+	
+	@Override
+	public final double evalDouble()
+	{
+		return Math.exp( this.a.evalDouble() );
+	}
+	
+	@Override
+	public final double evalDouble( final Localizable loc )
+	{
+		return Math.exp( this.a.evalDouble( loc ) );
+	}
+}

src/main/java/net/imglib2/algorithm/math/execution/Logarithm.java

@@ -0,0 +1,57 @@
+package net.imglib2.algorithm.math.execution;
+
+import java.util.Arrays;
+import java.util.List;
+
+import net.imglib2.Localizable;
+import net.imglib2.algorithm.math.abstractions.OFunction;
+import net.imglib2.type.numeric.RealType;
+
+/**
+ * Doesn't use {@code NumericType} math because it lacks the log function.
+ *
+ * @param <O>
+ */
+public class Logarithm< O extends RealType< O > > implements OFunction< O >
+{
+	private final OFunction< O > a;
+	private final O scrap;
+	
+	public Logarithm( final O scrap, final OFunction< O > a )
+	{
+		this.scrap = scrap;
+		this.a = a;
+	}
+	
+	@Override
+	public final O eval()
+	{
+		this.scrap.setReal( Math.log( this.a.eval().getRealDouble() ) );
+		return this.scrap;
+	}
+
+	@Override
+	public final O eval( final Localizable loc )
+	{
+		this.scrap.setReal( Math.log( this.a.eval( loc ).getRealDouble() ) );
+		return this.scrap;
+	}
+	
+	@Override
+	public List< OFunction< O > > children()
+	{
+		return Arrays.asList( this.a );
+	}
+	
+	@Override
+	public final double evalDouble()
+	{
+		return Math.log( this.a.evalDouble() );
+	}
+	
+	@Override
+	public final double evalDouble( final Localizable loc )
+	{
+		return Math.log( this.a.evalDouble( loc ) );
+	}
+}