Forum Discussion
Percentiles from frequency table
You may group by Product without aggregation and apply former procedure to each group
let Source = Excel.CurrentWorkbook(){[Name="Table1"]}[Content], #"Grouped Rows" = Table.Group( Source, {"Product"}, {{"Percentile", each [ allValues = Table.AddColumn( _ , "Lists", each List.Numbers([Value],[Frequency],0) ), Percentile = List.Percentile ( List.Combine(allValues[Lists]), 0.5 ) ][Percentile] }} ) in #"Grouped Rows"or use function instead
let Source = Excel.CurrentWorkbook(){[Name="Table1"]}[Content], fnPercentile = (tbl as table) => let allValues = Table.AddColumn( tbl , "Lists", each List.Numbers([Value],[Frequency],0) ), Percentile = List.Percentile ( List.Combine(allValues[Lists]), 0.5 ) in Percentile, #"Grouped Rows" = Table.Group( Source, {"Product"}, {{ "Percentile", each fnPercentile(_) }} ) in #"Grouped Rows"Here the only we assume predefined column names in functions.
I'd filter Frequency = 0 before grouping.
In attached file is above and "Excel variant".
SergeiBaklan That's genius!
I'm trying to implement this in my real life data and have only one problem, the grouping by product. Imagine you would have sample data like this and want to calculate the median by product (see also attached workbook where I added the column):
You may group by Product without aggregation and apply former procedure to each group
let
Source = Excel.CurrentWorkbook(){[Name="Table1"]}[Content],
#"Grouped Rows" = Table.Group(
Source, {"Product"},
{{"Percentile",
each
[
allValues = Table.AddColumn(
_ ,
"Lists",
each List.Numbers([Value],[Frequency],0)
),
Percentile = List.Percentile (
List.Combine(allValues[Lists]), 0.5
)
][Percentile]
}}
)
in
#"Grouped Rows"or use function instead
let
Source = Excel.CurrentWorkbook(){[Name="Table1"]}[Content],
fnPercentile = (tbl as table) =>
let
allValues = Table.AddColumn(
tbl , "Lists",
each List.Numbers([Value],[Frequency],0)
),
Percentile = List.Percentile (
List.Combine(allValues[Lists]), 0.5
)
in
Percentile,
#"Grouped Rows" = Table.Group(
Source, {"Product"},
{{ "Percentile", each fnPercentile(_) }}
)
in
#"Grouped Rows"Here the only we assume predefined column names in functions.
I'd filter Frequency = 0 before grouping.
In attached file is above and "Excel variant".
SergeiBaklan You've been of great help, thank you! I managed to do it.
I like to use the Power Query UI as much as possible, and also go in gradual steps so I can understand afterwards what I did, so I ended up with this to make the lists:
let Source = Excel.CurrentWorkbook(){[Name="Table1"]}[Content], #"Changed Type" = Table.TransformColumnTypes(Source,{{"Product", type text}, {"Value", Int64.Type}, {"Frequency", Int64.Type}}), //List per Value #"Added Custom" = Table.AddColumn(#"Changed Type", "ListPerValue", each List.Numbers([Value], [Frequency], 0), type list), #"Removed Columns" = Table.RemoveColumns(#"Added Custom",{"Frequency"}), //List per product (combine lists per value for each product) #"Grouped Rows" = Table.Group(#"Removed Columns", {"Product"}, {{"ListPerProduct", each List.Combine([ListPerValue]), type list}}), //Show list to check #"Extracted Values" = Table.TransformColumns(#"Grouped Rows", {"ListPerProduct", each Text.Combine(List.Transform(_, Text.From), ","), type text}) in #"Extracted Values"First a simple "Add custom column", with the List.Number function.
Then the grouping by doing a generic sum grouping using the UI, then changing the sum function into List.Combine as you showed. The last step is just for checking the result.
Thanks again!
(Workbook attached for future reference).
bartvana you are welcome, glad to help.