Posts by Carlos Cinelli • 16,826 points
232 posts
- 
		2 votes1 answer449 viewsQ: Build of Sublime Text 2 gives different result than ipython on the command lineI’m trying to migrate to Sublime Text 2 and do everything without leaving the program. Before I ran a script with the following line: from scipy.stats import beta, bernoulli, gaussian_kde In the… 
- 
		8 votes3 answers1784 viewsA: How to format a table (data.frame) with pdf publishing quality (latex) in R?A package that I think is fantastic is the tables. It is very flexible. For example, arranging the tabela in three different ways: library(tables) tabela1 <-… 
- 
		6 votes1 answer829 viewsQ: R workflow: strategies to organize a data analysis projectBased on this question from the SOEN, ask: What strategies do you recommend to organize a data analysis project on R? The project usually involves the following steps (not necessarily in that… 
- 
		9 votes3 answers1784 viewsQ: How to format a table (data.frame) with pdf publishing quality (latex) in R?Suppose the following table: tabela <- structure(list(Sexo = structure(c(1L, 1L, 2L, 2L), .Label = c("Homem", "Mulher"), class = "factor"), Grupo = structure(c(1L, 2L, 1L, 2L), .Label = c("A",… 
- 
		5 votes3 answers2755 viewsA: How to assign the results of a function that returns a list of objects?The solution that I found simpler and more interesting was to define another binary operator (such as,%<-% signaling a modification of the <- ) apply the assign in multiple arguments with the… 
- 
		8 votes1 answer2292 viewsA: How to create objects (variables) with different names within a loop?You can use the function assign for that reason. set.seed(1) for (i in 1:3){ nome <- paste0("dados", i) assign(nome, runif(10,1, 20)) } The first part nome <- paste0("dados", i) creates the… 
- 
		9 votes1 answer339 viewsA: How to declare constants in RYou can use the function lockBinding: For example: pi <- base::pi lockBinding("pi", globalenv()) This will lock the variable pi in the constant base::pi internal in the global Environment. So if… 
- 
		6 votes2 answers4567 viewsA: How to turn a string into Date format in R?An interesting package is the lubridate (CRAN). In your case you will use the function mdy() (Month, day, year), and say that the date is in English: library(lubridate) dados$DataAno <-… 
- 
		3 votes3 answers3281 viewsA: Sublime Text 2 - python error message /usr/bin/python: can’t find '__main__' module in ''In general this problem can be solved by saving the script before running it. 
- 
		3 votes3 answers3281 viewsQ: Sublime Text 2 - python error message /usr/bin/python: can’t find '__main__' module in ''Using the cmd+B (Tools -> Build) in Sublime Text 2, the following error message appears: /usr/bin/python: can't find '__main__' module in '' How to solve this?… 
- 
		16 votes2 answers4769 viewsQ: Apply, sapply, mapply, lapply, vapply,rapply, tapply, replicate, Aggregate, by and correlates in R. When and how to use?What is the difference between the functions apply, sapply, mapply, lapply, vapply, rapply, tapply, replicate, aggregate, by and correlates in the R? When and how to use each of them? There are… 
- 
		6 votes2 answers2443 viewsA: How to smooth a curve in RAnother very quick way to adjust a smoothed line is to use the smoothed line itself geom_smooth of ggplot2: library(ggplot2) ggplot(data = df, aes(x, y)) + scale_x_log10() + geom_point() +… 
- 
		20 votes5 answers12797 viewsA: How to consolidate (aggregate or group) the values in a database?Hadley recently created the dplyr, a much faster version with more intuitive syntax than the plyr. (links for the cran and to the announcement on Rstudio’s blog) In the dplyr would look like this… 
- 
		5 votes1 answer648 viewsA: How to read a table missing or poorly configured elements?One way to solve the problem is by putting the argument fill=TRUE in the read.table: tabela <- read.table(text=texto, fill=TRUE) tabela V1 V2 V3 1 a b c 2 e f 3 g h i… 
- 
		5 votes1 answer648 viewsQ: How to read a table missing or poorly configured elements?Suppose a text table like the following: texto <- "a b c e f g h i" When I use the read.table command, the following error occurs:: tabela <- read.table(text=texto) Error in scan(file, what,… 
- 
		7 votes3 answers3287 viewsQ: How to put the regression equation on a graph?On another question saw how to put the regression line on a graph. But, how to put the regression equation in the graph? For example: Or… 
- 
		3 votes1 answer5683 viewsA: How to run a R script from the Windows command line?You can use the argument BATCH of R CMD or the Rscript: R CMD BATCH teste.R or Rscript teste.R 
- 
		4 votes2 answers355 viewsA: Negative variance in R? Floating point error propagationComplementing Marcos Banik’s response. A floating point number of type double (64 bits) can be roughly summarized in 3 parts: Floating point type double: signal (1bit), order of magnitude (11 bits)… 
- 
		11 votes2 answers355 viewsQ: Negative variance in R? Floating point error propagationSuppose the following formula to calculate the variance: variancia <- function(x) { n <- length(x) (1/(n^2-n))*(n*(sum(x^2))-(sum(x)^2)) } Note that it is equivalent to the function var in… 
- 
		12 votes4 answers1519 viewsQ: Why is 0.1 + 0.05 not equal to 0.15? What solutions can be used in R?In the R: 0.1+0.05 == 0.15 [1] FALSE Why does this happen? How to get around the situation (functions and packages to handle floating points)? Editing: This other question already contains general… 
- 
		4 votes1 answer4682 viewsA: How to create a Plot with 2 superimposed histograms?It is possible to do with the base functions by placing semi-transparent colors: h1<-hist(grupo1) h2<- hist(grupo2) plot(h1, col=rgb(0,0,1,1/4), main = "Histogramas", xlab = "x", ylim… 
- 
		7 votes2 answers637 viewsA: How to make a conditional y~x graph for each data.frame factor?One way is to use the function coplot: coplot(y~x |w, data=dados) It is also possible to do with the ggplot2 using facet_wrap: library(ggplot2) ggplot(data=dados, aes(y=y, x=x))+… 
- 
		8 votes2 answers637 viewsQ: How to make a conditional y~x graph for each data.frame factor?Suppose a data.frame like the following: set.seed(1) dados <- data.frame(w=rep(c("A", "B", "C", "D"), 50), y= rnorm(200), x=rnorm(200), stringsAsFactors=FALSE) How to create a chart y~x separated… 
- 
		5 votes3 answers530 viewsQ: How to select all data.frame variables at once for a regression?Suppose the following data.frame: set.seed(1) dados <- data.frame(y=rnorm(100), x1=rnorm(100), x2=rnorm(100), x3=rnorm(100), x4=rnorm(100)) If I want to run a y regression against x1...xn, I can… 
- 
		6 votes1 answer3442 viewsA: How to plot the estimated logistic regression modelWith the function plot base, you would have to sort the data before: plot(saldo,y) lines(data$saldo[order(data$saldo)], default.glm$fitted[order(data$saldo)], type="l", col="red") With the gpplot2… 
- 
		8 votes4 answers8280 viewsA: How to put the regression line on a graph?You can use the function abline along with coef to extract model coefficients and plot the line: plot(y~x) abline(coef(modelo))… 
- 
		9 votes4 answers8280 viewsQ: How to put the regression line on a graph?Suppose a linear regression model like the following: set.seed(1) x <- rnorm(100) y <- rnorm(100) + 2*x +10 modelo <- lm(y~x) If I plot y against x, how do I include the regression line in… 
- 
		2 votes2 answers195 viewsA: How to load all functions from a folder?It might be interesting to create a function that reads files from an arbitrary folder, so you can reuse the code several times. To make the code cleaner, you can use the sapply instead of a loop… 
- 
		5 votes3 answers17265 viewsA: How to sort a column-by-column data.frame in R?You can use the function order. To sort the date.frame by column z in descending order, for example: dados[order(dados$z, decreasing=TRUE),] w x y z 4 B C 1.5952808 0.7383247 3 A D -0.8356286… 
- 
		6 votes3 answers17265 viewsQ: How to sort a column-by-column data.frame in R?Suppose a data.frame with numerical values and strings: set.seed(1) dados <- data.frame(w=rep(c("A", "B"), 2), x= rep(c("D", "C"), 2), y= rnorm(4), z=rnorm(4), stringsAsFactors=FALSE) dados w x y… 
- 
		6 votes6 answers31940 viewsA: How to remove a data.frame column in R?There are many ways to do this. The simplest is to assign NULL to the column, for example to remove the column x: dados$x <- NULL head(dados) y z w 1 -0.6264538 0.4094018 0.8936737 2 0.1836433… ranswered Carlos Cinelli 16,826
- 
		7 votes6 answers31940 viewsQ: How to remove a data.frame column in R?Suppose a generic date.frame, such as: set.seed(1) dados <- data.frame(y=rnorm(100), x= rnorm(100), z=rnorm(100), w=rnorm(100)) head(dados) y x z w 1 -0.6264538 -0.62036668 0.4094018 0.8936737 2… rasked Carlos Cinelli 16,826