similar to: difference of two rows

Displaying 20 results from an estimated 40000 matches similar to: "difference of two rows"

2009 Feb 09
2
length of object in repeated measures
Hi there. I collectad data of several animals (Id) that were caught and measured at several occasions. The dataframe looks like this: Grouped Data: mass ~ age | Id Id age mass 1 1 5.4 1 3 6.2 1 15 10.0 2 3 8.1 2 10 12.8 3 2 5.9 3 10 7.1 3 15 15.4 3 17
2009 Oct 21
1
re ferring to data of previous rows
Dear Rlers, in the following dataset I would like to insert a new column that refers to the data of the previous row. My question is whether the probability of a female (Id) changes if she had given birth to a pup in the previous year. So my dataframe consists of the column Id, year (2003-2007 for each Id) and offspring (=of; 1-0): Id year of 1 2003 1 1 2004 0 1
2009 Feb 20
3
mean over previous cells
Dear RUsers, I guess this is an easy question for someone a little familiar with programming...(which I am not)... I've got 2 colummns, one shows just dates(SST_date, Class 'Date' num), the other one shows the SeaSurfaceTemperature (SST, num) at that certain date. SST_date SST 2008-01-01 22.2 2008-01-02 21.8 2008-01-03 22.8 2008-01-04 22.9 2008-01-05 23.1 2008-01-06 23.2 ...
2009 Jul 09
2
How to combine two rows (in a dataframe) into a third row?
Dear R-helpers, I have two rows in my dataframe: ID VALUE 1A 10 1B 15 and I would like to combine these two rows into a single (new) row in my dataframe: ID VALUE 1 25 ...simply by specifying a new value for ID and summing the two VALUES. I have been trying to do this with with rbind, but it's not working. I'd appreciate any pointers. Thanks, Mark Na [[alternative
2010 Aug 24
2
How to remove rows based on frequency of factor and then difference date scores
Hello- A basic question which has nonetheless floored me entirely. I have a dataset which looks like this: Type ID Date Value A 1 16/09/2020 8 A 1 23/09/2010 9 B 3 18/8/2010 7 B 1 13/5/2010 6 There are two Types, which correspond to different individuals in different conditions, and loads of ID labels (1:50)
2010 Jun 08
2
how to ignore rows missing arguments of a function when creating a function?
Hi, I am relatively new to R; when creating functions, I run into problems with missing values. I would like my functions to ignore rows with missing values for arguments of my function) in the analysis (as for example is the case in STATA). Note that I don't want my function to drop rows if there are missing arguments elsewhere in a row, ie for variables that are not arguments of my
2004 Aug 03
2
attach data from tapply to dataframe
I am working with a longitudinal data set in the long format. This data set has three observations per grade level per year. Here are the first 10 rows of the data frame: >tenn.dat[1:10,] year schid type grade gain se new cohort 6 2001 100005 5 4 33.1 3.5 4 3 7 2002 100005 5 4 33.9 3.9 4 2 8 2003 100005 5 4 32.3 4.2 4 1 10 2001 100005
2012 Aug 23
1
Extracting data from dataframe with tied rows
Hi R help, I'm a fairly experienced R user but this manipulation has me stumped, please help: DATA id<-rep(LETTERS[1:5],20) distance<-rnorm(1:100, mean = 100) bearing<-sample(1:360,100,replace=T) month<-sample(1:12,100,replace=T) I have a dataset with records of individuals (id) , each with a distance (distance) & direction (bearing) recorded for each month (month). I want
2007 Mar 20
6
Select the last two rows by id group
Hi R-users, Following this post http://tolstoy.newcastle.edu.au/R/help/06/06/28965.html , how do I get last two rows (or six or ten) by id group out of the data frame? Here the example gives just the last row. Sincere thanks, Lauri [[alternative HTML version deleted]]
2006 Dec 07
2
Splitting a dataframe at the results of tapply
I have got a dataframe containing measurement of aircraft noise like this: > Id <- c(1,4,5,2,3,6,4,1,2,5,6,3) > Noise <- c(88,94,97,98,92,56,103,102,87,95,92,97) > Height <- c(190, 150, 120, 115, 188, 104, 101, 189, 146, 111, 124, 126) > > df <- data.frame(Id, Noise, Height) Now I would like to split this in two new dataframes. The first one containing the rows
2011 Jan 25
5
Counting number of rows with two criteria in dataframe
Hi R-users, I'm trying to find an elegant way to count the number of rows in a dataframe with a unique combination of 2 values in the dataframe. My data is specifically one column with a year, one with a month, and one with a day. I'm trying to count the number of days in each year/month combination. But for simplicity's sake, the following dataset will do:
2009 Feb 23
1
"autonumber" for grouping variable
Dear R users, my dataframe looks like this head(dat) Id sex byear age 1 300 m 2003 50 2 300 m 2003 36 3 402 f 2003 29 4 402 f 2003 21 5 402 f 2003 64 6 150 m 2005 43 ... ...(where Id is just the Identification number of Individual, sex (male or female), byear (=birthyear)) now, I 'd like to add a column, where each Individual gets an automated number starting
2006 Feb 24
3
Summarize by two-column factor, retaining original factors
I am having trouble doing the following. I have a data.frame like this, where x and y are a variable that I want to do calculations on: Name Year x y ab 2001 15 3 ab 2001 10 2 ab 2002 12 8 ab 2003 7 10 dv 2002 10 15 dv 2002 3 2 dv 2003 1 15 Before I do all the other things I need to do with this data, I need to summarize or collapse the data by name and year. I've
2009 Feb 27
3
Making tapply code more efficient
Previously, I posed the question pasted down below to the list and received some very helpful responses. While the code suggestions provided in response indeed work, they seem to only work with *very* small data sets and so I wanted to follow up and see if anyone had ideas for better efficiency. I was quite embarrased on this as our SAS programmers cranked out programs that did this in the blink
2008 Nov 20
2
Calculating SD according to groups of rows
*Hi all, I know this is probably basic, but I have proven to be a slow learner in any programming language. Anyhow, how can I calculate the SD for each person in my table? I have two patients in this R data.frame, 7200 and 23955. I extracted this from a relational database, but am I better off attempting to compute SD in SQL, or is this easily accomplished in R? * SUBJECT_ID HR 1
2010 Dec 24
4
Removing rows with earlier dates
Hi all, I'm new to the list but have benfited from it quite extensively. Straight to my rather strange question: I have a data frame that contains mapping rules in this way: ACCOUNT, RULE COLUMNS, Effective Date The dataframe comes from a database that stores all dates. What I would like to do is to create a data frame with only the most recent rule for each account. In traditional
2011 Nov 06
1
Combining some duplicated rows & summing one of their column
Dear list, I have this dataframe: > names(events) [1] "EID" "X" "Y" "trip" "tow" "catch" "effort" "depth" [9] "season" Where some of my unique ID "EID" appears more than once in 162 cases. > length(events$EID)-length(unique(events$EID)) [1] 162 I would like to combined
2010 Jun 29
2
How to delete rows based on replicate values in one column with some extra calcuation
Hi, folks, Please let me address the problem by the following codes: first=c('u','b','e','k','j','c','u','f','c','e') second=c('usa','Brazil','England','Korea','Japan','China','usa','France','China','England') third=1:10
2006 May 30
2
average by group...
I have a dataframe with 700,000 rows and 2 vectors (columns): ?group? and ?score?. I wish to calculate a third vector of length 700000: the average score by group. Even though the avarge value will repeat, I wish to return the average for that particular group for each row. (I know I can do this by calculating each group?s average and then using the merge command, but as my calculations get
2001 Mar 22
2
Two-argument functions in tapply()
Hello to all. My question is very simple... Let's say we have a data frame with three variables (columns): X, W and F. X is a numeric variable (e.g. like income) F is a factor (e.g. with 2 levels) and W is a case weight (data are from household sample but an individual was interviewed, weights are functions of number of persons in the house hold). I wanted to compute a means of X weighted