Add trendline calculation

This commit is contained in:
Jelte Fennema 2014-07-10 22:53:43 +02:00
parent d5cf1410ed
commit 3c7398d0b6

View File

@ -35,6 +35,13 @@ class Morris.Line extends Morris.Grid
xLabelFormat: null
xLabelMargin: 24
hideHover: false
trendLine: false
trendLineWidth: 2
trendLineColors: [
'#689bc3'
'#a2b3bf'
'#64b764'
]
# Do any size-related calculations
#
@ -184,6 +191,10 @@ class Morris.Line extends Morris.Grid
drawSeries: ->
@seriesPoints = []
for i in [@options.ykeys.length-1..0]
if @options.trendLine isnt false and
@options.trendLine is true or @options.trendLine[i] is true
@_drawTrendLine i
@_drawLineFor i
for i in [@options.ykeys.length-1..0]
@_drawPointFor i
@ -201,6 +212,40 @@ class Morris.Line extends Morris.Grid
if path isnt null
@drawLinePath path, @colorFor(null, index, 'line'), index
_drawTrendLine: (index) ->
# Least squares fitting for y = x * a + b
sum_x = 0
sum_y = 0
sum_xx = 0
sum_xy = 0
datapoints = 0
for val in @data
x = val.x
y = val.y[index]
if y is undefined
continue
datapoints += 1
sum_x += x
sum_y += y
sum_xx += x * x
sum_xy += x * y
a = (datapoints*sum_xy - sum_x*sum_y) / (datapoints*sum_xx - sum_x*sum_x)
b = (sum_y / datapoints) - ((a * sum_x) / datapoints)
data = [{}, {}]
data[0].x = @transX(@data[0].x)
data[0].y = @transY(@data[0].x * a + b)
data[1].x = @transX(@data[@data.length - 1].x)
data[1].y = @transY(@data[@data.length - 1].x * a + b)
path = Morris.Line.createPath data, false, @bottom
path = @raphael.path(path)
.attr('stroke', @colorFor(null, index, 'trendLine'))
.attr('stroke-width', @options.trendLineWidth)
# create a path for a data series
#
# @private
@ -266,8 +311,10 @@ class Morris.Line extends Morris.Grid
@options.lineColors.call(@, row, sidx, type)
else if type is 'point'
@options.pointFillColors[sidx % @options.pointFillColors.length] || @options.lineColors[sidx % @options.lineColors.length]
else
else if type is 'line'
@options.lineColors[sidx % @options.lineColors.length]
else
@options.trendLineColors[sidx % @options.trendLineColors.length]
drawXAxisLabel: (xPos, yPos, text) ->
@raphael.text(xPos, yPos, text)