Displaying 20 results from an estimated 3000 matches similar to: "difficulty in Formatting time series data"
2012 Jul 14
2
writing data into files whose names are in a vector
GuRus
How do I use the write function (or write.table or write.csv) to achieve
the following please?
age=c(32,37,39)
names=c("john","peter","jake")
I would like create in a directory 3 files each named as john.csv,peter.csv
and jake.csv and each file have data from the age vector. That is jon.csv
will contain 32, peter.csv will contain 37 and jake.csv will contain
2012 Jul 08
3
Help in Optimization of a function
guRus!
I have a function f = exp(x^2-y+(1/z))
Also, x can take values from 1 to 37, y from 2 to 20 and Z from -13 to 51.
How can I find the maximum of f using any of the optimization functions
please?
Is there a way to store the possible values of x, y and Z in a single
variable like in a List or in a multi-dimensional array?
Thanks for your help
Raghu
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2012 Jul 24
3
Collapsing a vector/data-frame based on the previous values
Hello
I have a data frame like this:
dput(states)
structure(list(Date = c("24/07/2012", "25/07/2012", "26/07/2012",
"27/07/2012", "28/07/2012", "24/07/2012", "25/07/2012", "26/07/2012",
"27/07/2012", "28/07/2012"), State = c(1L, 1L, 1L, 1L, 1L, -1L,
-1L, -1L, 1L, -1L)), .Names = c("Date",
2012 Jun 19
1
Profit calculation
Dear guRus
Say I have a price vector, P which is P = c(20,50,40,50) for four
consecutive days.
My initial equity is say $100 and I re-invest the profits made in each
transaction so my equity curve increases.
If I go Long on day 1, short and short on day 2, long and long on day 3 and
finally short on day 4, how do I calculate the total profits using R?
Basically I stay invested at all times.
I
2010 Aug 06
2
How to read a file inside a function?
Hi
I wish to read a file from my local directory from inside a function. I am
passing the filename as the argument but this does not work.
Say for example
function(dat)
{
dat1=read.csv("D:\\dat.csv",header=TRUE)
}
If I call funtion(dat) I get the following error. 'Intuitively' i understand
this is a mistake but how do I overcome this and how can I read a file name
passed as an
2010 Aug 06
3
How to apply apply?!
guRus
I have say a dataframe, d and I wish to do the following:
1) For each row, I want to take one particular value of the row and multiply
it by 2. How do I do it. Say the data frame is as below:
OPEN HIGH LOW CLOSE 1931.2 1931.2 1931.2 1931.2 0 0 0 999.05 0 0 0 1052.5
0 0 0 987.8 0 0 0 925.6 0 0 0 866 0 0 0 1400.2 0 0 0 754.5 0 0 0 702.6 0 0 0
653.25 0 0 0 348 0 0 0 801 866.55 866.55
2024 May 09
2
Strange variable names in factor regression
On converting character variables to ordered factors, regression result
has strange names. Is it possible to obtain same variable names with
and without intercept?
Thanks,
Naresh
mydf <- data.frame(date = seq.Date(as.Date("2024-01-01"),
as.Date("2024-03-31"), by = 1))
mydf[, "wday"] <- weekdays(mydf$date, abbreviate = TRUE)
mydf.work <- subset(mydf, !(wday
2007 Oct 15
1
String concatenation, File Path Handling to pass to download.file( ) [backslash in DOS paths]
Gabor,
Thanks much. Your solution is elegant. My overall scheme is to take
present date, and check whether it is a weekend, if not, then create a
string based on the date, to concatenate into a url link for
download.file( ). The files I need to download have a part which is in
the format: mmddyy. I am working to make myself a system to connect to
exchanges, and download end of day files from
2003 Aug 13
1
Problems with addition in big POSIX dates
Have you noticed any problems with big dates (>=1/1/2040) in R?
Here is the bit of code that I'm having trouble with:
> test.date <- strptime("1/1/2040",format="%m/%d/%Y")
>
> unlist(test.date)
sec min hour mday mon year wday yday isdst
0 0 0 1 0 140 0 0 0
>
> date.plus.one <- as.POSIXct(test.date) +
2010 Jul 28
3
how to code it??
Hi
I have say a large vector of 3500 digits. Initially the digits are 0s and
1s. I need to check for a rule to change some of the 0s to -1s in this
vector. But once I change a 0 to -1 then I need to start applying the rule
to change the next 0 only after I see the next 1 in the vector.
Say for example x = (0,0,0,0,0,0,0,1,0,0,1,1,0,0,1,0,0,0,1)
I need to traverse from the 9th element to the last
2006 Apr 10
4
Best way to propogate model rules to controller?
Hey everybody,
I''ve got a model that represents kind of a turn-based games. Certain
actions can only be made unders certain conditions. For simplicity,
we''ll say that the only condition for a particular action is that the
weekday be Tuesday.
def add_vote
raise ''You cannot vote today'' unless Date.today.wday == 2
...
end
In my controller I want to show a
2006 Jul 20
2
workweek_select
I''m having difficulty figuring out the ruby neccessary to do this so I
thought I would try the list. I''m hoping to get a date_select to only
display certain days (specifically only fridays) but rails doesn''t
seem to have the flexibility so I''ve been going at it in ruby to no
avail.
I''ve looked on google but couldn''t find it (because it
2010 Jul 28
2
finding the next highest number in an array
Hi
I have a sorted array ( in ascending order) and I want to find the subscript
of a number in the array which is the the next highest number to a given
number. For example,if I have 67 as a given number and if I have a vector
x=c(23,36,45,62,79,103,109), then how do I get the subscript 5 from x (to
get 79 which is the next highest to 67) without using a for loop?
Thx
--
'Raghu'
2010 Jul 06
4
Adding two files into one and vlookup
I have two files with dates and prices in each. The number of rows in each of
them will differ. How do I create a new file which contains data from both
these files? Cbind and merge are not helpful. For cbind because the rows are
not the same replication occurs. Also if I have similar data how do I write
a vlookup kind of function? I am giving an example below:
Say Price1 file contains the
2010 Jul 12
2
a small puzzle?
I know the following may sound too basic but I thought the mailing list is
for the benefit of all levels of people. I ran a simple if statement on two
numeric vectors (news1o and s2o) which are of equal length. I have done an
str on both of them for your kind perusal below. I am trying to compare the
numbers in both and initiate a new vector s as 1 or 0 depending on if the
elements in the arrays
2010 Jul 12
6
in continuation with the earlier R puzzle
When I just run a for loop it works. But if I am going to run a for loop
every time for large vectors I might as well use C or any other language.
The reason R is powerful is becasue it can handle large vectors without each
element being manipulated? Please let me know where I am wrong.
for(i in 1:length(news1o)){
+ if(news1o[i]>s2o[i])
+ s[i]<-1
+ else
+ s[i]<--1
+ }
--
2006 May 16
10
Date verus Time class
I''m using the date_select and datetime_select helpers in my view, and
they return Date classes from the params hash.
But how do I work with Date classes, they don''t print human readable
dates or times, Time classes work well I can use strftime("%H:%M") to
print to the screen.
Is it possible to convert a Date to a Time, Ive been tinkering in irb
but have got
2008 Apr 04
4
How can we creat conditional data frame
Hi,
R experts. I am a new user of R and trying to learn this program.
I have a problem. Here is the code.
d<-as.Date(c("2000/01/03","2000/01/05","2000/01/19","2000/01/28"))
r<-rnorm(4)
da<-data.frame(d,r)
a<-as.Date("01/01/2000","%d/%m/%Y")
b<-as.Date("30/01/2000","%d/%m/%Y")
ab<-seq(a,b,by=1)
2012 Jul 10
1
Help with vectors and rollapply
Hello
I have a vector a =(-2,0,0,0,1,0,0,3,0,0,-4)
I want to replace all zeros into previous non-zero state. So for instance the above vector should be converted into:
a= (-2,-2,-2,-2,1,1,1,3,3,3,-4)
I tried many things and finally concluded that probably(?) rollapply may be the best way?
I tried
f= function(x){
ifelse(x==0,Lag(x),x)
}
And then, rollappy(a,1,f) and that
2009 Nov 03
1
How to display full name for the coefficients/factors in summary()?
Hi,
I am wondering if there is a way to display the full anme of the
regression coeffients/factors in the summary?
Suppose I have a bogus data set using weekday as factor which has 7 levels
such as:
mydata <- sample(364)
wk <- rep(1:7, 52)
weekday <-