Here is how you should be creating your dataframe so that each element
has the proper mode:
> days=Sys.Date()-1:70
> price=abs(rnorm(70))
> regular=rep(c(0,0,0,0,1,0,1,0,0,1),c(7,7,7,7,7,7,7,7,7,7))
> y=data.frame(cbind(days,price,regular))
> str(y)
'data.frame': 70 obs. of 3 variables:
$ days : num 14991 14990 14989 14988 14987 ... # notice is it numeric
$ price : num 0.626 0.184 0.836 1.595 0.33 ...
$ regular: num 0 0 0 0 0 0 0 0 0 0 ...
> y <- data.frame(days, price, regular)
> str(y)
'data.frame': 70 obs. of 3 variables:
$ days :Class 'Date' num [1:70] 14991 14990 14989 14988 14987 ...#
here it is 'Date'
$ price : num 0.626 0.184 0.836 1.595 0.33 ...
$ regular: num 0 0 0 0 0 0 0 0 0 0 ...
> y
days price regular
1 2011-01-17 0.62645381 0
2 2011-01-16 0.18364332 0
3 2011-01-15 0.83562861 0
4 2011-01-14 1.59528080 0
5 2011-01-13 0.32950777 0
6 2011-01-12 0.82046838 0
7 2011-01-11 0.48742905 0
8 2011-01-10 0.73832471 0
On Mon, Jan 17, 2011 at 9:59 AM, Daniel Wu <daniel_w...@163.com> wrote:
> days=Sys.Date()-1:70
> price=abs(rnorm(70))
> regular=rep(c(0,0,0,0,1,0,1,0,0,1),c(7,7,7,7,7,7,7,7,7,7))
> y=data.frame(cbind(days,price,regular))
>
>
> y is like
> days price regular
> 1 14990 0.16149463 0
> 2 14989 1.69519358 0
> 3 14988 1.57821998 0
> 4 14987 0.47614311 0
> 5 14986 0.87016180 0
> 6 14985 2.55679229 0
> 7 14984 0.89753533 0
>
>
> the output I want:
> have another column appended to y, whose value is the max price in the recent
> 2 **regular** weeks.
> So if the current row is today, then get the max price of the past 14 days
> (including today) if the last 2 week are regular weeks, if one of the last 2
> weeks is not regular week, then I need to go back further to find the max
> price, as I need the max price for the last 2 **regular** weeks. How can I do
> that? Or I have to use loop/if to do it?
>
>
>
>
> BTW, why the days is like 14990,14989, after cbind(days,price,regular)?
> before the cbind, days is like the format "2010-12-23".
> [[alternative HTML version deleted]]
>
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> and provide commented, minimal, self-contained, reproducible code.
>
--
Jim Holtman
Data Munger Guru
What is the problem that you are trying to solve?
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