diff --git a/.idea/Numerical.iml b/.idea/Numerical.iml
index 4f21c2d..d06e659 100644
--- a/.idea/Numerical.iml
+++ b/.idea/Numerical.iml
@@ -2,7 +2,7 @@
 <module type="PYTHON_MODULE" version="4">
   <component name="NewModuleRootManager">
     <content url="file://$MODULE_DIR$" />
-    <orderEntry type="jdk" jdkName="Python 2.7.6 virtualenv at ~/.virtualenvs/env0" jdkType="Python SDK" />
+    <orderEntry type="jdk" jdkName="Python 2.7.8 virtualenv at ~/.virtualenvs/env0" jdkType="Python SDK" />
     <orderEntry type="sourceFolder" forTests="false" />
   </component>
 </module>
\ No newline at end of file
diff --git a/.idea/encodings.xml b/.idea/encodings.xml
new file mode 100644
index 0000000..d821048
--- /dev/null
+++ b/.idea/encodings.xml
@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="Encoding" useUTFGuessing="true" native2AsciiForPropertiesFiles="false" />
+</project>
\ No newline at end of file
diff --git a/.idea/misc.xml b/.idea/misc.xml
index cd9d35b..0a82ef1 100644
--- a/.idea/misc.xml
+++ b/.idea/misc.xml
@@ -1,5 +1,12 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
+  <component name="DaemonCodeAnalyzer">
+    <disable_hints />
+  </component>
+  <component name="DependencyValidationManager">
+    <option name="SKIP_IMPORT_STATEMENTS" value="false" />
+  </component>
+  <component name="Encoding" useUTFGuessing="true" native2AsciiForPropertiesFiles="false" />
   <component name="ProjectLevelVcsManager" settingsEditedManually="false">
     <OptionsSetting value="true" id="Add" />
     <OptionsSetting value="true" id="Remove" />
@@ -10,5 +17,11 @@
     <ConfirmationsSetting value="0" id="Add" />
     <ConfirmationsSetting value="0" id="Remove" />
   </component>
-  <component name="ProjectRootManager" version="2" project-jdk-name="Python 2.7.6 (/usr/bin/python2.7)" project-jdk-type="Python SDK" />
+  <component name="ProjectModuleManager">
+    <modules />
+  </component>
+  <component name="ProjectRootManager" version="2" project-jdk-name="Python 2.6.6 (/usr/bin/python)" project-jdk-type="Python SDK" />
+  <component name="RunManager">
+    <list size="0" />
+  </component>
 </project>
\ No newline at end of file
diff --git a/.idea/scopes/scope_settings.xml b/.idea/scopes/scope_settings.xml
new file mode 100644
index 0000000..922003b
--- /dev/null
+++ b/.idea/scopes/scope_settings.xml
@@ -0,0 +1,5 @@
+<component name="DependencyValidationManager">
+  <state>
+    <option name="SKIP_IMPORT_STATEMENTS" value="false" />
+  </state>
+</component>
\ No newline at end of file
diff --git a/.idea/workspace.xml b/.idea/workspace.xml
index a39b29c..2bc51f9 100644
--- a/.idea/workspace.xml
+++ b/.idea/workspace.xml
@@ -11,8 +11,8 @@
   <component name="CreatePatchCommitExecutor">
     <option name="PATCH_PATH" value="" />
   </component>
-  <component name="NamedScopeManager">
-    <order />
+  <component name="DaemonCodeAnalyzer">
+    <disable_hints />
   </component>
   <component name="ProjectLevelVcsManager" settingsEditedManually="false">
     <OptionsSetting value="true" id="Add" />
@@ -24,18 +24,24 @@
     <ConfirmationsSetting value="0" id="Add" />
     <ConfirmationsSetting value="0" id="Remove" />
   </component>
+  <component name="RunManager">
+    <list size="0" />
+  </component>
   <component name="ShelveChangesManager" show_recycled="false" />
   <component name="TaskManager">
     <task active="true" id="Default" summary="Default task">
-      <created>1434792298659</created>
       <option name="number" value="Default" />
-      <updated>1434792298659</updated>
     </task>
     <servers />
   </component>
   <component name="VcsContentAnnotationSettings">
     <option name="myLimit" value="2678400000" />
   </component>
+  <component name="VcsManagerConfiguration">
+    <option name="myTodoPanelSettings">
+      <TodoPanelSettings />
+    </option>
+  </component>
   <component name="XDebuggerManager">
     <breakpoint-manager />
     <watches-manager />
diff --git a/chap1/1_3_infiniteseries.py b/chap1/1_3_infiniteseries.py
index 4c4ed0b..3b6d040 100644
--- a/chap1/1_3_infiniteseries.py
+++ b/chap1/1_3_infiniteseries.py
@@ -1,7 +1,7 @@
 __author__ = 'chunk'
 
 import struct
-
+import numpy as np
 
 def float2bits(f, fmt='bin'):
     if fmt == 'hex':
@@ -30,14 +30,13 @@ def double2bin(num):
 
 
 def infiniteseries():
-    s = 0
-    tmp = -1
+    s = np.float32(0)
+    tmp = np.float32(-1)
     i = 0
-    while float(s) != float(tmp):
+    while s != tmp:
         i += 1
         tmp = s
-        s += float(1.0 / i)
-        print tmp,s
+        s += np.float32(1.0 / i)
 
     print i, s, tmp
 
--
libgit2 0.21.2