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Heatmaps in plotly.js

How to make a D3.js-based heatmap in javascript with a matrix. Seven examples of colored and labeled heatmaps with custom colorscales.

//number of spiral loops

var nspiral = 2;

// angle

var th = numeric.linspace(((-Math.PI) / 13), (2 * Math.PI * nspiral), 1000);

//Empty Value Containers

var xValues = [];
var yValues = [];
var yShift = [];
var finalX = [];
var finalY = [];

//spiral

for(var i = 0; i <th.length; i++){
  var a = 1.120529;
  var b = 0.306349;
  var r = a * Math.exp((-b) * th[i]);
  var xResult = (r * Math.cos(th[i]));
  var yResult = (r * Math.sin(th[i]));
  xValues.push(xResult);
  yValues.push(yResult);
}

function getMaxOfArray(numArray) {
  return Math.max.apply(null, numArray);
};

function getMinOfArray(numArray) {
  return Math.min.apply(null, numArray);
};

//Shift spiral north so that it is centered

var yShift = (1.6 - (getMaxOfArray(yValues) - getMinOfArray(yValues))) / 2;

var spiralTrace = {
  x: xValues.map(function(xi) { return -(xi) + xValues[0]; }),
  y: yValues.map(function(yi) { return yi - yValues[0] + yShift; }),
  type: 'scatter',
  line: {
    color: 'white',
    width: 3
  }
};

//Build the rectangles as a heatmap and specify the edges of the heatmap squares

var phi = (1 + Math.sqrt(5)) / 2;
var xe = [0, 1, (1 + (1 / Math.pow(phi,4))), 1 + (1 / Math.pow(phi,3)), phi];
var ye = [0, (1 / Math.pow(phi,3)), (1 / Math.pow(phi,3)) + (1 / Math.pow(phi,4)), (1 / Math.pow(phi,2)), 1];

var zValues = [
  [13, 3, 3, 5],
  [13, 2, 1, 5],
  [13, 10, 11, 12],
  [13, 8, 8, 8]
];

var hm = {
  x: xe,
  y: ye.map(function(yi) { return yi + yShift; }),
  z: zValues,
  type: 'heatmap',
  colorscale: 'Viridis'
};

var axisTemplate = {
  range: [0, 1.6],
  autorange: false,
  showgrid: false,
  zeroline: false,
  linecolor: 'black',
  showticklabels: false,
  ticks: ''
};

var data = [spiralTrace, hm];

var layout = {
  title: 'Heatmap with Unequal Block Sizes',
  margin: {
    t: 200,
    r: 200,
    b: 200,
    l: 200
  },
  xaxis: axisTemplate,
  yaxis: axisTemplate,
  showlegend: false,
  with: 700,
  height: 700,
  autosize: false
};

Plotly.newPlot('myDiv', data, layout);
var data = [
  {
    z: [[1, 20, 30], [20, 1, 60], [30, 60, 1]],
    type: 'heatmap'
  }
];

Plotly.newPlot('myDiv', data);
var xValues = ['A', 'B', 'C', 'D', 'E'];

var yValues = ['W', 'X', 'Y', 'Z'];

var zValues = [
  [0.00, 0.00, 0.75, 0.75, 0.00],
  [0.00, 0.00, 0.75, 0.75, 0.00],
  [0.75, 0.75, 0.75, 0.75, 0.75],
  [0.00, 0.00, 0.00, 0.75, 0.00]
];

var colorscaleValue = [
  [0, '#3D9970'],
  [1, '#001f3f']
];

var data = [{
  x: xValues,
  y: yValues,
  z: zValues,
  type: 'heatmap',
  colorscale: colorscaleValue,
  showscale: false
}];

var layout = {
  title: 'Annotated Heatmap',
  annotations: [],
  xaxis: {
    ticks: '',
    side: 'top'
  },
  yaxis: {
    ticks: '',
    ticksuffix: ' ',
    width: 700,
    height: 700,
    autosize: false
  }
};

for ( var i = 0; i < yValues.length; i++ ) {
  for ( var j = 0; j < xValues.length; j++ ) {
    var currentValue = zValues[i][j];
    if (currentValue != 0.0) {
      var textColor = 'white';
    }else{
      var textColor = 'black';
    }
    var result = {
      xref: 'x1',
      yref: 'y1',
      x: xValues[j],
      y: yValues[i],
      text: zValues[i][j],
      font: {
        family: 'Arial',
        size: 12,
        color: 'rgb(50, 171, 96)'
      },
      showarrow: false,
      font: {
        color: textColor
      }
    };
    layout.annotations.push(result);
  }
}

Plotly.newPlot('myDiv', data, layout);
var data = [
  {
    z: [[1, 20, 30, 50, 1], [20, 1, 60, 80, 30], [30, 60, 1, -10, 20]],
    x: ['Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday'],
    y: ['Morning', 'Afternoon', 'Evening'],
    type: 'heatmap'
  }
];

Plotly.newPlot('myDiv', data);
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