similar to: Remove specific rows in a matrix/data.frame

Displaying 20 results from an estimated 13000 matches similar to: "Remove specific rows in a matrix/data.frame"

2012 Jul 18
2
duplicate data between two data frames according to row names
Hi everybody. I'll first explain my problem and what I'm trying to do. Admit this example: I'm working on 5 different weather stations. I have first in one file 3 of these 5 weather stations, containing their data. Here's an example of this file: DF1 <- data.frame(station=c("ST001","ST004","ST005"),data=c(5,2,8)) And my two other stations in
2012 Jul 19
3
Maintaining Column names while writing csv file.
Dear R helpers, I have one trivial problem while writing an output file in csv format. I have two dataframes say df1 and df2 which I am reading from two different csv files. df1 has column names as date, r1, r2, r3 while the dataframe df2 has column names as date, 1w, 2w. (the dates in both the date frames are identical also no of elements in each column are equal say = 10). I merge these
2011 Oct 13
2
how to plot two surfaces with lattice::wireframe
Hi all, I'd like to plot the Real and Imaginary parts of some f(z) as two different surfaces in wireframe (the row/column axes are the real and imag axes). I know I can do it by, roughly speaking, something like plotz <- expand.grid(x={range of Re(z)}, y={range of Im(z), groups=1:2) plotz$func<-c(Re(f(z),Im(f(z)) wireframe(func~x*y,data=plotz,groups=groups) But that seems like a
2010 Sep 03
5
how to get row name of matrix when result is a vector
Hi, the R code: a <- matrix(c(1,5,4,3,7,10,34,4,3,8,6,5,12,17,45,3,2,45,46,47,3,4,22,12,21), nrow=5) rownames(a) <- c("a","b","c","d","e") a a[which(a[,3] < 8), ] a[which(a[,3] < 6), ] produces the following output: > a [,1] [,2] [,3] [,4] [,5] a 1 10 6 3 3 b 5 34 5 2 4 c 4 4 12 45 22 d
2010 Mar 17
3
save data to an R object
Dear R people, Is it possible to save three data sets in an R object and to call each data from this object independently! Regards, Cheba [[alternative HTML version deleted]]
2009 Aug 12
2
Superscripts in axis label
Hi All, I am trying to lable the y-axis on my scatterplot with the following: "Soil moisture content (m3m-3)" I am using the following coding for plotting the graph: plot(soilmoisture~gradientlevel, xlab="Levels of droughting gradient", ylab="Soil moisture content (m3m-3)", bty="l", font.main="2", pch=16, las=1, cex.lab="1.13") I have
2012 Aug 02
6
Polygon shaded area
Hi all, I have two vectors (columns) called "efinal" and "efinal 2". I want to plot them on the same plot and "draw" a shaded area beween the two lines using function polygon I have tried all but I don ?t understand the polygon area, can you help me with examples? plot(efinal,type="l",ylim=range(min(efinal2),
2009 Apr 08
2
Null-Hypothesis
Hello R users, I've used the following help two compare two regression line slopes. Wanted to test if they differ significantly: Hi, I've made a research about how to compare two regression line slopes (of y versus x for 2 groups, "group" being a factor ) using R. I knew the method based on the following statement : t = (b1 - b2) / sb1,b2 where b1 and b2 are the two slope
2011 Oct 10
3
How to test if two C statistics are significantly different?
Hey all, In order to test if a marker is a risk factor, I built two models (using cox proportional hazard model). One model included this marker, and the other is not. Then, I use R package risksetROC to test how much predictive value did the marker add to this model. I get two C statistics by analyzing the linear predictors of the two models into this package. The qustion is How to test if two
2011 Oct 22
7
"Plotting" text?
I noticed that the text() command adds text to a plot. Is there a way to either make the plot blank or add text to a "blank sheet". I would like to "plot" a page that contains just text, no plot lines, labels, etc. Suggestions? Kevin [[alternative HTML version deleted]]
2012 Feb 21
2
Using substitute in nested function calls
Dear List members, I really, like the feature that one can call R functions with mathematical expressions, e.g. curve(x^2, 0, 1) I wonder, how I can construct in a simple way a function like mycurve = function (expr) {...} such that that a call mycurve(x^2) has the same effect as the call curve(x^2, -100,100) Below is some code that works, but it seems much to complicated: it first
2011 Sep 19
3
Replace a for loop with a function
Hi all, I would like to replace the for loop in the code below with a function to improve the speed and to make the script more efficient. The loop creates a vector of integers (x) with the probability of f for each integer. The length of f is variable, but sums to 1. I tried to use a function with optional arguments which did not work. Here is the code: f <- data.matrix(c(0.5,0.15,0.35))
2010 Dec 15
3
selecting certain rows from data frame
Hi, if I have a dataframe such that ID Time  Earn 1        1        10 1        2        50 1        3        68 2        1        40 2        2        78 2        4       88 3        1        50 3        2        60 3        3        98 4        1        33 4        2        48 4        4       58 ..... .... ..... Now if I have to select the all the rows from the data frame which does not
2011 Aug 17
9
too many var in lm
Hello, It might be an easy question but if you have many variables to fit in the lm function, how do you take all without specifying var1+var2+...+var2100 in the terms parameter in response ~ terms? Cheers, Carol
2011 Feb 09
3
Loop in variable names
Hello! I would like to do some tables for several variables and I would like to write a loop that does the table for each variable. I should also point out that my data set has several missing observations and sometimes the observations that are missing are not the same for all my variables. What I would like to do: table(StoreData$CompanyID, !is.na(StoreData$P2))
2011 Jul 28
3
construct a data set
Hi, i want to construct a data set similar to "AirPassengers". Its attributes are following. > attributes(AirPassengers) $tsp [1] 1949.000 1960.917 12.000 $class [1] "ts" How Can I construct a data set similar to it having same class and attributes. Thanks -- Amar Kumar Nandan ?:nandan.amar at gmail.com http://aknandan.co.nr
2011 Mar 14
7
creating character vector
Is there a way to convince R to create a character vector without using the quotes? This works ex1 <- c("first","second") but when I try this it doesn't ext <- as.character(c(first,second)) it complains. I have many variables to put into character vectors so dispensing with the quotes would be useful. Thanks Jim =============================== Dr. Jim Maas
2011 Aug 17
3
Obtaining variable's names from a list of variables
Say I have a list of variables,  listVar <- list(age,sex) I am looking for a way to either 1- create a vector c("age","sex") from it, or 2- get the names one by one in a for loop such as these     a)  for (i in 1:length(listVar)) rownames(result)[i] <- ???     b)  for(i in listVar) print (variable's name) Any help much appreciated. [[alternative HTML version
2011 Apr 27
2
ROCR for combination of markers
Dear list   I have 5 markers that can be used to detect an infection in combination. Could you please advise me how to use functions in ROCR/ other package to produce the ROC curve for a combination of markers?   I have used the following to get ROC statistics for each marker. pred <- prediction(y$marker1, y$infectn) perf <-performance(pred,"tpr","fpr")
2017 Dec 20
1
outlining (highlighting) pixels in ggplot2
I apprecaite the guidance Eik, that works great! I'm also wondering if you have any pointers for how I might stretch the color scale so that the max and min values are the same? Right now, the min is -0.064 and the max is something closer to 0.04. As you can see in what I sent, I tried adding: zmax1 = max(abs(m1)) ggplot(..., autoscale = FALSE, zmin = -1 * zmax1, zmax = zmax1) + ... to