diff --git a/build.gradle b/build.gradle
index 92301f1..9b929f2 100644
--- a/build.gradle
+++ b/build.gradle
@@ -4,7 +4,7 @@ apply plugin: "maven"
 apply plugin: "signing"
 
 group 'com.github.sh0nk'
-version '0.4.1-SNAPSHOT'
+version '0.5.0-SNAPSHOT'
 archivesBaseName = "matplotlib4j"
 description = "Matplotlib for java: A simple graph plot library for java with powerful python matplotlib"
 
diff --git a/gradle/wrapper/gradle-wrapper.jar b/gradle/wrapper/gradle-wrapper.jar
index 57372f4..758de96 100644
Binary files a/gradle/wrapper/gradle-wrapper.jar and b/gradle/wrapper/gradle-wrapper.jar differ
diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
index 43264ac..ff553dc 100644
--- a/gradle/wrapper/gradle-wrapper.properties
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -1,6 +1,6 @@
-#Sun Sep 24 01:25:45 JST 2017
+#Wed Oct 23 10:40:47 UTC 2019
+distributionUrl=https\://services.gradle.org/distributions/gradle-4.8.1-all.zip
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-3.5-rc-2-all.zip
+zipStoreBase=GRADLE_USER_HOME
diff --git a/gradlew b/gradlew
index 4453cce..cccdd3d 100755
--- a/gradlew
+++ b/gradlew
@@ -33,11 +33,11 @@ DEFAULT_JVM_OPTS=""
 # Use the maximum available, or set MAX_FD != -1 to use that value.
 MAX_FD="maximum"
 
-warn ( ) {
+warn () {
     echo "$*"
 }
 
-die ( ) {
+die () {
     echo
     echo "$*"
     echo
@@ -155,7 +155,7 @@ if $cygwin ; then
 fi
 
 # Escape application args
-save ( ) {
+save () {
     for i do printf %s\\n "$i" | sed "s/'/'\\\\''/g;1s/^/'/;\$s/\$/' \\\\/" ; done
     echo " "
 }
diff --git a/src/main/java/com/github/sh0nk/matplotlib4j/PyCommand.java b/src/main/java/com/github/sh0nk/matplotlib4j/PyCommand.java
index b70cb0e..5d65c0a 100644
--- a/src/main/java/com/github/sh0nk/matplotlib4j/PyCommand.java
+++ b/src/main/java/com/github/sh0nk/matplotlib4j/PyCommand.java
@@ -7,6 +7,7 @@
 import org.slf4j.LoggerFactory;
 
 import java.io.*;
+import java.nio.charset.StandardCharsets;
 import java.nio.file.Paths;
 import java.util.List;
 import java.util.regex.Matcher;
@@ -88,7 +89,7 @@ private void command(List<String> commands) throws IOException, PythonExecutionE
     }
 
     private void writeFile(String pythonScript, File script) throws IOException {
-        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(script)));
+        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(script), StandardCharsets.UTF_8));
         bw.write(pythonScript);
         bw.close();
     }
diff --git a/src/main/java/com/github/sh0nk/matplotlib4j/TypeConversion.java b/src/main/java/com/github/sh0nk/matplotlib4j/TypeConversion.java
index 5cdc003..0d274dd 100644
--- a/src/main/java/com/github/sh0nk/matplotlib4j/TypeConversion.java
+++ b/src/main/java/com/github/sh0nk/matplotlib4j/TypeConversion.java
@@ -1,6 +1,7 @@
 package com.github.sh0nk.matplotlib4j;
 
 import java.util.List;
+import java.util.Locale;
 import java.util.stream.Collectors;
 
 public enum TypeConversion {
@@ -17,4 +18,8 @@ public List<Object> typeSafeList(List<? extends Number> orgList) {
             }
         }).collect(Collectors.toList());
     }
+
+    public String toSafeDouble(double d) {
+        return String.format(Locale.US, "%.6f", d);
+    }
 }
diff --git a/src/main/java/com/github/sh0nk/matplotlib4j/builder/HistBuilderImpl.java b/src/main/java/com/github/sh0nk/matplotlib4j/builder/HistBuilderImpl.java
index 1f1bcfe..b23ce0b 100644
--- a/src/main/java/com/github/sh0nk/matplotlib4j/builder/HistBuilderImpl.java
+++ b/src/main/java/com/github/sh0nk/matplotlib4j/builder/HistBuilderImpl.java
@@ -1,5 +1,6 @@
 package com.github.sh0nk.matplotlib4j.builder;
 
+import com.github.sh0nk.matplotlib4j.TypeConversion;
 import com.github.sh0nk.matplotlib4j.kwargs.PatchBuilder;
 import com.github.sh0nk.matplotlib4j.kwargs.PatchBuilderImpl;
 import com.google.common.base.Joiner;
@@ -33,7 +34,8 @@ public HistBuilder bins(List<? extends Number> nums) {
 
     @Override
     public HistBuilder range(double lower, double upper) {
-        return innerBuilder.addToKwargsWithoutQuoting("range", String.format("(%f, %f)", lower, upper));
+        return innerBuilder.addToKwargsWithoutQuoting("range", String.format("(%s, %s)",
+                        TypeConversion.INSTANCE.toSafeDouble(lower), TypeConversion.INSTANCE.toSafeDouble(upper)));
     }
 
     @Override
diff --git a/src/main/java/com/github/sh0nk/matplotlib4j/builder/LegendBuilderImpl.java b/src/main/java/com/github/sh0nk/matplotlib4j/builder/LegendBuilderImpl.java
index 5876621..b838ffc 100644
--- a/src/main/java/com/github/sh0nk/matplotlib4j/builder/LegendBuilderImpl.java
+++ b/src/main/java/com/github/sh0nk/matplotlib4j/builder/LegendBuilderImpl.java
@@ -1,5 +1,7 @@
 package com.github.sh0nk.matplotlib4j.builder;
 
+import com.github.sh0nk.matplotlib4j.TypeConversion;
+
 public class LegendBuilderImpl implements LegendBuilder {
 
     private CompositeBuilder<LegendBuilder> innerBuilder = new CompositeBuilder<>(this);
@@ -16,7 +18,8 @@ public LegendBuilder loc(String arg) {
 
     @Override
     public LegendBuilder loc(double x, double y) {
-        return innerBuilder.addToKwargsWithoutQuoting("loc", String.format("(%d, %d)", x, y));
+        return innerBuilder.addToKwargsWithoutQuoting("loc", String.format("(%s, %s)",
+                TypeConversion.INSTANCE.toSafeDouble(x), TypeConversion.INSTANCE.toSafeDouble(y)));
     }
 
     @Override