Create keepLastValue() target function

[chrismd]

The keepLastValue() target function should change the rendering behavior for each series passed to it such that missing values are converted to the last known value preceding them.

[kraig (kamador)]

This was a good idea. I found a lot of places to use this function.

diff --git a/composer_widgets.js b/composer_widgets.js
index f50997a..cba0c4c 100644
--- a/composer_widgets.js
+++ b/composer_widgets.js
@@ -404,6 +404,7 @@ var TargetsWindow = { //This widget has a lot of state, so an object is appropri
         {text: 'Most Deviant', handler: this.applyFuncToEachWithInput('mostDeviant', "Draw the ___ metrics with the highest standard deviation")},
         {text: 'Standard Deviation', handler: this.applyFuncToEachWithInput('stdev', "Draw the standard deviation for the last _ data points")},
         {text: 'Offset', handler: this.applyFuncToEachWithInput('offset', "Draw the graph with an offset of _")},
+ {text: 'Keep Last Value', handler: this.applyFuncToEach('keepLastValue')},
         {text: 'Remove Outer Call', handler: this.removeOuterCall.createDelegate(this)}
       ]
     });
diff --git a/functions.py b/functions.py
index d18315c..9c0da17 100644
--- a/functions.py
+++ b/functions.py
@@ -93,6 +93,15 @@ def averageSeries(*seriesLists):
   series.pathExpression = name
   return [series]

+def keepLastValue(seriesList):
+ for series in seriesList:
+ series.name = "keepLastValue(%s)" % (series.name)
+ for i,value in enumerate(series):
+ if value is None:
+ value = series[i-1]
+ series[i] = value
+ return seriesList
+
 def asPercent(seriesList1,seriesList2orNumber):
   assert len(seriesList1) == 1, "asPercent series arguments must reference *exactly* 1 series"
   series1 = seriesList1[0]
@@ -264,4 +273,5 @@ SeriesFunctions = {
   'mostDeviant' : mostDeviant,
   'stdev' : stdev,
   'offset' : offset,
+ 'keepLastValue' : keepLastValue,
 }

[kraig (kamador)]

commited in 121

[chrismd (chrismd)]

Thanks for the patch kraig, this does look like a very useful function!