Displaying 20 results from an estimated 400 matches similar to: "NADA Package: Referencing Data Frame Columns"
2012 Jul 03
2
NADA Data Frame Format: Wide or Long?
I have water chemistry data with censored values (i.e., those less than
reporting levels) in a data frame with a narrow (i.e., database table)
format. The structure is:
$ site : Factor w/ 64 levels "D-1","D-2","D-3",..: 1 1 1 1 1 1 1 1 ...
$ sampdate: Date, format: "2007-12-12" "2007-12-12" ...
$ preeq0 : logi TRUE TRUE TRUE TRUE TRUE
2012 Jul 05
1
reshape2 errors on data frame
I've successfully reformatted data frames from long to wide with reshape2,
but this time I'm getting errors that I want to understand and resolve.
Here's the data frame structure and the results of the melt() and dcast()
functions:
str(waterchem)
'data.frame': 128412 obs. of 8 variables:
$ site : Factor w/ 64 levels "D-1","D-2","D-3",..: 1 1
2012 Jul 10
2
Understanding cenros Error
Before reading water chemistry into a data frame I removed all missing
data. Yet when I try to run cenros() to summarize a specific chemical I get
an error that I do not understand:
with( subset(chem, param=='Ag'), cenros(quant,ceneq1) )
Error in lm.fit(x, y, offset = offset, singular.ok = singular.ok, ...) :
NA/NaN/Inf in 'y'
I would like to learn what I did incorrectly
2012 Aug 07
3
reshape2's dcast() Adds NAs to Data Frame
I need to understand how and why dcast() adds NAs to a data frame that
contained no missing values.
The database table of chemical concentrations has all missing values
removed because they cannot contribute to data analyses. The structure of
the R data frame of these data have no NA values, and neither does the data
frame resulting from applying the reshape2 melt() function to it. However,
2012 Sep 04
1
cenboxplot(): Reporting Limit Twice Correct Concentration
I've gone over the data and do not see my error; the dput() output of the
data frame and the pdf output of cenboxplot() are attached.
The command used:
cenboxplot(sb.t$quant, sb.t$ceneq1, range=1.5, main='Total Recoverable
Antimony', xlab='Pre-Mining Era', ylab='Concentration (log mg/L)')
(on a single line in emacs).
The RL on the plot is drawn at 0.01 rather
2012 Jun 05
0
NADA Applied to my Data
I need a nudge in the right direction to get started using NADA. I bought
Helsel's second addition and am currently reading it; NADA is installed in
R.
My data has been restructured with a couple of awk scripts. The data frame
structure now has a flag if the quantity is censored (ceneq1 column) as well
as a lower and upper limit for censored data. For present purposes, interval
censoring
2012 Aug 22
1
Error in if (n > 0)
I've searched the Web with Google and do not find what might cause this
particular error from an invocation of cenboxplot:
cenboxplot(cu.t$quant, cu.t$ceneq1, cu.t$era, range=1.5, main='Total
Recoverable Copper', ylab='Concentration (mg/L)', xlab='Time Period')
Error in if (n > 0) (1L:n - a)/(n + 1 - 2 * a) else numeric() :
argument is of length zero
I do
2013 Mar 14
2
NADA and cenmle
Hi,
I am using the cenmle function from the NADA package and some of my data
are negative values. As a result the cenmle function will not work and
NaN's are produced. I try to change the distribution to Gaussian, but it
still will not run.
Could somebody please help me with this?
Thanks
--
Shane
[[alternative HTML version deleted]]
2011 Nov 29
5
Why Numeric Values Become Factors in Data Frame
I have a data frame with 1 factor, one date, and 37 numeric values:
str(waterchem)
'data.frame': 3525 obs. of 39 variables:
site : Factor w/ 64 levels "D-1","D-2","D-3",..: 1 1 1 1 1 ...
$ sampdate : Date, format: "2007-12-12" "2008-03-15" ...
$ CO3 : num 1 1 6.7 1 1 1 1 1 1 1 ...
$ HCO3 : num 231 228 118 246
2012 Jun 06
0
R-help Digest, Vol 112, Issue 6
Rich,
The documentation for cenboxplot states that the second argument must be
logical and not integer. the function cenboxplot substitutes synthetic
values for censored values using ros, hence the error message from the ros
method.
I also do not understand how you expect group = 'SO4' to work. It is not
clear that the function will replicate 'SO4' to make a single group.
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 Dec 28
1
subset() missing one factor
The data set (called 'chemdata') has 6 columns (4 factors, 1 date, 1
numeric) and I need to create subsets for each of one of the factors
('stream'). This has worked flawlessly for all but two streams which were
created yesterday.
The command I use to create the subsets is like this:
> rnchH <- subset(chemdata, stream == 'RanchSpgsH', select = c(site, sampdate,
2011 Sep 13
1
ZOO: Learning to apply it to my data
I have read ?zoo but am not sure how to relate the parameters (x,
order.by, frequency, and style) to my data.frame. The structure of the
data.frame is
'data.frame': 11169 obs. of 4 variables:
$ stream : Factor w/ 37 levels "Burns","CIL",..: 1 1 1 1 1 1 1 1 1 1 ...
$ sampdate: Date, format: "1987-07-23" "1987-09-17" ...
$ param : Factor w/
2011 Oct 31
1
reshape2: Lost Values Between melt() and dcast()
Working with 5 subset streams from my source data frame, three of them
successfully call dcast(), but two fail:
jerritt.cast <- dcast(jerritt.melt, site + sampdate ~ param)
Aggregation function missing: defaulting to length
and
winters.cast <- dcast(winters.melt, site + sampdate ~ param)
Aggregation function missing: defaulting to length
Yet both data frames have the values in their
2008 Oct 21
2
Question about glm using R
Good morning,
I am using R to try to model the proportion of burned area in Portugal.
The dependent variable is the proportion. The family used is binomial
and the epsilon would be binary.
I am not able to find the package to be used when the proportion (%) has
to be used in glm. Could someone help me?
I am using normal commands of glm.. for example:
glm_5<- glm(formula=p~Precipitation,
2011 Oct 24
2
Syntax Help for xyplot()
Thanks to David's help I subset my large data set and produced a smaller
one for a single stream and 7 factors of interest. The structure of this
data frame is:
str(burns.tds.anal)
'data.frame': 718 obs. of 4 variables:
$ site : Factor w/ 143 levels "BC-0.5","BC-1",..: 1 1 4 6 4 4 4 5 5 5
$ sampdate: Date, format: "1996-06-02"
2012 Jan 02
1
Creating ZOO Matrix from Data Frame
I believe that I have a basic understanding of zoo and how to use read.zoo
on a text file, What I have not seen in the zoo help files and vignettes is
how to convert a data frame to a zoo matrix for irregular time series
analyses.
An example data frame is structured like this:
str(burns.cast)
'data.frame': 256 obs. of 47 variables:
$ site : Factor w/ 143 levels
2011 Aug 31
1
Correct Syntax for subset.data.frame()
I want to create individual data.frames for each of the 8 param factors in
chemdata. The syntax I tried (based on Teetor's book, page 132) and R's
response are:
> ars <- subset(chemdata, select=c(site,sampdate,param,quant), subset=(param
= "As"))
Error in subset.data.frame(chemdata, select = c(site, sampdate, param, :
'subset' must evaluate to logical
2012 Jan 01
2
Lattice: Understanding How Points Connected by Lines
A data frame has one factor, one date, and one numeric column. When I plot
these using the default pch of the open circle (first attachment),
xyplot(TDS ~ sampdate | she.s, data = sheep.cast, main = 'TDS in Sheep
Creek', ylab = 'Concentration (mg/L)', xlab = 'Time')
I see the higher concentration points toward the right on several panels.
But, when I change to using a
2011 Oct 04
3
How to subset() from data frame using specific rows
I have a data frame called chemdata with this structure:
> str(chemdata)
'data.frame': 14886 obs. of 4 variables:
$ site : Factor w/ 148 levels "BC-0.5","BC-1",..: 104 145 126 115 114 128 124 2 3 3 ...
$ sampdate: Date, format: "1996-12-27" "1996-08-22" ...
$ param : Factor w/ 8 levels "As","Ca","Cl",..: