Displaying 20 results from an estimated 1000 matches similar to: "NADA Applied to my Data"
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.
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 Aug 07
3
NADA Package: Referencing Data Frame Columns
The sample data sets that come with the NADA package are limited to one or
two variables and a censored measurement indicator column. I try to mimic
examples using my data but keep missing the target.
My water chemistry data is available in two formats: long (as seen in a
database table) and wide (as seen in a spreadsheet). The two structures are:
str(chem)
'data.frame': 65349 obs. of
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 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
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 Aug 15
1
NADA package/cenboxplot() method: maximum censored percentage
One set of data has censored (less-than detection limits) water chemistry
concentrations for 80-100% of all observations. My initial trial-and-error
attempts to apply the cenboxplot() method suggests that it has an upper
limit to the percentage of censored observations. I do not see this limit in
Dennis Helsel's second edition.
Has anyone experience plotting censored data and can provide
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 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"
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
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
2011 Nov 02
2
Proper Syntax for Logical Subset in Subset()
I have measured values for 47 chemicals in a stream. After processing
the original data frame through reshape2, the recast data frame has this
structure:
'data.frame': 256 obs. of 47 variables:
$ site : Factor w/ 143 levels "BC-0.5","BC-1",..: 1 1 1 2 2 2 2 2 2 2
...
$ sampdate : Date, format: "1996-04-19" "1996-05-21" ...
$ Acid :
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
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 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 Sep 22
3
Bivariate Scatter Plots with Lattice
Data frame has this structure:
'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/ 8 levels "As","Ca","Cl",..: 1 1 1 1 1 1 1 1 1 1 ...
$ quant : num 0.01 0.01 0.01 0.01
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 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 Oct 23
1
Understanding lattice barchart() display
I've a data frame with this structure:
'data.frame': 1987 obs. of 11 variables:
$ site : Factor w/ 24 levels "B(W)","BC-1",..: 1 1 2 2 2 1 1 1 ...
$ sampdate : Date, format: "2000-07-18" "2000-07-18" ...
$ tclass : Factor w/ 8 levels "Annelida","Arachnida",..: 1 5 5 5 5 ...
$ torder : Factor