diff --git a/lib/.idea/workspace.xml b/lib/.idea/workspace.xml
index 47112c92db2311bf9976682c637b0c7a94e6dd53..1146c8d6b41ba0b7650f70351600ae427e680040 100755
--- a/lib/.idea/workspace.xml
+++ b/lib/.idea/workspace.xml
@@ -6,12 +6,12 @@
   <component name="CMakeRunConfigurationManager" shouldGenerate="true" shouldDeleteObsolete="true">
     <generated>
       <config projectName="project" targetName="star_tests" />
+      <config projectName="project" targetName="galaxy" />
       <config projectName="project" targetName="galaxy_tests" />
       <config projectName="project" targetName="quad_tree_tests" />
       <config projectName="project" targetName="vector_tests" />
-      <config projectName="project" targetName="node_tests" />
       <config projectName="project" targetName="box_tests" />
-      <config projectName="project" targetName="galaxy" />
+      <config projectName="project" targetName="node_tests" />
     </generated>
   </component>
   <component name="CMakeSettings">
@@ -22,8 +22,8 @@
   <component name="ChangeListManager">
     <list default="true" id="66aa4989-1799-4160-8419-e9cbdc309215" name="Default Changelist" comment="">
       <change beforePath="$PROJECT_DIR$/.idea/workspace.xml" beforeDir="false" afterPath="$PROJECT_DIR$/.idea/workspace.xml" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/node.c" beforeDir="false" afterPath="$PROJECT_DIR$/node.c" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/quad_tree.c" beforeDir="false" afterPath="$PROJECT_DIR$/quad_tree.c" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/galaxy.c" beforeDir="false" afterPath="$PROJECT_DIR$/galaxy.c" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/main.c" beforeDir="false" afterPath="$PROJECT_DIR$/main.c" afterDir="false" />
     </list>
     <ignored path="$PROJECT_DIR$/cmake-build-debug/" />
     <option name="EXCLUDED_CONVERTED_TO_IGNORED" value="true" />
@@ -40,11 +40,11 @@
     <splitter split-orientation="horizontal" split-proportion="0.7764787">
       <split-first>
         <leaf SIDE_TABS_SIZE_LIMIT_KEY="300">
-          <file pinned="false" current-in-tab="false">
+          <file pinned="false" current-in-tab="true">
             <entry file="file://$PROJECT_DIR$/main.c">
               <provider selected="true" editor-type-id="text-editor">
-                <state relative-caret-position="270">
-                  <caret line="18" column="16" selection-start-line="18" selection-start-column="16" selection-end-line="18" selection-end-column="16" />
+                <state relative-caret-position="330">
+                  <caret line="22" column="61" selection-start-line="22" selection-start-column="61" selection-end-line="22" selection-end-column="61" />
                   <folding>
                     <element signature="e#0#18#0" expanded="true" />
                   </folding>
@@ -52,7 +52,7 @@
               </provider>
             </entry>
           </file>
-          <file pinned="false" current-in-tab="true">
+          <file pinned="false" current-in-tab="false">
             <entry file="file://$PROJECT_DIR$/quad_tree.c">
               <provider selected="true" editor-type-id="text-editor">
                 <state relative-caret-position="660">
@@ -64,8 +64,8 @@
           <file pinned="false" current-in-tab="false">
             <entry file="file://$PROJECT_DIR$/node.c">
               <provider selected="true" editor-type-id="text-editor">
-                <state relative-caret-position="1140">
-                  <caret line="80" column="25" lean-forward="true" selection-start-line="80" selection-start-column="25" selection-end-line="80" selection-end-column="25" />
+                <state relative-caret-position="1200">
+                  <caret line="80" column="25" selection-start-line="80" selection-start-column="25" selection-end-line="80" selection-end-column="25" />
                 </state>
               </provider>
             </entry>
@@ -73,8 +73,8 @@
           <file pinned="false" current-in-tab="false">
             <entry file="file://$PROJECT_DIR$/galaxy.c">
               <provider selected="true" editor-type-id="text-editor">
-                <state relative-caret-position="208">
-                  <caret line="99" column="1" selection-start-line="99" selection-start-column="1" selection-end-line="99" selection-end-column="1" />
+                <state relative-caret-position="1860">
+                  <caret line="124" column="51" selection-start-line="124" selection-start-column="51" selection-end-line="124" selection-end-column="51" />
                   <folding>
                     <element signature="e#40#59#0" expanded="true" />
                   </folding>
@@ -85,8 +85,8 @@
           <file pinned="false" current-in-tab="false">
             <entry file="file://$PROJECT_DIR$/star.c">
               <provider selected="true" editor-type-id="text-editor">
-                <state relative-caret-position="553">
-                  <caret line="76" lean-forward="true" selection-start-line="76" selection-end-line="76" />
+                <state relative-caret-position="1140">
+                  <caret line="76" selection-start-line="76" selection-end-line="76" />
                   <folding>
                     <element signature="e#41#60#0" expanded="true" />
                   </folding>
@@ -97,7 +97,7 @@
           <file pinned="false" current-in-tab="false">
             <entry file="file://$PROJECT_DIR$/box.c">
               <provider selected="true" editor-type-id="text-editor">
-                <state relative-caret-position="298">
+                <state relative-caret-position="510">
                   <caret line="34" column="4" selection-start-line="34" selection-start-column="4" selection-end-line="34" selection-end-column="4" />
                   <folding>
                     <element signature="e#41#60#0" expanded="true" />
@@ -109,7 +109,7 @@
           <file pinned="false" current-in-tab="false">
             <entry file="file://$PROJECT_DIR$/vector.c">
               <provider selected="true" editor-type-id="text-editor">
-                <state relative-caret-position="-62">
+                <state relative-caret-position="255">
                   <caret line="17" selection-start-line="17" selection-end-line="17" />
                 </state>
               </provider>
@@ -202,13 +202,13 @@
         <option value="$PROJECT_DIR$/box_tests.c" />
         <option value="$PROJECT_DIR$/Makefile" />
         <option value="$PROJECT_DIR$/box.c" />
-        <option value="$PROJECT_DIR$/main.c" />
         <option value="$PROJECT_DIR$/vector.c" />
         <option value="$PROJECT_DIR$/vector.h" />
-        <option value="$PROJECT_DIR$/galaxy.c" />
         <option value="$PROJECT_DIR$/star.c" />
         <option value="$PROJECT_DIR$/node.c" />
         <option value="$PROJECT_DIR$/quad_tree.c" />
+        <option value="$PROJECT_DIR$/galaxy.c" />
+        <option value="$PROJECT_DIR$/main.c" />
       </list>
     </option>
   </component>
@@ -227,6 +227,7 @@
       <foldersAlwaysOnTop value="true" />
     </navigator>
     <panes>
+      <pane id="Scope" />
       <pane id="ProjectPane">
         <subPane>
           <expand>
@@ -243,7 +244,6 @@
           <select />
         </subPane>
       </pane>
-      <pane id="Scope" />
     </panes>
   </component>
   <component name="PropertiesComponent">
@@ -349,7 +349,8 @@
       <workItem from="1560630172137" duration="556000" />
       <workItem from="1560786024968" duration="1037000" />
       <workItem from="1560804972006" duration="6248000" />
-      <workItem from="1560835151095" duration="355000" />
+      <workItem from="1560835151095" duration="1145000" />
+      <workItem from="1560840111434" duration="59000" />
     </task>
     <task id="LOCAL-00001" summary="update general">
       <created>1560551622745</created>
@@ -372,17 +373,24 @@
       <option name="project" value="LOCAL" />
       <updated>1560811281384</updated>
     </task>
-    <option name="localTasksCounter" value="4" />
+    <task id="LOCAL-00004" summary="commentaire">
+      <created>1560835519919</created>
+      <option name="number" value="00004" />
+      <option name="presentableId" value="LOCAL-00004" />
+      <option name="project" value="LOCAL" />
+      <updated>1560835519919</updated>
+    </task>
+    <option name="localTasksCounter" value="5" />
     <servers />
   </component>
   <component name="TimeTrackingManager">
-    <option name="totallyTimeSpent" value="66282000" />
+    <option name="totallyTimeSpent" value="67131000" />
   </component>
   <component name="ToolWindowManager">
     <frame x="67" y="25" width="1853" height="1055" extended-state="6" />
     <editor active="true" />
     <layout>
-      <window_info active="true" content_ui="combo" id="Project" order="0" visible="true" weight="0.044825677" />
+      <window_info content_ui="combo" id="Project" order="0" visible="true" weight="0.04537908" />
       <window_info id="Structure" order="1" side_tool="true" weight="0.25" />
       <window_info id="Favorites" order="2" side_tool="true" />
       <window_info anchor="bottom" id="Message" order="0" />
@@ -394,7 +402,7 @@
       <window_info anchor="bottom" id="TODO" order="6" />
       <window_info anchor="bottom" id="Database Changes" order="7" />
       <window_info anchor="bottom" id="Event Log" order="8" side_tool="true" />
-      <window_info anchor="bottom" id="Terminal" order="9" visible="true" weight="0.116630666" />
+      <window_info active="true" anchor="bottom" id="Terminal" order="9" visible="true" weight="0.116630666" />
       <window_info anchor="bottom" id="Version Control" order="10" />
       <window_info anchor="bottom" id="CMake" order="11" />
       <window_info anchor="bottom" id="Messages" order="12" weight="0.3261339" />
@@ -451,115 +459,115 @@
         </state>
       </provider>
     </entry>
-    <entry file="file://$PROJECT_DIR$/main.c">
+    <entry file="file://$PROJECT_DIR$/vector_tests.c">
+      <provider selected="true" editor-type-id="text-editor" />
+    </entry>
+    <entry file="file://$PROJECT_DIR$/box_tests.c">
       <provider selected="true" editor-type-id="text-editor">
-        <state relative-caret-position="270">
-          <caret line="18" column="16" selection-start-line="18" selection-start-column="16" selection-end-line="18" selection-end-column="16" />
-          <folding>
-            <element signature="e#0#18#0" expanded="true" />
-          </folding>
+        <state relative-caret-position="45">
+          <caret line="3" selection-start-line="3" selection-end-line="3" />
         </state>
       </provider>
     </entry>
-    <entry file="file://$PROJECT_DIR$/Makefile">
+    <entry file="file://$PROJECT_DIR$/quad_tree_tests.c">
       <provider selected="true" editor-type-id="text-editor">
-        <state relative-caret-position="450">
-          <caret line="30" column="211" selection-start-line="30" selection-start-column="211" selection-end-line="30" selection-end-column="211" />
+        <state relative-caret-position="30">
+          <caret line="2" selection-start-line="2" selection-end-line="4" selection-end-column="1" />
         </state>
       </provider>
     </entry>
-    <entry file="file://$PROJECT_DIR$/vector.h">
+    <entry file="file://$PROJECT_DIR$/node.c">
       <provider selected="true" editor-type-id="text-editor">
-        <state relative-caret-position="180">
-          <caret line="12" selection-start-line="12" selection-end-line="12" />
+        <state relative-caret-position="1200">
+          <caret line="80" column="25" selection-start-line="80" selection-start-column="25" selection-end-line="80" selection-end-column="25" />
         </state>
       </provider>
     </entry>
-    <entry file="file://$PROJECT_DIR$/node.h">
+    <entry file="file://$PROJECT_DIR$/galaxy.c">
       <provider selected="true" editor-type-id="text-editor">
-        <state relative-caret-position="300">
-          <caret line="20" column="11" selection-start-line="20" selection-start-column="11" selection-end-line="20" selection-end-column="11" />
+        <state relative-caret-position="1860">
+          <caret line="124" column="51" selection-start-line="124" selection-start-column="51" selection-end-line="124" selection-end-column="51" />
+          <folding>
+            <element signature="e#40#59#0" expanded="true" />
+          </folding>
         </state>
       </provider>
     </entry>
-    <entry file="file://$PROJECT_DIR$/vector_tests.c">
-      <provider selected="true" editor-type-id="text-editor" />
-    </entry>
-    <entry file="file://$PROJECT_DIR$/galaxy.h">
-      <provider selected="true" editor-type-id="text-editor" />
-    </entry>
-    <entry file="file://$PROJECT_DIR$/box.h">
+    <entry file="file://$PROJECT_DIR$/star.c">
       <provider selected="true" editor-type-id="text-editor">
-        <state relative-caret-position="330">
-          <caret line="22" column="31" selection-start-line="22" selection-start-column="31" selection-end-line="22" selection-end-column="31" />
+        <state relative-caret-position="1140">
+          <caret line="76" selection-start-line="76" selection-end-line="76" />
           <folding>
-            <element signature="e#102#121#0" expanded="true" />
+            <element signature="e#41#60#0" expanded="true" />
           </folding>
         </state>
       </provider>
     </entry>
-    <entry file="file://$PROJECT_DIR$/box_tests.c">
+    <entry file="file://$PROJECT_DIR$/box.c">
       <provider selected="true" editor-type-id="text-editor">
-        <state relative-caret-position="45">
-          <caret line="3" selection-start-line="3" selection-end-line="3" />
+        <state relative-caret-position="510">
+          <caret line="34" column="4" selection-start-line="34" selection-start-column="4" selection-end-line="34" selection-end-column="4" />
+          <folding>
+            <element signature="e#41#60#0" expanded="true" />
+          </folding>
         </state>
       </provider>
     </entry>
-    <entry file="file://$PROJECT_DIR$/quad_tree_tests.c">
+    <entry file="file://$PROJECT_DIR$/vector.c">
       <provider selected="true" editor-type-id="text-editor">
-        <state relative-caret-position="30">
-          <caret line="2" selection-start-line="2" selection-end-line="4" selection-end-column="1" />
+        <state relative-caret-position="255">
+          <caret line="17" selection-start-line="17" selection-end-line="17" />
         </state>
       </provider>
     </entry>
-    <entry file="file://$PROJECT_DIR$/vector.c">
+    <entry file="file://$PROJECT_DIR$/Makefile">
       <provider selected="true" editor-type-id="text-editor">
-        <state relative-caret-position="-62">
-          <caret line="17" selection-start-line="17" selection-end-line="17" />
+        <state relative-caret-position="450">
+          <caret line="30" column="211" selection-start-line="30" selection-start-column="211" selection-end-line="30" selection-end-column="211" />
         </state>
       </provider>
     </entry>
-    <entry file="file://$PROJECT_DIR$/box.c">
+    <entry file="file://$PROJECT_DIR$/quad_tree.c">
       <provider selected="true" editor-type-id="text-editor">
-        <state relative-caret-position="298">
-          <caret line="34" column="4" selection-start-line="34" selection-start-column="4" selection-end-line="34" selection-end-column="4" />
-          <folding>
-            <element signature="e#41#60#0" expanded="true" />
-          </folding>
+        <state relative-caret-position="660">
+          <caret line="50" column="32" selection-start-line="50" selection-start-column="32" selection-end-line="50" selection-end-column="32" />
         </state>
       </provider>
     </entry>
-    <entry file="file://$PROJECT_DIR$/star.c">
+    <entry file="file://$PROJECT_DIR$/box.h">
       <provider selected="true" editor-type-id="text-editor">
-        <state relative-caret-position="553">
-          <caret line="76" lean-forward="true" selection-start-line="76" selection-end-line="76" />
+        <state relative-caret-position="330">
+          <caret line="22" column="31" selection-start-line="22" selection-start-column="31" selection-end-line="22" selection-end-column="31" />
           <folding>
-            <element signature="e#41#60#0" expanded="true" />
+            <element signature="e#102#121#0" expanded="true" />
           </folding>
         </state>
       </provider>
     </entry>
-    <entry file="file://$PROJECT_DIR$/node.c">
+    <entry file="file://$PROJECT_DIR$/galaxy.h">
+      <provider selected="true" editor-type-id="text-editor" />
+    </entry>
+    <entry file="file://$PROJECT_DIR$/vector.h">
       <provider selected="true" editor-type-id="text-editor">
-        <state relative-caret-position="1140">
-          <caret line="80" column="25" lean-forward="true" selection-start-line="80" selection-start-column="25" selection-end-line="80" selection-end-column="25" />
+        <state relative-caret-position="180">
+          <caret line="12" selection-start-line="12" selection-end-line="12" />
         </state>
       </provider>
     </entry>
-    <entry file="file://$PROJECT_DIR$/galaxy.c">
+    <entry file="file://$PROJECT_DIR$/node.h">
       <provider selected="true" editor-type-id="text-editor">
-        <state relative-caret-position="208">
-          <caret line="99" column="1" selection-start-line="99" selection-start-column="1" selection-end-line="99" selection-end-column="1" />
-          <folding>
-            <element signature="e#40#59#0" expanded="true" />
-          </folding>
+        <state relative-caret-position="300">
+          <caret line="20" column="11" selection-start-line="20" selection-start-column="11" selection-end-line="20" selection-end-column="11" />
         </state>
       </provider>
     </entry>
-    <entry file="file://$PROJECT_DIR$/quad_tree.c">
+    <entry file="file://$PROJECT_DIR$/main.c">
       <provider selected="true" editor-type-id="text-editor">
-        <state relative-caret-position="660">
-          <caret line="50" column="32" selection-start-line="50" selection-start-column="32" selection-end-line="50" selection-end-column="32" />
+        <state relative-caret-position="330">
+          <caret line="22" column="61" selection-start-line="22" selection-start-column="61" selection-end-line="22" selection-end-column="61" />
+          <folding>
+            <element signature="e#0#18#0" expanded="true" />
+          </folding>
         </state>
       </provider>
     </entry>
diff --git a/lib/galaxy.c b/lib/galaxy.c
index fef065d14be1319dfe23db3711b0259791eb23c6..bcd01242a10051ac48310d8e28e3c61c9e6643ed 100755
--- a/lib/galaxy.c
+++ b/lib/galaxy.c
@@ -58,7 +58,7 @@ galaxy *create_and_init_galaxy(int num_bodies, box *b, double dt) {
 
         new_galaxy->stars[i] = new_star_vel(pos, vel, new_vec(0.0, 0.0), mass, dt);
 
-        free_vec(vel);
+        free_vec(vel);   //libere memoire
 
     }
 
@@ -94,7 +94,7 @@ star *new_rand_star(double dt) {
 
 void reset_accelerations(galaxy *g) {
     for (int i = 0; i < g->num_bodies; ++i) {
-        reset_acceleration(g->stars[i]);     //appels la fonction update_acc_(star) pour toute les etoile
+        reset_acceleration(g->stars[i]);     //appels la fonction rest_acc_(star) pour toute les etoile
     }
 
 }
diff --git a/lib/main.c b/lib/main.c
index abbb6466a370eb69909982ede02fe07a61b728e4..455c1a5aec5f4867eaadbbff967e0c534344ac15 100755
--- a/lib/main.c
+++ b/lib/main.c
@@ -20,7 +20,7 @@ int main(int argc, char *argv[]) {
     double theta = atof(argv[2]);
 
 
-    struct gfx_context_t *context = gfx_create("Random Image", SIZE_W, SIZE_H);
+    struct gfx_context_t *context = gfx_create("Random Galaxy", SIZE_W, SIZE_H);
     if (!context) {
         fprintf(stderr, "Graphic mode initialization failed!\n");
         EXIT_FAILURE;