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Questions tagged [r-formula]

In R language formula objects store symbolic representations of variables. They are produced with a tilde `~` operator and are most often used for specifying statistical models. Use with the [r] tag

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Use of ~ (tilde) in R programming Language

I saw in a tutorial about regression modeling the following command: myFormula <- Species ~ Sepal.Length + Sepal.Width + Petal.Length + Petal.Width What exactly does this command do, and what is the role of ~ (tilde) in the command?
Ankita
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Formula with dynamic number of variables

Suppose, there is some data.frame foo_data_frame and one wants to find regression of the target column Y by some others columns. For that purpose usualy some formula and model are used. For example: linear_model <- lm(Y ~ FACTOR_NAME_1 +…
Max
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How to convert R formula to text?

I have trouble working with formula as with text. What I'm trying to do is to concatenate the formula to the title of the graph. However, when I try to work with the formula as with text, I fail: model <- lm(celkem ~ rok + mesic) formula(model) #…
Tomas
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What does the R formula y~1 mean?

I was reading the documentation on R Formula, and trying to figure out how to work with depmix (from the depmixS4 package). Now, in the documentation of depmixS4, sample formula tends to be something like y ~ 1. For simple case like y ~ x, it is…
Antony
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short formula call for many variables when building a model

I am trying to build a regression model with lm(...). My dataset has lots of features( >50). I do not want to write my code as: lm(output ~ feature1 + feature2 + feature3 + ... + feature70) I was wondering what is the short hand notation to write…
iinception
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Error in terms.formula(formula) : '.' in formula and no 'data' argument

I'm tring to use neuralnet for prediction. Create some X: x <- cbind(seq(1, 50, 1), seq(51, 100, 1)) Create Y: y <- x[,1]*x[,2] Give them a names colnames(x) <- c('x1', 'x2') names(y) <- 'y' Make data.frame: dt <- data.frame(x, y) And now, I got…
luckyi
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extract variables in formula from a data frame

I have a formula that contains some terms and a data frame (the output of an earlier model.frame() call) that contains all of those terms and some more. I want the subset of the model frame that contains only the variables that appear in the…
Ben Bolker
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Formulas in user-defined functions in R

Formulas are a very useful feature of R's statistical and graphical functions. Like everyone, I am a user of these functions. However, I have never written a function that takes a formula object as an argument. I was wondering if someone could help…
gappy
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How can I replace one term in an R formula with two?

I have something along the lines of y ~ x + z And I would like to transform it to y ~ x_part1 + x_part2 + z More generally, I would like to have a function that takes a formula and returns that formula with all terms that match "^x$" replaced by…
rcorty
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Condition ( | ) in R formula

I found this pdf on R formulas and I am not able to figure out how the | works (see the table on the second page). Furthermore, I could not find any explanation on the web. It appears from time to time in lists for possible formula symbols but…
Alex
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Use of Tilde (~) and period (.) in R

I'm going over looping with tidyverse and purrr using Hadley's R4DS book and am a little confused as to the exact usage of the tilde ~ symbol and period symbol. So when writing for loops, or using map(), instead of writing out function(), it appears…
Kevin Lee
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What does the ( | ) syntax mean in an R formula?

I am following a tutorial and came across the following syntax: # assume 'S' is the name of the subjects column # assume 'X1' is the name of the first factor column # assume 'X2' is the name of the second factor column # assume 'X3' is the name of…
Null Salad
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R substitute(), to substitute values in expression, is adding unnecessary quotes

I am trying to update a formula for a linear model in R, based on names of variables that I have stored in an array. I am using substitute() for that and the code is as follows. var = 'a' covar = c('b', 'c') covar = paste(c(var, covar), collapse = '…
Sapiens
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R function with formula return has large memory imprint

I have a function that fits a model which I call many times with the same big matrix (creating different formula inside each time). However, it seems that R saves copies of the data I use along the way, and so my memory explodes. A simple deletion…
tmrlvi
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How to make index for R formula?

I am trying to index some components in a R formula such like var<-c("x1", "x2", "x3") for (i in var) as.formula(i/x4) But it always come with an error: Error in i/x4 : non-numeric argument to binary operator May somebody know how to make it…
David Z
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