diff --git a/analysis/analyse.js b/analysis/analyse.js
index b0a2704..e1e153c 100644
--- a/analysis/analyse.js
+++ b/analysis/analyse.js
@@ -1,43 +1,9 @@
-// http://codereview.stackexchange.com/questions/37028/grouping-elements-in-array-by-multiple-properties
-function groupBy(array, f)
-{
-    var groups = {};
-    array.forEach(function(o) {
-        var group = JSON.stringify(f(o));
-        groups[group] = groups[group] || [];
-        groups[group].push(o);
-    });
-
-    return Object.keys(groups).map(function(group) {
-        return groups[group];
-    })
-}
-
-function compareRecommendationStyle(style1, style2) {
-
-    if (style1.recommendation_style[4] === 'B' && style2.recommendation_style[4] !== 'B') {
-        return -1;
-    }
-
-    if (style2.recommendation_style[4] === 'B' && style1.recommendation_style[4] !== 'B') {
-        return 1;
-    }
-
-    if (style1.recommendation_style[4] === 'V' && style2.recommendation_style[4] === 'A') {
-        return -1;
-    }
-
-    if (style2.recommendation_style[4] === 'V' && style1.recommendation_style[4] === 'A') {
-        return 1;
-    }
-
-    return 0;
-
-}
+var lib = require('./lib.js');
 
 function main(path) {
 
-    var db = JSON.parse(require('fs').readFileSync(path, 'utf8'));
+    var db = lib.loadFromFile(path);
+    var groups = lib.makeGroups(db);
 
     console.log(`There were ${db.users.length} users for ${db.experiments.length} experiments`);
 
@@ -45,7 +11,6 @@ function main(path) {
     var meanTimeArrow = 0;
     var meanTimeViewport = 0;
 
-    var groups = makeGroups(db);
 
     groups.forEach(function(elt) {
         var ok = true;
@@ -73,43 +38,6 @@ function main(path) {
     var value = minDifferences(groups);
     console.log(value);
 
-    // for (var i = 0; i < db.experiments.length; i++) {
-
-    //     var exp = db.experiments[i];
-    //     var events = exp.elements.events;
-
-    //     if (events.length === 0 || exp.user.worker_id === null) {
-
-    //         continue;
-
-    //     }
-
-    //     var coins = [];
-    //     for (var j = 0; j < exp.elements.events.length; j++) {
-
-    //         if (exp.elements.events[j].type === 'coin') {
-
-    //             if (coins.find(function(elt) { return elt.id === exp.elements.events[j].id; }) === undefined) {
-
-    //                 coins.push(exp.elements.events[j]);
-
-    //             }
-
-    //         }
-
-    //     }
-    //     console.log(`${exp.id} -> ${coins.length} (on ${exp.coinCombination.scene_id} )`);
-    // }
-
-    // console.log();
-
-    // for (var i = 0; i < db.users.length; i++) {
-
-    //     var user = db.users[i];
-    //     console.log(`${user.worker_id} has done ${user.experiments.length} experiments with rating ${user.rating}`);
-
-    // }
-
 }
 
 function minDifference(exps) {
@@ -179,54 +107,6 @@ function minDifferences(groups) {
 
 }
 
-function experimentDuration(exp) {
-    var lastCoin = null;
-
-    for (var i = exp.elements.events.length - 1; i >= 0; i--) {
-        if (exp.elements.events[i].type === 'coin') {
-            lastCoin = exp.elements.events[i];
-            break;
-        }
-    }
-
-    return timeDifference(exp.elements.events[0].time, lastCoin.time);
-
-}
-
-function timeDifference(time1, time2) {
-
-    return new Date(time2).getTime() - new Date(time1).getTime();
-
-}
-
-function timeToString(_time) {
-
-    var time = _time / 1000;
-
-    return Math.floor(time / 3600) + 'h' + Math.floor((time % 3600) / 60) + 'm' + Math.floor(time % 60);
-
-}
-
-function makeGroups(db) {
-
-    var elements = [];
-
-    for (var i = 0; i < db.experiments.length; i++) {
-
-        if (db.experiments[i].coinCombination.scene_id !== 1 && db.experiments[i].elements.events.length !== 0) {
-
-            elements.push(db.experiments[i]);
-
-        }
-
-    }
-
-    return groupBy(elements, function(item) {
-        return item.coin_combination_id;//, item.user.rating];
-    });
-
-}
-
 if (process.argv.length !== 3) {
     process.stderr.write('Error : please give me a JSON file to work on\n');
     process.exit(-1);
diff --git a/analysis/lib.js b/analysis/lib.js
new file mode 100644
index 0000000..3f9221a
--- /dev/null
+++ b/analysis/lib.js
@@ -0,0 +1,182 @@
+var Lib = module.exports;
+
+// http://codereview.stackexchange.com/questions/37028/grouping-elements-in-array-by-multiple-properties
+Lib.groupBy = function(array, f)
+{
+    var groups = {};
+    array.forEach(function(o) {
+        var group = JSON.stringify(f(o));
+        groups[group] = groups[group] || [];
+        groups[group].push(o);
+    });
+
+    return Object.keys(groups).map(function(group) {
+        return groups[group];
+    });
+};
+
+function letterToInt(letter) {
+    switch (letter) {
+        case 'B': return 0;
+        case 'V': return 1;
+        case 'A': return 2;
+        default:  return null;
+    }
+}
+
+Lib.compareRecommendationStyle = function(style1, style2) {
+
+    return letterToInt(style1.recommendation_style[4]) - letterToInt(style2.recommendation_style[4]);
+
+};
+
+Lib.experimentDuration = function(exp) {
+
+    if (exp === undefined) {
+
+        return;
+
+    }
+
+    var lastCoin = null;
+
+    for (var i = exp.elements.events.length - 1; i >= 0; i--) {
+        if (exp.elements.events[i].type === 'coin') {
+            lastCoin = exp.elements.events[i];
+            break;
+        }
+    }
+
+    return Lib.timeDifference(exp.elements.events[0].time, lastCoin.time);
+
+};
+
+Lib.max = function(elt1, elt2) {
+
+    if (elt1 === undefined)
+        return elt2;
+
+    if (elt2 === undefined)
+        return elt1;
+
+    return Math.max(elt1,elt2);
+
+};
+
+Lib.min = function(elt1, elt2) {
+
+    if (elt1 === undefined)
+        return elt2;
+
+    if (elt2 === undefined)
+        return elt1;
+
+    return Math.min(elt1,elt2);
+
+};
+
+Lib.timeDifference = function(time1, time2) {
+
+    return new Date(time2).getTime() - new Date(time1).getTime();
+
+};
+
+Lib.timeToString = function(_time) {
+
+    var time = _time / 1000;
+
+    return Math.floor(time / 3600) + 'h' + Math.floor((time % 3600) / 60) + 'm' + Math.floor(time % 60);
+
+};
+
+Lib.makeGroups = function(db) {
+
+    var elements = [];
+
+    for (var i = 0; i < db.experiments.length; i++) {
+
+        if (db.experiments[i].coinCombination.scene_id !== 1 && db.experiments[i].elements.events.length !== 0) {
+
+            elements.push(db.experiments[i]);
+
+        }
+
+    }
+
+    return Lib.groupBy(elements, function(item) {
+        return item.coin_combination_id;//, item.user.rating];
+    });
+
+};
+
+Lib.loadFromFile = function(path) {
+
+    return JSON.parse(require('fs').readFileSync(path, 'utf8'));
+
+};
+
+Lib.toMatlabArray = function(name, array) {
+
+    var str = name + ' = [ ';
+
+    array.forEach(function(elt) { str += ' ' + elt + ' '; });
+
+    str += '];\n';
+
+    return str;
+
+};
+
+// http://stackoverflow.com/questions/3895478/
+Lib.range = function(start, stop, step, computation) {
+
+    if (typeof step === 'function') {
+
+        computation = step;
+        step = 1;
+
+    }
+
+    if (computation === undefined) {
+
+        computation = function(i) { return i; };
+
+    }
+
+    if (step === undefined) {
+
+        step = 1;
+
+    }
+
+    var a = [];
+    while (start < stop) {
+        a.push(computation(start));
+        start += step;
+    }
+    return a;
+};
+
+// Simplified version
+Lib.numberOfInteraction = function(exp) {
+
+    if (exp === undefined) {
+
+        return;
+
+    }
+
+
+    for (var i = exp.elements.events.length - 1; i >= 0; i--) {
+        if (exp.elements.events[i].type === 'coin') {
+            // lastCoin = exp.elements.events[i];
+            break;
+        }
+    }
+
+
+
+
+    return i;
+
+};
diff --git a/analysis/matlab/script.m b/analysis/matlab/script.m
new file mode 100644
index 0000000..b59012f
--- /dev/null
+++ b/analysis/matlab/script.m
@@ -0,0 +1,7 @@
+var;
+plot(X,Y1);
+hold on;
+plot(X, Y2, 'red');
+hold on;
+plot(X, Y3, 'green');
+legend('Without recommendation', 'Worst with recommendation', 'Best with recommendation');
diff --git a/analysis/numberOfInteractionCurve.js b/analysis/numberOfInteractionCurve.js
new file mode 100644
index 0000000..ecc2129
--- /dev/null
+++ b/analysis/numberOfInteractionCurve.js
@@ -0,0 +1,45 @@
+// Shows with and without : time to last coin = f(CoinCombination)
+
+var lib = require('./lib.js');
+
+
+function main(path) {
+
+    var db = lib.loadFromFile(path);
+    var groups = lib.makeGroups(db);
+
+    // Erase groups that are not usable
+    groups = groups.filter(function(elt) {
+
+        // An elt is valid if it contains at least 2 exp, BaseRecommendation included
+        return elt.length > 1 && elt.find(function(e) { return e.recommendation_style[4] === 'B'; }) !== undefined;
+
+    });
+
+    groups.forEach(function(elt) {
+        elt.sort(lib.compareRecommendationStyle);
+    });
+
+    console.log(lib.toMatlabArray('X', lib.range(0, groups.length)));
+
+    console.log(lib.toMatlabArray('Y1', lib.range(0, groups.length, function(i) {
+        return lib.numberOfInteraction(groups[i][0]);
+    })));
+
+    console.log(lib.toMatlabArray('Y2', lib.range(0, groups.length, function(i) {
+        return lib.max(lib.numberOfInteraction(groups[i][1]), lib.numberOfInteraction(groups[i][2]));
+    })));
+
+    console.log(lib.toMatlabArray('Y3', lib.range(0, groups.length, function(i) {
+        return lib.min(lib.numberOfInteraction(groups[i][1]), lib.numberOfInteraction(groups[i][2]));
+    })));
+
+}
+
+if (process.argv.length !== 3) {
+    process.stderr.write('Error : please give me a JSON file to work on\n');
+    process.exit(-1);
+}
+
+main(process.argv[2]);
+
diff --git a/analysis/timeCurve.js b/analysis/timeCurve.js
new file mode 100644
index 0000000..5ef627c
--- /dev/null
+++ b/analysis/timeCurve.js
@@ -0,0 +1,45 @@
+// Shows with and without : time to last coin = f(CoinCombination)
+
+var lib = require('./lib.js');
+
+
+function main(path) {
+
+    var db = lib.loadFromFile(path);
+    var groups = lib.makeGroups(db);
+
+    // Erase groups that are not usable
+    groups = groups.filter(function(elt) {
+
+        // An elt is valid if it contains at least 2 exp, BaseRecommendation included
+        return elt.length > 1 && elt.find(function(e) { return e.recommendation_style[4] === 'B'; }) !== undefined;
+
+    });
+
+    groups.forEach(function(elt) {
+        elt.sort(lib.compareRecommendationStyle);
+    });
+
+    console.log(lib.toMatlabArray('X', lib.range(0, groups.length)));
+
+    console.log(lib.toMatlabArray('Y1', lib.range(0, groups.length, function(i) {
+        return lib.experimentDuration(groups[i][0]);
+    })));
+
+    console.log(lib.toMatlabArray('Y2', lib.range(0, groups.length, function(i) {
+        return lib.max(lib.experimentDuration(groups[i][1]), lib.experimentDuration(groups[i][2]));
+    })));
+
+    console.log(lib.toMatlabArray('Y3', lib.range(0, groups.length, function(i) {
+        return lib.min(lib.experimentDuration(groups[i][1]), lib.experimentDuration(groups[i][2]));
+    })));
+
+}
+
+if (process.argv.length !== 3) {
+    process.stderr.write('Error : please give me a JSON file to work on\n');
+    process.exit(-1);
+}
+
+main(process.argv[2]);
+