Add arrow heads on Google Line Chart - google-visualization

I've been working on a Google Line chart project
oChart = new google.visualization.LineChart(document.getElementById('main'));
drawChart();
setInterval(drawChart, 800);
var rowIndex = 0;
function drawChart() {
if (rowIndex < oRawData.length) {
data.addRow(oRawData[rowIndex++]);
oChart.draw(data, oAltered);
}
}
Is there a way to add an arrow head when you call the draw() function in google chart? I can't seem to any in its documentation.

Related

Horizontal line syncing across multiple charts when hovering with Chart.js in Typescript-react

When hovering over anywhere inside of the chart, I currently am drawing a horizontal line all the way across the chart. I want the ability to be able to sync that across multiple charts on the same page. I am currently doing it with the following code-snippet in my options. I would like for whatever point is being hovered in one chart creating a line, to also have the same hover line across multiple charts. You can see in the image I would be hovering right above the 400 ms mark.
const options= {
onHover:(context:any) => {
const yAxis = context.y;
context.chart.clear();
const ctx = context.chart.ctx;
ctx.beginPath();
ctx.moveTo(45, yAxis);
ctx.lineTo(10000, yAxis);
ctx.lineWidth = 1;
ctx.strokeStyle = 'gray';
ctx.stroke();
}
}
I was able to solve this and even make it so it could apply to only certain charts on the page, and even have multiple different groups of synced up charts. The afterEvent sets the X value I want, and the className is set to tell which report group I would like to apply this hover to. If it detects it mousedOut, it sets the x value to 0 and therefore hides it. (Note that I ended up going with a vertical line instead of a horizontal, but the same thing could be done by flipping the x and y values and grabbing e.event.y).
const [xVal, setXVal] = useState(0)
const [currentClassName, setCurrentClassName] = useState('')
const verticalHover = {
id:"verticalHover",
afterEvent: (chart:any, e:any) => {
if(e.event.type === 'mousemove') {
setXVal(e.event.x)
setCurrentClassName(chart.canvas.className)
}
else if(e.event.type === 'mouseout') {
setXVal(0)
setCurrentClassName(chart.canvas.className)
}
},
afterDraw: (chartInstance: any) => {
if(xVal !==0 && chartInstance.canvas.className ===currentClassName){
const ctx = chartInstance.ctx;
ctx.strokeStyle = "#6f6f6f";
ctx.lineWidth = 2;
ctx.beginPath();
//Hardcoded yValues for now
ctx.moveTo(xVal, 40);
ctx.lineTo(xVal,265);
ctx.stroke();
}
}
}
Chart.register(verticalHover);

Chartjs unexpected visual animation effect when adding data

I have a long array with data that I slice with Javascript in order to display data of different date ranges in my chart. This way the backend only needs to get the data once, and I can the just slice it on the client side.
// All data
var allLabels = [
// data here
];
var allData = [
// data here
];
Then I do:
var labelsCount = allLabels.length;
var dataCount = allData.length;
var updatedLabels;
var updatedData;
if($date_range === 'last_7_days')
{
updatedLabels = allLabels.slice(labelsCount - 7);
updatedData = allData.slice(labelsCount - 7);
}
if($date_range === 'last_30_days')
{
updatedLabels = allLabels.slice(labelsCount - 30);
updatedData = allData.slice(labelsCount - 30);
}
scoreChart.data.labels = updatedLabels;
scoreChart.data.datasets[0].data = updatedData;
scoreChart.update({
duration: 1000,
easing: 'easeInOutExpo'
});
This all works as expected. When switching from 30 to 7 days the points on the right of the 7 days disappear, and the graph scales and grows nicely to the new 7 days x-axis.
The other way around, when you have the graph of 7 days and then switch to 30, produces an ugly visual effect where the first point of the graph sticks to the side, overlaps the new data points and then animates.
After the animation the graph looks as expected, it's just the animation that's ugly. It's a little tricky to explain so hopefully the screenshots help. Green arrows indicate the animation direction. I've set the animation duration to 10s so I can take this screenshot, the red circle highlights the point that starts on the right of the graph and then animates to the left.
I've also tried adding this:
scoreChart.data.labels.pop();
scoreChart.data.datasets[0].data.pop();
scoreChart.update();
and this:
scoreChart.data.labels = [];
scoreChart.data.datasets[0].data = [];
scoreChart.update();
Before the line scoreChart.data.labels = updatedLabels; but that gives the same result.
Another thing I can do is only update the labels. The result is that the chart just zooms on the timeline when changing date ranges, without the nice animation as they have in the example.
You could try to first remove all labels and the data when switching to 'last_30_days'.
if($date_range === 'last_30_days')
{
scoreChart.data.labels = [];
scoreChart.data.datasets[0].data = [];
scoreChart.update({
duration: 500,
easing: 'easeInOutExpo'
});
updatedLabels = allLabels.slice(labelsCount - 30);
updatedData = allData.slice(labelsCount - 30);
}

Change bar color depending on value

I'm using chart-js/ng2-charts for an angular 2 app.
I can display a bar graph, but at the moment, all the bars are the same color. I'd like to have a different color depending on the value.
Can that be done?
After you create your chart, you can use the following function to loop through the dataset and change the color depending on the data value.
In this example, if the value is above a 50, the color changes to red.
var colorChangeValue = 50; //set this to whatever is the deciding color change value
var dataset = myChart.data.datasets[0];
for (var i = 0; i < dataset.data.length; i++) {
if (dataset.data[i] > colorChangeValue) {
dataset.backgroundColor[i] = chartColors.red;
}
}
myChart.update();
JSFiddle Demo: https://jsfiddle.net/6d0jsyxu/1/

Removing body (balls) from physics engine

I've been trying to remove elements (balls) that have been added to the Physics engine, but I can't find a way to do it.
This is the code I'm using to add the molecules to the Physics Engine:
var numBodies = 15;
function _addMolecules() {
for (var i = 0; i < numBodies; i++) {
var radius = 20;
var molecule = new Surface({
size: [radius * 2, radius * 2],
properties: {
borderRadius: radius + 'px',
backgroundColor: '#'+(0x1000000+(Math.random())*0xffffff).toString(16).substr(1,6)
}
});
molecule.body = new Circle({
radius: radius,
mass: 2
});
this.pe.addBody(molecule.body);
this.molecules.push(molecule);
this.moleculeBodies.push(molecule.body);
molecule.state = new Modifier({origin: [0.5, 0.5]});
//** This is where I'm applying the gravity to the balls and also where I'm checking the position of each ball
molecule.state.transformFrom(addBodyTransform.bind(molecule.body));
this._add(molecule.state).add(molecule);
}
}
and on the addBodyTransform function I'm adding the gravity to the balls and checking their position, and for any that are outside the top part of the viewport I want to remove it completely (I'm only using walls on the left, right and bottom edges of the viewport).
function addBodyTransform() {
var pos;
for (var i = 0; i < thisObj.moleculeBodies.length; i++) {
pos = thisObj.moleculeBodies[i].getPosition();
if(pos[1]<(-windowY/2)){
//I tried this but it doesn't work
thisObj.pe.removeBody(thisObj.moleculeBodies[i]);
thisObj.moleculeBodies[i].render = function(){ return null; };
}
}
thisObj.gravity.applyForce(this);
return this.getTransform();
}
It doesn't work. I tried a couple of other things, but no luck. Whereas changing the position of the balls on the function above worked fine:
thisObj.moleculeBodies[i].setPosition([0, 0]);
Does anybody have any idea how to remove a body (a circle in this case)?
P.S.: thisObj is the variable I'm assign the "this" object to in the constructor function and thisObj.pe is the instance of the PhysicsEngine(). Hope that makes sense.
After some investigation, using the unminified source code and trying out different things, I realised that there was something weird going on in the library.
Having a look at the repository, I found out that the function _getBoundAgent is being used before it is defined, which matched with the error I was getting (you can check it here: https://travis-ci.org/Famous/physics). So it looks like it is a bug in the Famo.us source-code. Hopefully it will be fixed in the next release.
For the time being, I had to create a hack, which is basically detaching all agents (as well as gravity) from the balls that go outside the viewport and setting their (fixed) position far outside the viewport (about -2000px in both directions).
I know it is not the best approach (a dirty one indeed), but if you have the same problem and want to use it until they release a fix for that, here is what I did:
function addBodyTransform() {
var pos = this.body.getPosition();
//Check if balls are inside viewport
if(pos[1]<(-(windowY/2)-100)){
if(!this.removed){
//flagging ball so the code below is executed only once
this.removed = true;
//Set position (x and y) of the ball 2000px outside the viewport
this.body.setPosition([(-(windowX/2)-2000), (-(windowY/2)-2000)]);
}
return this.body.getTransform();
}else{
//Add gravity only if inside viewport
thisObj.gravity.applyForce(this.body);
return this.body.getTransform();
}
}
and on the _addMolecules function, I'm adding a "molecule.removed = false":
function _addMolecules() {
for (var i = 0; i < numBodies; i++) {
...
molecule.state = new Modifier({origin: [0.5, 0.5]});
//Flagging molecule so I know which ones are removed
molecule.removed = false;
molecule.state.transformFrom(addBodyTransform.bind(molecule));
this._add(molecule.state).add(molecule);
}
}
Again, I know it is not the best approach and I will be keen in hearing from someone with a better solution. :)

RaphaelJS hide shape onmouseout

I've created 4 rects using for loop. If you hover on any of these rects a rect will be displayed alongside. But the problem is that newly displayed rect doesn't hide on mouse out. What is wrong with my code?
JS Fiddle
window.onload = function() {
var paper = Raphael(0, 0, 640, 540);
function aa(h1,h2){
var showbox = paper.rect(h1+300,h2,100,100);
}
function ab(){
showbox.hide();
}
for (i = 0; i < 2; i++) {
for (j = 0; j < 2; j++) {
(function(i, j) {
var boxes = paper.rect(0 + (j * 100), 0 + (i * 100), 100, 100).attr({
fill: '#303030',
stroke: 'white'
});
boxes.node.onmouseover = function() {
var h1 = boxes.getBBox().x;
var h2 = boxes.getBBox().y;
aa(h1,h2);
};
boxes.node.onmouseout = function() {
ab();
};
})(i, j);
}
}
You've got javascript scope problems (plus two other smaller problems, see below).
The variable showbox is defined within function aa. So your onmouseout function can't see it. Get Firebug or your browser's equivalent up and you'll see a stack of showbox is not defined errors.
Tip: When working with Raphael, I usually create an object or array that contains all my created objects, keyed for easy access and scoped above all my Raphael-related functions so all of them can access it (see jsfiddle example below).
How to access your Raphael objects is a piece of application design you need to decide on early on, else you'll need to do lots of refactoring further down the line (been there, it hurts!).
Here's an adapted version of your code that works:
jsfiddle
Edit: I added comments explaining each change.
It also fixes two other problems:
(In the jsfiddle code) No such attr as display: none; in Raphael, try .attr({opacity:0}) or .hide()...
...BUT... don't! Your mouseover event creates rectangles, your mouseout event... hides them...? You're going to have an ever-growing stack of invisible rectangles that could eventually crash someone's browser. Either show, then hide, or create, then remove - don't create then hide!
The mouseover / mouseout events themselves are actually fine! :-)