I am trying to figure out how to add a trendline to my google line chart but am failing miserably. Is anyone able to point me in the right direction? I have seen that google do not provide a way to do this on a line chart but have also seen that it is possible to add a new series into the chart to achieve something similar. Here is what I have so far which works great besides not having a trendline. I have tried a few suggestions I found online but none of them made the maths clear to get the trendline to be a straight line:
function drawChartCustomerRevenue_93() {
var revenueChart_93;
var data = new google.visualization.DataTable();
data.addColumn('string', Date);
data.addColumn('number', 'Sales Value');
data.addRow(['Apr 2013', 271176.940000000]);
data.addRow(['May 2013', 419031.540000000]);
data.addRow(['Jun 2013', 429155.540000000]);
data.addRow(['Jul 2013', 443780.400000000]);
data.addRow(['Aug 2013', 320353.540000000]);
data.addRow(['Sep 2013', 310640.910000000]);
data.addRow(['Oct 2013', 252187.700000000]);
data.addRow(['Nov 2013', 301414.560000000]);
data.addRow(['Dec 2013', 224296.850000000]);
data.addRow(['Jan 2014', 291131.140000000]);
data.addRow(['Feb 2014', 354750.680000000]);
data.addRow(['Mar 2014', 312736.710000000]);
var formatter = new google.visualization.NumberFormat({
fractionDigits: 2,
prefix: '£'
});
formatter.format(data, 1);
var chartHeight = 400;
var chartWidth = 500;
var chartOptions = {
trendlines: {
{
color: 'green',
}
},
title: '1: TEST NAME',
isStacked: true,
width: chartWidth,
height: chartHeight,
colors: ['#0000D4'],
hAxis: {
title: 'Sales Value (£)',
slantedText: true,
slantedTextAngle: 45,
textStyle: {
fontSize: 10
},
},
chartArea: {
left: 100,
top: 20,
width: (chartWidth - 10),
height: (chartHeight - 90)
}
};
revenueChart_93 = new google.visualization.LineChart(document.getElementById('CustomerRevenue_93'));
revenueChart_93.draw(data, chartOptions);
};
drawChartCustomerRevenue_93();
EDIT:
I have now attempted to put the code in suggested to me but it still shows no trendline:
function drawChartCustomerRevenue_93() {
var revenueChart_93;
var data = new google.visualization.DataTable();
data.addColumn('date', 'Date');
data.addColumn('number', 'Sales Value');
data.addRow([new Date(2013, 4, 1), 184656.440000000]);
data.addRow([new Date(2013, 5, 1), 420286.250000000]);
data.addRow([new Date(2013, 6, 1), 431562.840000000]);
data.addRow([new Date(2013, 7, 1), 446187.800000000]);
data.addRow([new Date(2013, 8, 1), 320353.540000000]);
data.addRow([new Date(2013, 9, 1), 313364.960000000]);
data.addRow([new Date(2013, 10, 1), 252187.700000000]);
data.addRow([new Date(2013, 11, 1), 303874.560000000]);
data.addRow([new Date(2013, 12, 1), 224296.850000000]);
data.addRow([new Date(2014, 1, 1), 297499.970000000]);
data.addRow([new Date(2014, 2, 1), 354950.680000000]);
data.addRow([new Date(2014, 3, 1), 315529.610000000]);
data.addRow([new Date(2014, 4, 1), 145219.710000000]);
var formatter = new google.visualization.NumberFormat({
fractionDigits: 2,
prefix: '£'
});
formatter.format(data, 1);
var dateFormatter = new google.visualization.NumberFormat({
pattern: 'MMM yyyy'
});
dateFormatter.format(data, 0);
var chartHeight = 320;
var chartWidth = 400;
var chartOptions = {
trendlines: {
0: {
color: 'green'
}
},
title: '1: Test Name',
isStacked: true,
width: chartWidth,
height: chartHeight,
colors: ['#0000D4'],
hAxis: {
title: 'Sales Value (£)',
slantedText: true,
slantedTextAngle: 45,
textStyle: {
fontSize: 10
},
format: 'MMM yyyy',
},
chartArea: {
left: 100,
top: 20,
width: (chartWidth - 8),
height: (chartHeight - 72)
}
};
revenueChart_93 = new google.visualization.LineChart(document.getElementById('CustomerRevenue_93'));
revenueChart_93.draw(data, chartOptions);
};
drawChartCustomerRevenue_93();
First, as @mcgyver5 pointed out, trendlines are not supported for discrete (string-based) axes. Since your data is monthly, you can switch to a Date axis instead of a string axis, which would fix that issue. Also, your trendlines option is not specified correctly.
Here's an example that fixes both issues:
function drawChartCustomerRevenue_93() {
var revenueChart_93;
var data = new google.visualization.DataTable();
data.addColumn('date', 'Date');
data.addColumn('number', 'Sales Value');
data.addRow([new Date(2013, 3, 1), 271176.940000000]);
data.addRow([new Date(2013, 4, 1), 419031.540000000]);
data.addRow([new Date(2013, 5, 1), 429155.540000000]);
data.addRow([new Date(2013, 6, 1), 443780.400000000]);
data.addRow([new Date(2013, 7, 1), 320353.540000000]);
data.addRow([new Date(2013, 8, 1), 310640.910000000]);
data.addRow([new Date(2013, 9, 1), 252187.700000000]);
data.addRow([new Date(2013, 10, 1), 301414.560000000]);
data.addRow([new Date(2013, 11, 1), 224296.850000000]);
data.addRow([new Date(2014, 0, 1), 291131.140000000]);
data.addRow([new Date(2014, 1, 1), 354750.680000000]);
data.addRow([new Date(2014, 2, 1), 312736.710000000]);
var formatter = new google.visualization.NumberFormat({
fractionDigits: 2,
prefix: '£'
});
formatter.format(data, 1);
var dateFormatter = new google.visualization.NumberFormat({
pattern: 'MMM yyyy'
});
dateFormatter.format(data, 0);
var chartHeight = 400;
var chartWidth = 500;
var chartOptions = {
trendlines: {
0: {
color: 'green'
}
},
title: '1: TEST NAME',
isStacked: true,
width: chartWidth,
height: chartHeight,
colors: ['#0000D4'],
hAxis: {
title: 'Sales Value (£)',
slantedText: true,
slantedTextAngle: 45,
textStyle: {
fontSize: 10
},
format: 'MMM yyyy'
},
chartArea: {
left: 100,
top: 20,
width: (chartWidth - 10),
height: (chartHeight - 90)
}
};
revenueChart_93 = new google.visualization.LineChart(document.getElementById('CustomerRevenue_93'));
revenueChart_93.draw(data, chartOptions);
}
see it working here: http://jsfiddle.net/asgallant/j8N48/