working example

.gitignore

@@ -0,0 +1 @@
+.npmignore

examples/simple/example1-bundle.js

@@ -644,7 +644,9 @@ EventEmitter.prototype.listeners = function(type) {
 
 require.define("/package.json",function(require,module,exports,__dirname,__filename,process){module.exports = {"main":"index.js"}});
 
-require.define("/index.js",function(require,module,exports,__dirname,__filename,process){var series = function() {
+require.define("/index.js",function(require,module,exports,__dirname,__filename,process){var lib = require('./lib');
+
+var series = function() {
     var args = [].slice.call(arguments,0);
     for (var i = 0;i < args.length; i++) {
         this.sources.push(args[i]);
@@ -654,10 +656,28 @@ var to = function(el) {
     this.canvas = el;
     this.ctx = el.getContext('2d');
     this.ctx.font = '20pt Arial';
+    this.ctx.fillStyle = '#000000';
     this.sources.forEach(function(source) {
         var put = function(data) {
+            if (source.count === undefined)
+                source.count = 0;
+            source.count++;
+            if (source.dataset === undefined)
+                source.dataset = [];
+            source.dataset.push(data); 
+
+            var windowsize = source.windowsize || 10;
+            var datatodisplay = lib.cropData(source.dataset,windowsize);
+            var x = lib.getStartX(datatodisplay.length,windowsize,this.canvas.width); 
+            var spacing = lib.getSpacing(windowsize,this.canvas.width);
+
             this.ctx.clearRect(0,0,this.canvas.width,this.canvas.height);    
-            this.ctx.fillText(data,0,100);
+            datatodisplay.forEach(function(data,idx) {
+                this.ctx.beginPath();
+                this.ctx.arc(x + (idx*spacing), this.canvas.height - data, 5, 0, Math.PI*2, false);
+                this.ctx.stroke();
+            },this);
+//            this.ctx.fillText(data,0,100);
         };
         source.on('data',put.bind(this));
     },this);
@@ -669,9 +689,11 @@ var todiv = function(el) {
             this.div.innerHTML = data;
         };
         source.on('data',put.bind(this));
-    });
+    },this);
 };
 var chart = function() {
+    this.buffer = document.createElement('canvas');
+    this.bufferctx = this.buffer.getContext('2d');
     this.sources = [];
     this.to = to;
     this.toDiv = todiv;
@@ -680,6 +702,26 @@ var chart = function() {
 exports.Chart = chart;
 });
 
+require.define("/lib/index.js",function(require,module,exports,__dirname,__filename,process){exports.cropData = function(list,windowsize) {
+    if (list.length < windowsize)
+        return list
+    else return list.slice(list.length - windowsize)
+};
+var getSpacing = function(windowsize,canvaswidth) {
+    return Math.floor(canvaswidth / (windowsize-1));
+}
+exports.getSpacing = getSpacing;
+exports.getStartX = function(length,windowsize,canvaswidth) {
+    var x = undefined;
+    var spacing = getSpacing(windowsize,canvaswidth);
+    if (length <= windowsize) {
+        x = canvaswidth - (spacing * (length-1));
+    } else 
+        x = 0;
+    return x;
+}
+});
+
 require.define("/examples/simple/example1.js",function(require,module,exports,__dirname,__filename,process){var ee = require('events').EventEmitter;
 var nodechart = require('../../index.js');
 var datasource = new ee;

index.js

@@ -1,3 +1,5 @@
+var lib = require('./lib');
+
 var series = function() {
     var args = [].slice.call(arguments,0);
     for (var i = 0;i < args.length; i++) {
@@ -11,8 +13,25 @@ var to = function(el) {
     this.ctx.fillStyle = '#000000';
     this.sources.forEach(function(source) {
         var put = function(data) {
+            if (source.count === undefined)
+                source.count = 0;
+            source.count++;
+            if (source.dataset === undefined)
+                source.dataset = [];
+            source.dataset.push(data); 
+
+            var windowsize = source.windowsize || 10;
+            var datatodisplay = lib.cropData(source.dataset,windowsize);
+            var x = lib.getStartX(datatodisplay.length,windowsize,this.canvas.width); 
+            var spacing = lib.getSpacing(windowsize,this.canvas.width);
+
             this.ctx.clearRect(0,0,this.canvas.width,this.canvas.height);    
-            this.ctx.fillText(data,0,100);
+            datatodisplay.forEach(function(data,idx) {
+                this.ctx.beginPath();
+                this.ctx.arc(x + (idx*spacing), this.canvas.height - data, 5, 0, Math.PI*2, false);
+                this.ctx.stroke();
+            },this);
+//            this.ctx.fillText(data,0,100);
         };
         source.on('data',put.bind(this));
     },this);
@@ -27,6 +46,8 @@ var todiv = function(el) {
     },this);
 };
 var chart = function() {
+    this.buffer = document.createElement('canvas');
+    this.bufferctx = this.buffer.getContext('2d');
     this.sources = [];
     this.to = to;
     this.toDiv = todiv;

lib/index.js

@@ -0,0 +1,18 @@
+exports.cropData = function(list,windowsize) {
+    if (list.length < windowsize)
+        return list
+    else return list.slice(list.length - windowsize)
+};
+var getSpacing = function(windowsize,canvaswidth) {
+    return Math.floor(canvaswidth / (windowsize-1));
+}
+exports.getSpacing = getSpacing;
+exports.getStartX = function(length,windowsize,canvaswidth) {
+    var x = undefined;
+    var spacing = getSpacing(windowsize,canvaswidth);
+    if (length <= windowsize) {
+        x = canvaswidth - (spacing * (length-1));
+    } else 
+        x = 0;
+    return x;
+}

package.json

@@ -15,6 +15,7 @@
   },
   "main": "index.js",
   "dependencies": {
+    "hat" :""
   },
   "devDependencies": {}
 }

test/test.js

@@ -0,0 +1,31 @@
+var lib = require('../lib');
+var test = require('tap').test;
+
+test('cropdata',function(t) {
+    t.plan(3);
+    var x = [1,2,3,4,5,6];
+    var a = lib.cropData(x,2);
+    t.deepEqual(a,[5,6]);
+    var b = lib.cropData(x,6);
+    t.deepEqual(b,[1,2,3,4,5,6]);
+    var c = lib.cropData(x,7);
+    t.deepEqual(c,[1,2,3,4,5,6]);
+});
+
+test('spacing',function(t) {
+    t.plan(1);
+    var spacing = lib.getSpacing(5,200);
+    t.equal(spacing,50);
+});
+test('startx',function(t) {
+    t.plan(4);
+    var spacing = lib.getSpacing(5,200);
+    var startx = lib.getStartX(2,5,200);
+    t.equal(startx,150);
+    startx = lib.getStartX(1,5,200);
+    t.equal(startx,200);
+    startx = lib.getStartX(4,5,200);
+    t.equal(startx,50);
+    startx = lib.getStartX(5,5,200);
+    t.equal(startx,0);
+});