> On Jun 21, 2017, at 2:50 PM, Ek Esawi <esaw...@gmail.com> wrote:
>
> I have a data.table which is shown below. I want to count combinations of
> columns on i and count on j with by. A few examples are given below the
> table.
>
>
>
> I want to:
>
> all months to show on the output including those that they have zero value
>
> I want the three statements combined in on if possible so the output will
> be one data table; that is the outputs are next to each other as manually
> illustrated on the last part (desired output).
>
>
>
>
>
> Thanks--EK
>
>
>
>
>
>> Test
>
> Color Grade Value Month Day
>
> 1: yellow A 20 May 1
>
> 2: green B 25 June 2
>
> 3: green A 10 April 3
>
> 4: black A 17 August 3
>
> 5: red C 5 May 5
>
> 6: orange D 0 June 13
>
> 7: orange E 12 April 5
>
> 8: orange F 11 August 8
>
> 9: orange F 99 April 23
>
> 10: orange F 70 May 7
>
> 11: black A 77 June 11
>
> 12: green B 87 August 33
>
> 13: black A 79 April 9
>
> 14: green A 68 May 14
>
> 15: black C 90 June 31
>
> 16: green D 79 August 11
>
> 17: black E 101 April 17
>
> 18: red F 90 June 21
>
> 19: red F 112 August 13
>
> 20: red F 101 April 20
You should have offered the output of:
dput(Test)
>
>> Test[Color=="green"&Grade=="A", .N, by=Month]
>
> Month N
>
> 1: April 1
>
> 2: May 1
>
>> Test[Color=="orange"&Grade=="F", .N, by=Month]
>
> Month N
>
> 1: August 1
>
> 2: April 1
>
> 3: May 1
>
>
>
>> Test[Color=="orange"&Grade=="F", .N, by=Month]
>
> Month N
>
> 1: August 1
>
> 2: April 1
>
> 3: May 1
>
>> Test[Color=="red"&Grade=="F", .N, by=Month]
>
> Month N
>
> 1: June 1
>
> 2: August 1
>
> 3: April 1
>
>
>
> Desired output
>
> N1 N2 N3
>
> April 1 1 1
>
> May 1 1 1
>
> June 0 0 0
>
> August 0 1 1
I count 4 data.tables and a total of 11 items so why only 3 columns and 9 items?
Were you tabulating colors by month?
> Test[ (Color=="green"&Grade=="A") |
(Color=="red"&Grade=="F") |
(Color=="orange"&Grade=="F")|
(Color=="orange"&Grade=="F")|
(Color=="red"&Grade=="F") , table(Month, Color)]
Color
Month green orange red
April 1 1 1
August 0 1 1
June 0 0 1
May 1 1 0
>
>
> [[alternative HTML version deleted]]
Rhelp is plain-text. Do read the Posting Guide:
Another possibility:
Test[(Color=="green"&Grade=="A") | These are the conditions separated by
logical OR's in the first argument to `[data.table`
(Color=="red"&Grade=="F") |
(Color=="orange"&Grade=="F")|
(Color=="orange"&Grade=="F")|
(Color=="red"&Grade=="F") , table(Month, Grade)]
Grade
Month A F
April 1 2
August 0 2
June 0 1
May 1 1
> ______________________________________________
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> and provide commented, minimal, self-contained, reproducible code.
David Winsemius
Alameda, CA, USA
______________________________________________
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