Re: How can I totalize by month, by year?
- To: mathgroup at smc.vnet.net
- Subject: [mg111899] Re: How can I totalize by month, by year?
- From: David Carraher <david_carraher at terc.edu>
- Date: Wed, 18 Aug 2010 07:04:52 -0400 (EDT)
Hi Leandro,
Here's one approach. Other folks will find other ways, I'm sure....
Below are your data (minus the outer pair of curly braces).
In[1]:=
data = {
{{2010, 8, 3, 0, 0, 0.}, 65.},
{{2010, 8, 3, 0, 0, 0.}, -72.},
{{2010, 8, 3, 0, 0, 0.}, 45.},
{{2010, 8, 2, 0, 0, 0.}, 67.},
{{2010, 8, 2, 0, 0, 0.}, 83.},
{{2010, 8, 2, 0, 0, 0.}, -42.},
{{2010, 7, 30, 0, 0, 0.}, -32.},
{{2010, 7, 30, 0, 0, 0.}, 48.},
{{2010, 7, 30, 0, 0, 0.}, 12.},
{{2010, 7, 30, 0, 0, 0.}, 34.},
{{2010, 7, 29, 0, 0, 0.}, -52.},
{{2010, 7, 29, 0, 0, 0.}, 78.},
{{2010, 7, 29, 0, 0, 0.}, -26.},
{{2010, 7, 28, 0, 0, 0.}, 45.},
{{2010, 7, 28, 0, 0, 0.}, -23.},
{{2010, 7, 28, 0, 0, 0.}, -32.},
{{2010, 7, 28, 0, 0, 0.}, 74.},
{{2010, 7, 27, 0, 0, 0.}, 53.},
{{2010, 7, 27, 0, 0, 0.}, 58.},
{{2010, 7, 27, 0, 0, 0.}, 25.}};
(*
Here's one approach
GatherBy gathers the transactions from like dates.
Transpose puts the amounts for each data into lists.
Plus sums the list of amounts
*)
In[2]:=
Transpose /@ GatherBy[data, First] /. {dates_, sum_List} :> {
First[dates], Plus @@ sum}
Out[2]=
{
{{2010, 8, 3, 0, 0, 0.}, 38.},
{{2010, 8, 2, 0, 0, 0.}, 108.},
{{2010, 7, 30, 0, 0, 0.}, 62.},
{{2010, 7, 29, 0, 0, 0.}, 0.},
{{2010, 7, 28, 0, 0, 0.}, 64.},
{{2010, 7, 27, 0, 0, 0.}, 136.}}
From: "Leandro Tenfen" <leandrotenfen at hotmail.com>
To: mathgroup at smc.vnet.net
Date: 08/17/2010 07:52 AM
Subject: [mg111899] [mg111895] How can I totalize by month, by year?
Hi,
I'm new with Mathematica, I need some help to start it.
I've got a date series like a cashflow, how can I totalize at each date
change? And how can I totalize by month, by year, etc?
For example:
In[]=
{{{{2010, 8, 3, 0, 0, 0.},
65.}, {{2010, 8, 3, 0, 0, 0.}, -72.}, {{2010, 8, 3, 0, 0, 0.},
45.}, {{2010, 8, 2, 0, 0, 0.}, 67.}, {{2010, 8, 2, 0, 0, 0.},
83.}, {{2010, 8, 2, 0, 0, 0.}, -42.}, {{2010, 7, 30, 0, 0,
0.}, -32.}, {{2010, 7, 30, 0, 0, 0.},
48.}, {{2010, 7, 30, 0, 0, 0.}, 12.}, {{2010, 7, 30, 0, 0, 0.},
34.}, {{2010, 7, 29, 0, 0, 0.}, -52.}, {{2010, 7, 29, 0, 0, 0.},
78.}, {{2010, 7, 29, 0, 0, 0.}, -26.}, {{2010, 7, 28, 0, 0, 0.},
45.}, {{2010, 7, 28, 0, 0, 0.}, -23.}, {{2010, 7, 28, 0, 0,
0.}, -32.}, {{2010, 7, 28, 0, 0, 0.},
74.}, {{2010, 7, 27, 0, 0, 0.}, 53.}, {{2010, 7, 27, 0, 0, 0.},
58.}, {{2010, 7, 27, 0, 0, 0.}, 25.}}}
Out[]=
{{{{2010, 8, 3, 0, 0, 0.}, 38.}, {{2010, 8, 2, 0, 0, 0.},
108.}, {{2010, 7, 30, 0, 0, 0.},
28.}, {{2010, 7, 29, 0, 0, 0.}, -10.}, {{2010, 7, 28, 0, 0, 0.},
64.}, {{2010, 7, 2, 0, 0, 0.}, 136.}}}
Thanks
Leandro Tenfen