Displaying 20 results from an estimated 10000 matches similar to: "Calculating difference between values in data frame based on separate column"
2011 Oct 20
1
Applying function with separate dataframe (calibration file) supplying some inputs
Hello,
I am not entirely sure the subject line captures what I am trying to do, but
hopefully this description of the problem will help folks to see my
challenge and hopefully offer constructive assistance.
I have an experimental setup where I measure the decrease in oxygen in small
vials as an organism, such as an oyster, consumes the oxygen. Each vial is
calibrated before the experiment and
2011 Aug 23
3
Linear Regression with 2 grouping variables
Hi all,
I have a data set that looks a bit like this.
feed1
RFU Site Vial Time lnRFU
1 44448 1 1 10 10.702075
2 47521 1 1 20 10.768927
3 42905 1 1 30 10.66674
4 46867 1 1 40 10.755069
5 42995 1 1 50 10.668839
6 43074 1 1 60 10.670675
7 41195 1 1 70 10.626072
8 47090 1 2 10 10.759816
9 48100 1
2004 Aug 03
1
(Lattice) How to improve the readability of a bwplot, i.e. separating groups somehow
Hi all,
first of all thanks for the answer to my previous question on lattice some
time ago.
In particular to Patrick Connolly for advices on netiquette (I hope this
time I'm doing right....)
and to Deepayan Sarkar fro the help on lattice.
Now, my nowaday problem.
Please consider the following
mydf<-cbind.data.frame(
RESPONSE = c(rnorm(9,rep(2:4,each=3),10),
2004 Oct 26
1
indexing within the function "aggregate"
Hi all,
I'm trying to work out the following problem, but I can't imagine how.
I have the following (much reduced & oversimplified) dataset
My.df <-
cbind.data.frame(PPM=c(15.78, 15.81, 15.87, 15.83, 15.81, 15.84,
15.91, 15.90, 15.83, 15.81, 15.93, 15.83,
15.70, 15.92, 15.76, 15.81, 15.91, 15.75,
15.84, 15.86, 15.82, 15.79,
2003 May 13
1
assessing the fit of a LME model
Dear All,
I would like to ask a couple of questions on a LME model.
I tested 4 selection lines at 4 food concentrations against a standard
competitor stock. I had 3 replicate cages per selection line. In each cage
I have 10 vials. I counted the number of wild type flies and competitor
stock emerging in each vial. My main question is: is there any difference
between selection lines?
I did fit
2010 Apr 21
1
Degrees of Freedom Not Allocated to Residuals in Reduced Model
##I am trying to test for fixed factor main effects in an unbalanced mixed effects model but when I fit the reduced model for "mic" factor effects, the extra degrees of freedom are being allocated to a nested term rather than the residuals. The model has inc, mic and spp are independent variables and vial nested within spp. inc and spp are already coded as factors since they were
2011 Feb 26
1
Transform a dataset from long to wide using reshape2
I seem to be running into the same problem reported in
https://stat.ethz.ch/pipermail/r-help/2010-November/258265.html
I cannot seem to transform a dataset from long to wide using reshape2.
Clearly I am missing something very simple but a look at the manual and the reshape paper in JSS does not suggest anything.
Any advice would be welcome
===========================load
2011 Sep 09
4
reshape data from long to wide format
This is my reproducible example:
example<-structure(list(SENSOR = structure(1:6, .Label = c("A", "B", "C",
"D", "E", "F"), class = "factor"), VALUE = c(270, 292.5, 0, 45,
247.5, 315), DATE = structure(1:6, .Label = c(" 01/01/2010 1",
" 01/01/2010 2", " 01/01/2010 3", " 01/01/2010
2012 Nov 17
3
Reshaping a dataframe
Seems like this should be easy but I'm struggling a bit. How do I rearrange a
data frame to go from the first one to the second shown below ?
State Date lbs
TX 200701 400
TX 200702 650
TX 200703 950
TX 200704 1000
FL 200701 200
FL 200702 300
FL 200703 500
FL 200704 333
NJ 200701 409
NJ 200702 308
NJ 200703 300
NJ 200704 800
Date TX FL NJ
200701 400 200 409
200702 650
2011 Aug 02
2
Data frame to matrix - revisited
Hi,
I've tried to look through all the previous related Threads/posts but can't find a solution to what's probably a simple question.
?
I have a data frame comprised of three columns e.g.:
?
ID1?ID2?Value
a?b?1
b?d?1
c?a?2
c?e?1
d?a?1
e?d?2
?
I'd like to convert the data to a matrix i.e.:
?
?a b c d e
a n/a 1 2 1 n/a
b 1 n/a n/a 1 n/a?
c 2 n/a n/a n/a 1
d 1 1 n/a n/a 2
e n/a n/a 1
2011 Aug 08
1
Help on reshape2 data frame rearrangement
Dear help list: I am trying to reshape a data frame from long to wide format and with a reduced variable list using reshape2. The original data frame format is: Site Obs_no LengthSite 1 Obs 1 10Site 1 Obs 2 13Site 1 Obs 3 14.........Site 2 Obs 1 5Site 2 Obs 2 7Site 2 Obs 3 9 Site and Obs_no are factors and Length is a numeric variable. There are 15
2011 Feb 23
1
Fwd: Re: sum data from data.frame in a matrix
Hi Dennis,
Thanks for your quick response and sorry for not being clear. That
helped, but I need an actual matrix of e.g., 12 x 12 and those functions
give me a matrix with only the "filled" locations. I need a 12 by 12
matrix with sums (0 if there's not data and the actual sum where there
is) as follows:
1 2 3 4 5 6 7 8 9 10 11 12
1 0 0 0 . . . . . . 0 0 0
2 0 0 0 .
3 0
2011 Feb 03
3
R Data Manipulation - Transposing Data by a Given Column, Like User_ID
Hello,
I'd like to transpose data to create an analysis-friendly dataframe. See
below for an example, I was unable to use t(x) and I couldn't find a
function with options like PROC TRANSPOSE in SAS.
The ideal solution handles variable quantities of SITE - but beggars can't
be choosers. :-)
Thank you in advance,
Mike
## INPUT DATA
USER_ID<-c(1,1,1,2,2,2,3,3,4)
SITE
2011 May 20
1
Factors to Columns
> str(data)
'data.frame': 250 obs. of 3 variables:
$ student: chr "A" "B" "C" "D" ...
$ data : num 20.2 20.4 22.5 22.1 23.3 ...
$ param : Factor w/ 4 levels "AGE","SCHOOL",..: 1 1 1 1 1 1 1 1 1 1
Hi , i would like to split the dataframe so that each level of param is
a column
At the end it should look like
2011 Oct 27
2
Syntax Check: rshape2 melt()
This is my first excursion into using reshape2 and I want to ensure that
the melt() function call is syntactically correct.
The unmodifed data frame is organized this way:
head(tds.anal)
site sampdate param quant
1 UDS-O 2006-12-06 TDS 10800
4 STC-FS 1996-06-14 Cond 280
7 UDS-O 2007-10-04 Mg 1620
9 UDS-O 2007-10-04 SO4 7580
19 JCM-10B 2007-06-21 Ca 79
20
2011 Oct 20
2
Aggregating data help
Hello,
I have a dataset with student performance on a math test. There are
multiple cases for each student (identified by id) and the concept as a
variable.
> rtest
id test subject grade concept correct tested per_corr
year
1 1 83 Mathema 8 8.2.D 1 1 100
2011
2 1 83 Mathema 8 8.3.A 1 2
2011 Aug 08
1
Reshape2 sytax
Hi Hadley et all,
I am struggling with reshape2 and melt works and melt_check
(filtered151) seems fine
My cast command was acast (filtered151, Time ~ Species ~ Number)
> melt_check (filtered151)
Using time, Species as id variables
$id
[1] "time" "Species"
$measure
[1] "Number"
When I execute cast the data matrix is in the correct order but the data
2010 Nov 01
2
transforming a dataset for association analysis RESHAPE2
I get the following message when using the reshape2 package line
> tDat.m<- melt(Dataset)
Using Item, Subject as id variables
> tDatCast<- acast(tDat.m,Subject~Item)
Aggregation function missing: defaulting to length
Note Problem Statement-
convert dataframe
Subject Item Score
1 Subject 1 Item 1 1
2 Subject 1 Item 2 0
3 Subject 1 Item 3 1
4 Subject 2 Item 1 1
5
2011 Apr 21
1
Stymied by plyr
Hello, This is my first time trying to use plyr, and I'm getting
nowhere. I have teacher ratings data (1:4), on 10 components, by
external observers and internal observers, in schools in areas. I want
to calculate the percentage of each rating given on each component, by
each type of observer, within each school, within each area. The data
look like this:
unit area ext.obs rating comp
11
2012 Dec 13
2
More efficient use of reshape?
Hi all,
I have played a bit with the "reshape" package and function along with
"melt" and "cast", but I feel I still don't have a good handle on how to
use them efficiently. Below I have included a application of "reshape" that
is rather clunky and I'm hoping someone can offer advice on how to use
reshape (or melt/cast) more efficiently.
#For this