Adding data scaling to chart

deepakjois · Feb 17, 2010 · 374145c · 374145c
1 parent d842988
commit 374145c
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Showing 5 changed files with 42 additions and 6 deletions.
diff --git a/Graphics/GChart.hs b/Graphics/GChart.hs
@@ -69,6 +69,7 @@ module Graphics.GChart (
    setChartTitleWithColorAndFontSize,
    setDataEncoding                  ,
    addChartData                     ,
+   addDataScale                     ,
    addChartDataXY                   ,
    setColors                        ,
    addColor                         ,
@@ -239,6 +240,12 @@ setDataEncoding = set
 addChartData :: ChartDataEncodable a => [a] -> ChartM ()
 addChartData = addDataToChart
 
+
+-- | Add a scale to chart.If more than one scale is added, it applies
+-- the scale in order to each data series
+addDataScale :: DataScale -> ChartM ()
+addDataScale = addScaleToChart
+
 -- | Works like 'addChartData', but for XY datasets for line XY chart etc
 addChartDataXY :: ChartDataEncodable a => [(a,a)] -> ChartM ()
 addChartDataXY series = do addDataToChart xseries

diff --git a/Graphics/GChart/ChartItems.hs b/Graphics/GChart/ChartItems.hs
@@ -2,6 +2,7 @@
 module Graphics.GChart.ChartItems (
   getChartDataFromChartM,
   addDataToChart,
+  addScaleToChart,
   addColorToChart,
   addFillToChart,
   addAxisToChart,
@@ -33,6 +34,13 @@ addDataToChart d = do c <- get
                         Just cd -> set $ addEncodedChartData d cd
                         _       -> error "Please set data encoding before adding data"
 
+addScaleToChart scale = do c <- get
+                           let old = chartDataScales c
+                           case old of
+                             Just (CDS cds) -> set $ CDS $ cds ++ [scale]
+                             Nothing -> set $ CDS [scale]
+
+
 addColorToChart color = do chart <- get
                            let (ChartColors old) = fromMaybe (ChartColors []) $ chartColors chart
                                new = ChartColors $ old ++ [color]
@@ -80,6 +88,7 @@ encodeMaybe (Just x)  = encode x
 getParams chart =  filter (/= ("","")) $ concat [encode $ chartType chart,
                                                  encodeMaybe $ chartSize chart,
                                                  encodeMaybe $ chartData chart,
+                                                 encodeMaybe $ chartDataScales chart,
                                                  encodeMaybe $ chartTitle   chart,
                                                  encodeMaybe $ chartColors  chart,
                                                  encodeMaybe $ chartFills   chart,

diff --git a/Graphics/GChart/ChartItems/Data.hs b/Graphics/GChart/ChartItems/Data.hs
@@ -5,6 +5,8 @@ import Graphics.GChart.ChartItems.Util
 
 import Graphics.GChart.DataEncoding
 
+import Data.List(intercalate)
+
 -- Chart Data
 instance ChartItem ChartData where
     set cData = updateChart $ \chart -> chart { chartData = Just cData }
@@ -14,6 +16,11 @@ instance ChartItem ChartData where
                               encodeData (Text d)     = encodeText d
                               encodeData (Extended d) = encodeExtended d
 
+instance ChartItem ChartDataScales where
+    set scales = updateChart $ \chart -> chart { chartDataScales = Just scales }
+
+    encode (CDS scales) = asList ("chds", intercalate "," $ map (\(min,max) -> showFloat min ++ "," ++ showFloat max) scales)
+
 instance ChartDataEncodable Int where
     addEncodedChartData d cd@(Simple old) = Simple $ old ++ [d]
     addEncodedChartData d cd@(Extended old) = Extended $ old ++ [d]
@@ -23,7 +30,6 @@ instance ChartDataEncodable Float where
     addEncodedChartData d cd@(Text old) = Text $ old ++ [d]
     addEncodedChartData d _             = error "Invalid type for specified encoding. Use int data"
 
-
 instance ChartItem QREncoding where
     set qrEnc = updateChart $ \chart -> chart { qrEncoding = Just qrEnc }
 
@@ -36,4 +42,4 @@ instance ChartItem QREncoding where
 instance ChartItem ChartLabelData where
     set chld = updateChart $ \chart -> chart { chartLabelData = Just chld }
 
-    encode (QRLabelData ec m) = asList ("chld", concat [show ec, "|", show m])
+    encode (QRLabelData ec m) = asList ("chld", concat [show ec, "|", show m])
diff --git a/Graphics/GChart/Types.hs b/Graphics/GChart/Types.hs
@@ -18,8 +18,6 @@ Some chart types are not supported yet:
 
 Some parameters are not supported yet:
 
-- Chart Data Scaling <http://code.google.com/apis/chart/docs/data_formats.html#data_scaling>
-
 - Text and Data Value Markers <http://code.google.com/apis/chart/docs/chart_params.html#gcharts_data_point_labels>
 
 - Bar chart zero line <http://code.google.com/apis/chart/docs/gallery/bar_charts.html#chp>
@@ -55,7 +53,7 @@ module Graphics.GChart.Types (
   ChartColors(..), Color,
 
   -- ** Chart Data
-  ChartData(..),
+  ChartData(..), ChartDataScales(..), DataScale(..),
 
   -- ** Chart Legend Text and Style
   ChartLegend(..), LegendPosition(..),
@@ -146,8 +144,14 @@ data ChartTitle =
     , titleFontSize :: Maybe FontSize -- ^ Title Font Size
     } deriving Show
 
+-- | Data scaling expressed as (@series_min@,@series_max@). Applies to text encoding only
+type DataScale = (Float,Float)
+
+-- | List of Data scaling values
+data ChartDataScales = CDS [DataScale] deriving Show
+
 -- | Chart data along with encoding. XY data for is encoded a pair of
--- | consecutive data sets
+-- consecutive data sets
 data ChartData
   = Simple [[Int]]   -- ^ lets you specify integer values from 0-61, inclusive
   | Text [[Float]]   -- ^ supports floating point numbers from 0-100, inclusive
@@ -451,6 +455,7 @@ data Chart =
       chartSize    :: Maybe ChartSize
     , chartType    :: ChartType
     , chartData    :: Maybe ChartData
+    , chartDataScales :: Maybe ChartDataScales
     , chartTitle   :: Maybe ChartTitle
     , chartColors  :: Maybe ChartColors
     , chartFills   :: Maybe ChartFills
@@ -498,6 +503,7 @@ defaultChart =
     Chart { chartSize  = Nothing,
             chartType  = Line,
             chartData  = Nothing,
+            chartDataScales = Nothing,
             chartTitle = Nothing,
             chartColors = Nothing,
             chartFills = Nothing,

diff --git a/examples/Examples.hs b/examples/Examples.hs
@@ -139,6 +139,14 @@ qrCodeChart = getChartUrl $ do setChartType QRCode
                                setQREncoding UTF8
                                setQRErrorCorrection L'
 
+barGraphWithShiftedZeroLine = getChartUrl $ do setChartType BarVerticalGrouped
+                                               setChartSize 320 200
+                                               setDataEncoding text
+                                               addChartData ([30,-60,50,140,80,-90]::[Float])
+                                               addDataScale (-80,140)
+                                               addAxis $ makeAxis { axisType = AxisLeft,
+                                                                    axisRange =  Just $ Range (-80,140) Nothing}
+
 blanks x = replicate x ""
 
 dataSeries1 :: [Int]