-----------------------------------------------------------------------------
             
lineChart :: Picture
lineChart = 
    pictures [ color bgColor $ plotChartBackground xAxis yAxis
             , color gridColor $ plotGrid xAxis yAxis (0, 0.125)
             , plotAxes xAxis yAxis
             , plotAxisScales xAxis yAxis (2, 0.5)
             , line 1 pointColor
             , line 1.5 pointColor'
             , line 3 pointColor''
             ]
    where xAxis     = autoScaleAxis Linear chartW xs
          yAxis     = fixedScaleAxis Linear chartH 0 1
          xs        = [-6,-5.75..6]
          ys        = [sigmoid x | x <- xs]
          pts x     = zip xs (map ((+(0.5 - sigmoid 0 / x)) . (/x)) ys)
          line x c  = color c $ plotLineChart xAxis yAxis (pts x)
          sigmoid x = 1.0 / (1 + exp (-x))
          
          
-----------------------------------------------------------------------------
lineChart :: Picture
lineChart = 
    pictures [ color bgColor $ plotChartBackground xAxis yAxis
             , color gridColor $ plotGrid xAxis yAxis (0, 0.125)
             , plotAxes xAxis yAxis
             , plotAxisScales xAxis yAxis (2, 0.5)
             , line 1 pointColor
             , line 1.5 pointColor'
             , line 3 pointColor''
             ]
    where xAxis     = autoScaleAxis Linear chartW xs
          yAxis     = fixedScaleAxis Linear chartH 0 1
          xs        = [-6,-5.75..6]
          ys        = [sigmoid x | x <- xs]
          pts x     = zip xs (map ((+(0.5 - sigmoid 0 / x)) . (/x)) ys)
          line x c  = color c $ plotLineChart xAxis yAxis (pts x)
          sigmoid x = 1.0 / (1 + exp (-x))
          
          
-----------------------------------------------------------------------------
lineChart = 
    pictures [ color bgColor $ plotChartBackground xAxis yAxis
             , color gridColor $ plotGrid xAxis yAxis (0, 0.125)
             , plotAxes xAxis yAxis
             , plotAxisScales xAxis yAxis (2, 0.5)
             , line 1 pointColor
             , line 1.5 pointColor'
             , line 3 pointColor''
             ]
    where xAxis     = autoScaleAxis Linear chartW xs
          yAxis     = fixedScaleAxis Linear chartH 0 1
          xs        = [-6,-5.75..6]
          ys        = [sigmoid x | x <- xs]
          pts x     = zip xs (map ((+(0.5 - sigmoid 0 / x)) . (/x)) ys)
          line x c  = color c $ plotLineChart xAxis yAxis (pts x)
          sigmoid x = 1.0 / (1 + exp (-x))
          
          
-----------------------------------------------------------------------------