I finally figured this out with the help of Dave and Dennis.
The steps I had to do were
1. Convert dates to POSIXlt
2. Create a column in each frame that was paste(date, quarter)
3. Then %in% worked instantly.
gw = c(length(arr))
gw[1:length(arr[,1])]=FALSE
arr[gw]=gw # put a column of 0s
I don't think it is that simple because it is not a one-to-one match. In
the arr data frame, there are many arrivals in a quarter hour with good
weather on a given day. So I need to match the date and the quarter hour.
And all of the rows in the weather data frame are times with good
On Jan 17, 2010, at 12:37 PM, James Rome wrote:
I don't think it is that simple because it is not a one-to-one
match. In
the arr data frame, there are many arrivals in a quarter hour with
good
weather on a given day. So I need to match the date and the quarter
hour.
And all of the rows
On 1/17/10 1:06 PM, David Winsemius wrote:
On Jan 17, 2010, at 12:37 PM, James Rome wrote:
I don't think it is that simple because it is not a one-to-one match. In
the arr data frame, there are many arrivals in a quarter hour with good
weather on a given day. So I need to match the date
SInce you provided no data, it is hard to determine how to compare. If you
also want the date, then the following will work:
arr$GoodWeather - arr$quarter %in% gw$quarter arr$date %in% gw$date
If your quarter is just the minutes of arrival, you may have to convert
that to the appropriate
Thank you Dennis.
arr$gw - as.numeric(weather$Date == arr$Date arr$quarter %in%
weather$quarter)
seems to be what I want to do, but in fact, with the full data set, it
misidentifies the rows, so I think the error message must mean something.
arrr$Date -
My guess (since we still have no data on which to test these ideas)
is that you need either to merge() or to use a matrix created from the
dates and qtr-hours entries in gw, since matching on dates and hours
separately will not uniquely classify the good qtr-hours within their
proper
Here are some sample data sets.
I also tried making a combined field in each set such as
adq=paste(as.character(arr$Date), as.character(arr$quarter))
and similarly for the weather set, so I have unique single things to
compare, but that did not seem to help much.
Thanks,
Jim
On 1/17/10 5:50 PM,
But, but, but there is no weather goodness variable in
weather?!?!?!
str(weather)
'data.frame': 155 obs. of 4 variables:
$ Date :Class 'Date' num [1:155] 14245 14245 14245 14245 14245 ...
$ minute : int 5 15 30 45 0 15 30 45 0 15 ...
$ hour : int 15 15 15 15 17 17 17 17 18
Any entry in the weather data is a good day. That is the point. And
please ignore my mistake about the quarters getting too large in
weather. I am being swamped with versions, and it does not matter for
this purpose.. so, the bad weather days are not in the weather data set.
I am trying to get
I have two data frames. One (arr) has all arrivals to an airport for a
year, and the other (gw) has the dates and quarter hour of the day when
the weather is good. arr has a Date and quarter hour column.
names(arr)
[1] Date weekday hour monthminute
[6] quarter
Hi,
it looks like when you read in your data.frames, you didn't tell R to
expect dates, so it treats the Date columns as factors. Judicious use of
something along these lines before doing your comparisons may help:
arr$Date - as.Date(as.character(arr$Date),format=something)
Then again, it
I don't want to merge the data frames because there are many entries
in the arrival frame for each one in the weather frame. And it is the
missing dates and quarters in the weather frame that constitute the date
I want, namely those arrivals that occurred in bad (or good) weather.
But I will
If you have a vector of the quarter hours of good weather (gw), then to
create the column in the arr dataframe you would do
arr$GoodWeather - arr$quarter %in% gw
This says that if the quarter hour of the arrival is in the 'gw' vector, set
the value TRUE; otherwise FALSE.
On Sat, Jan 16, 2010 at
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