Displaying 20 results from an estimated 20000 matches similar to: "ifelse to speed up loop?"
2012 Jan 19
3
Establishing groups using something other than ifelse()
Hello all,
This is one of those "Is there a better way to do this questions". Say
I have a dataframe (df) with a grouping variable (z). This is my base
data. Now I know that there is a higher order level of grouping that
exist for my group variable. So what I want to do is create a new
column that express that higher order level of grouping based on
values in the sub-group (z in this
2012 Nov 15
4
using ifelse to remove NA's from specific columns of a data frame containing strings and numbers
Hi everyone,
I have a data frame one of whose columns is a character vector and the rest
are numeric, and in debugging a script, I noticed that an ifelse call seems
to be coercing the character column to a numeric column, and producing
unintended values as a result. Roughly, here's what I tried to do:
df: a data frame with, say, the first column as a character column and the
second and
2006 Nov 21
2
using nested ifelse and rowSums to create new variable?
Dear R-help community,
If I have a data.frame df as follows:
> df
x1 x2 x3 x4 x5 x6
1 5 5 1 1 2 1
2 5 5 5 5 1 5
3 1 5 5 5 5 5
4 5 5 1 4 5 5
5 5 1 5 2 4 1
6 5 1 5 4 5 1
7 5 1 5 4 4 5
8 5 1 1 1 1 5
9 1 5 1 1 2 5
10 5 1 5 4 5 5
11 1 5 5 2 1 1
12 5 5 5 4 4 1
13 1 5 1 4 4 1
14 1 1 5 4 5 5
15 1 5 5 4
2013 May 13
2
reduce three columns to one with the colnames
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2012 Oct 11
2
Repeating a series of commands
I'm trying to figure out how to repeat a series of commands in R and have the
outputs added to a dataframe after each iteration.
My code starts this way...
a<-read.csv("File1.csv")
b<-read.csv("File2.csv")
2009 Jan 19
1
ifelse help?
I am having a hard time understanding what is happening with ifelse.
Let me illustrate:
h <- numeric(5)
p <- 1:5
j <- floor(j)
x <- 1:1000
ifelse(h == 0, x[j+2], 1:5)
[1] 2 3 4 5 6
My question is, "shouldn't this be retruning 25 numbers?" It seems that the ifelse should check 5 values of h for zero. For each of the 5 values I am thinking it should return an array of 5
2012 Oct 15
2
fit a "threshold" function with nls
I am trying to model a dependent variable as a threshold function of
my independent variable.
What I mean is that I want to fit different intercepts to y following 2
breakpoints, but with fixed slopes.
I am trying to do this with using ifelse statements in the nls function.
Perhaps, this is not an appropriate approach.
I have created a very simple example to illustrate what I am trying to do.
2005 May 02
1
newbie ifelse matrix question
Hi all,
I have time series data in a matrix format 20 rows x 205 columns and have been trying to replace outliers with NA. My first column contains the outliers threshold (3 Standard deviations) for each row - here's a bit of the first row
sd3 V1 V2 V3 V4 V5 V6 V7 V8 V9
1 13.03267 1797157 75 84 58 -1.958649 0.048775 2.056198 8.063622
2011 Dec 13
4
Keep sourcing when there is an error
Hello,
I want to know if there is any way to avoid source() stopping when there
is an error.
Here is the content of my Main.R script:
source("~/R/source/Constructor1.R") # Object1 should be constructed
ifelse(exists("Object1"), # It's an S4 object
print("Object1 exists"), # I can't avoid using 'validity'
2016 Aug 15
2
ifelse() woes ... can we agree on a ifelse2() ?
On Fri, Aug 12, 2016 at 11:31 AM, Hadley Wickham <h.wickham at gmail.com> wrote:
>> >> One possibility would also be to consider a "numbers-only" or
>> >> rather "same type"-only {e.g., would also work for characters}
>> >> version.
>>
>> > I don't know what you mean by these.
>>
>> In the
2013 Jun 14
2
significance testing for the difference in the ratio of means
I have a question regarding significance testing for the difference in the
ratio of means.
The data consists of a control and a test group, each with and without
treatment. I am interested in testing if the treatment has a significantly
different effect (say, in terms of fold-activation) on the test group
compared to the control.
The form of the data with arbitrary n and not assuming equal
2009 Jan 29
4
Text in a character vector to indicate "ifelse" argument
Hello
I have a data set that looks like this;
> b2
dato chr status PRRSvac
PRRSsanVac PRRSsanDk PRRSdk
33 2007-12-03 090432 R?d SPF
34 2007-02-09 090432 R?d SPF+sanDK
35 2002-12-17 090432 R?d SPF+DK
36 2002-11-27 090432 R?d SPF+sanDK
37 2002-07-23
2012 Jul 03
1
remove loop which compares row i to row i-1
I would like to remove a loop to speed up my code.
I want to remove a loop which references the last row.
In general I want to a remove a loop which looks something like this:
for 2 to number of rows in a matrix do{
if indextrow-1 is < currentIndexRow then do something.
}
My R code:
for (i in 2:length(tUnitsort$Hour)){
ifelse(tUnitsort[i,4]>=tUnitsort[i-1,4],(tempMC
2004 Nov 23
2
IFELSE across large array?
Dear all,
As our previous email did not get any response, we try again with a
reformulated question!
We are trying to do something which needs an efficient loop over a huge
array, possibly functions such as apply and related (tapply,
lapply...?), but can't really understand syntax and examples in
practice...i.e. cant' make it work.
to be more specific:
we are trying to apply a mask
2010 Feb 05
2
ifelse on a series of rows for multiple criteria
Dear all,
I am attempting to perform a calculation which counts the number of positive (or negative) values based on the sample mean (on a per-row basis). If the mean is>0 then only positive values should be counted, and if the mean is <0 then only negative values should be counted. In cases where the mean is equal to zero, the value -99999 should be returned.
The following is an example
2013 Mar 23
4
Converting a character vector to numeric
Hello again,
Let say I have following vector:
Vec <- c("0.0365780769", "(1.09738648244378)", "(0.812507787221523)",
"0.5778069963", "(0.452456601362355)", "-1.8900812605", "-1.8716093762",
"0.0055217041", "-0.4769192333", "-2.4133018880")
Now I want to convert this vector to numeric vector. I
2016 Nov 15
2
ifelse() woes ... can we agree on a ifelse2() ?
All,
Martin: Thanks for this and all the other things you are doing to both
drive R forward and engage more with the community about things like this.
Apologies for missing this discussion the first time it came around and if
anything here has already been brought up, but I wonder what exactly you
mean when you want recycling behavior.
Specifically, based on an unrelated discussion with Henrik
2012 May 31
3
How can I get this function to work?
Hello All,
Can anyone tell help me understand why the function below doesn't work and how I can fix it? Below are some sample data, some code that works on individual rows of the data, and my attempt to translate that code into a function. My hope is to get the function working and then to apply it to the larger data frame using ddply() from the plyr package or possibly some other approach.
2012 May 25
4
Hash Table - Select and Change Data iniside Matrix
Hi,
Here i have been a matrix like this,
*NAME AGE PALCE TRUE/FALSE*
ABC 20 INDIA
XYZ 30 FRANCE
PQR 40 USA
MNO 30 KENIYA
DEF 25 AUSTRALIA
Here,* TRUE/FALSE* Column containing empty values.
So my requirement what is , need to change all the *TRUE/FALSE *column value
into "*TRUE*" where *AGE =
2009 Oct 24
2
ifelse
When I run this code from an R-script:
ddd = 360 + round ( atan2(-u,-v) / d2r )
print(class(ddd))
print(ddd)
ifelse ( ddd>360, ddd-360, ddd )
print(ddd)
I get this output:
[1] "numeric"
[1] 461 213 238 249 251
[1] 461 213 238 249 251
Why does ifelse not change the 461 to 101?
I recreated the vector ddd and ran the same ifelse
code