Spotfire: How to increment variables to build scoring mechanism? - spotfire

Question

I'm trying to figure out how I could use variables in Spotfire (online version) to build a scoring mechanism and populate a calculated column with the final result.
I have a couple of values stored in columns that I would use to evaluate and attribute a score like this:
if column1<10 then segment1 = segment1 + 1
if column1>10 then segment2 = segment2+1
...ETC...
In the end each "segment" should have a score and I would like to simply display the name of the segment that has the highest score.
Ex:
Segment1 has a final value of 10
Segment2 has a final value of 22
Segment3 has a final value of 122
I would display Segment3 as value for the calculated column
Using only "IF" would lead me to a complicated IF structure so I'm more looking for something that looks more like a script.
Is there a way to achieve this with Spotfire?
Thanks
Laurent

Answer 1

To cycle through the data rows and calculate a running score, you can use an IronPython script. The script below is reading the numeric data from Col1 and Col2 of a data table named "Data Table". It calculates a score value for each row and writes it to a tab delimited text string. When done, it adds it to the Spotfire table using the Add Columns function. Note, the existing data needs to have a unique identifier. If not, the RowId() function can be used to create a calculated column for a unique row id.
from Spotfire.Dxp.Data import *
from System.IO import StringReader, StreamReader, StreamWriter, MemoryStream, SeekOrigin
from Spotfire.Dxp.Data.Import import *
from System import Array
def add_column(table, text, col_name):
# read the text data into memory
mem_stream = MemoryStream()
writer = StreamWriter(mem_stream)
writer.Write(text)
writer.Flush()
mem_stream.Seek(0, SeekOrigin.Begin)
# define the structure of the text data
settings = TextDataReaderSettings()
settings.Separator = "\t"
settings.SetDataType(0, DataType.Integer)
settings.SetColumnName(0, 'ID')
settings.SetDataType(1, DataType.Real)
settings.SetColumnName(1, col_name)
# create a data source from the in memory text data
data = TextFileDataSource(mem_stream, settings)
# define the relationship between the existing table (left) and the new data (right)
leftColumnSignature = DataColumnSignature("Store ID", DataType.Integer)
rightColumnSignature = DataColumnSignature("ID", DataType.Integer)
columnMap = {leftColumnSignature:rightColumnSignature}
ignoredColumns = []
columnSettings = AddColumnsSettings(columnMap, JoinType.LeftOuterJoin, ignoredColumns)
# now add the column(s)
table.AddColumns(data, columnSettings)
#get the data table
table=Document.Data.Tables["Data Table"]
#place data cursor on a specific column
cursorCol1 = DataValueCursor.CreateFormatted(table.Columns["Col1"])
cursorCol2 = DataValueCursor.CreateFormatted(table.Columns["Col2"])
cursorColId = DataValueCursor.CreateFormatted(table.Columns["ID"])
cursorsList = Array[DataValueCursor]([cursorCol1, cursorCol2, cursorColId])
text = ""
rowsToInclude = IndexSet(table.RowCount,True)
#iterate through table column rows to retrieve the values
for row in table.GetRows(rowsToInclude, cursorsList):
score = 0
# get the current values from the cursors
col1Val = cursorCol1.CurrentDataValue.ValidValue
col2Val = cursorCol2.CurrentDataValue.ValidValue
id = cursorColId.CurrentDataValue.ValidValue
# now apply rules for scoring
if col1Val <= 3:
score -= 3
elif col1Val > 3 and col2Val > 50:
score += 10
else:
score += 5
text += "%d\t%f\r\n" % (id, score)
add_column(table, text, 'Score_Result')
For an approach with no scripting, but also no accumulation, you can use calculated columns.
To get the scores, you can use a calculated column with case statements. For Segment 1, you might have:
case
when [Col1] > 100 then 10
when [Col1] < 100 and [Col2] > 600 then 20
end
The, once you have the scores, you can create a calculated column, say [MaxSegment]. The expression for this will be Max([Segment1],[Segment2],[Segment3]...). Then display the value of [MaxSegment].
The max function in this case is acting as a row expression and is calculating the max value across the row of the columns given.