Dear list, I've tried several times to wrap my head around the Design library, without much success. It does some really nice things, but I'm often uncomfortable because I don't understand exactly what it's doing. Anyway, one thing I really like is the latex.ols() function, which converts an R linear model formula to a LaTeX equation.
So, I started writing a latex.lm() function (not actually using classes at this point, I just named it that for consistency). This turned out to be easy enough for simple cases (see code below), but now I'm wondering a) if anyone knows of existing functions that do this (again, for lm() models, I know I'm reinventing the wheel in as far as the Design library goes), or if not, b) if anyone has suggestions for improving the function below. Thanks, Ista ### Function to create LaTeX formula from lm() model. Needs amsmath package in LaTeX. ### latex.lm <- function(object, file="", math.env=c("$","$"), estimates="none", abbreviate = TRUE, abbrev.length=8, digits=3) { # Get and format IV names co <- c("Int", names(object$coefficients)[-1]) co.n <- gsub("p.*)", "", co) if(abbreviate == TRUE) { co.n <- abbreviate(gsub("p.*)", "", co), minlength=abbrev.length) } # Get and format DV m.y <- strsplit((as.character(object$call[2])), " ~ ")[[1]][1] # Write coefficent labels b.x <- paste("\\beta_{", co.n ,"}", sep="") # Write error term e <- "\\epsilon_i" # Format coefficint x variable terms m.x <- sub("}Int","}", paste(b.x, co.n, " + ", sep="", collapse="")) # If inline estimates convert coefficient labels to values if(estimates == "inline") { m.x <- sub("Int", "", paste(round(object$coefficients,digits=digits), co.n, " + ", sep="", collapse="")) m.x <- gsub("\\+ \\-", "-", m.x) } # Format regression equation eqn <- gsub(":", " \\\\\\times ", paste(math.env[1], m.y, " = ", m.x, e, sep="")) # Write the opening math mode tag and the model cat(eqn, file=file) # If separae estimates format estimates and write them below the model if(estimates == "separate") { est <- gsub(":", " \\\\\\times ", paste(b.x, " = ", round(object$coefficients, digits=digits), ", ", sep="", collapse="")) cat(", \\\\ \n \\text{where }", substr(est, 1, (nchar(est)-2)), file=file) } # Write the closing math mode tag cat(math.env[2], "\n", file=file) } # END latex.lm Xvar1 <- rnorm(20) Xvar2 <- rnorm(20) Xvar3 <- factor(rep(c("A","B"),10)) Y.var <- rnorm(20) D <- data.frame(Xvar1, Xvar2, Xvar3, Y.var) x1 <- lm(Y.var ~ pol(Xvar1, 3) + Xvar2*Xvar3, data=D) latex.lm(x1) -- Ista Zahn Graduate student University of Rochester Department of Clinical and Social Psychology http://yourpsyche.org ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.