datalorax · phgrosjean · Apr 10, 2026 · Mar 27, 2026 · Mar 30, 2026 · Apr 4, 2026
diff --git a/DESCRIPTION b/DESCRIPTION
@@ -1,6 +1,6 @@
 Package: equatiomatic
 Title: Transform Models into 'LaTeX' Equations
-Version: 0.4.5
+Version: 0.4.6
 Authors@R:
     c(person(given = "Daniel",
              family = "Anderson",

diff --git a/NEWS.md b/NEWS.md
@@ -1,3 +1,9 @@
+# equatiomatic 0.4.6
+
+* Equation for logit glm models now allows for a compact form with `logit_notation = TRUE`. Thanks Michael Friendly for the suggestion.
+
+* `preview_eq()` now can preview lists of equations.
+
 # equatiomatic 0.4.5
 
 * Correction in a bug in `.labels()` that caused incorrect labels for polynomial

diff --git a/R/extract_eq.R b/R/extract_eq.R
@@ -103,6 +103,8 @@
 #' @param se_subscripts Logical. If \code{se_subscripts = TRUE} then the 
 #'   equation will include the standard errors below each coefficient. 
 #'   This is supported for lm and glm models.
+#' @param logit_notation Logical. If \code{TRUE}, then the equation uses a more
+#'   compact notation for a logistic regression.
 #' @param ... Additional arguments (for future development; not currently used).
 #' @export
 #'
@@ -167,6 +169,8 @@
 #' )
 #' mod5 <- glm(out ~ ., data = d, family = binomial(link = "logit"))
 #' extract_eq(mod5, wrap = TRUE)
+#' # More compact logit notation
+#' extract_eq(mod5, wrap = TRUE, logit_notation = TRUE)
 extract_eq <- function(model, intercept = "alpha", greek = "beta",
                        greek_colors = NULL, subscript_colors = NULL,
                        var_colors = NULL, var_subscript_colors = NULL, 
@@ -179,7 +183,7 @@ extract_eq <- function(model, intercept = "alpha", greek = "beta",
                        use_coefs = FALSE, coef_digits = 2,
                        fix_signs = TRUE, font_size = NULL,
                        mean_separate = NULL, return_variances = FALSE,
-                       se_subscripts = FALSE, ...) {
+                       se_subscripts = FALSE, logit_notation = FALSE, ...) {
   UseMethod("extract_eq", model)
 }
 
@@ -201,13 +205,14 @@ extract_eq.default <- function(model, intercept = "alpha", greek = "beta",
                                use_coefs = FALSE, coef_digits = 2,
                                fix_signs = TRUE, font_size = NULL,
                                mean_separate = NULL, return_variances = FALSE, 
-                               se_subscripts = FALSE, ...) {
+                               se_subscripts = FALSE, logit_notation = FALSE,
+                               ...) {
   if (index_factors & use_coefs) {
     stop("Coefficient estimates cannot be returned when factors are indexed.")
   }
 
   lhs <- extract_lhs(model, ital_vars, show_distribution, use_coefs, 
-                     swap_var_names, var_colors)
+    swap_var_names, var_colors, logit_notation = logit_notation)
   rhs <- extract_rhs(model, index_factors)
 
   eq_raw <- create_eq(
@@ -342,7 +347,8 @@ extract_eq.lmerMod <- function(model, intercept = "alpha", greek = "beta",
                                use_coefs = FALSE, coef_digits = 2,
                                fix_signs = TRUE, font_size = NULL,
                                mean_separate = NULL, return_variances = FALSE,
-                               se_subscripts = FALSE, ...) {
+                               se_subscripts = FALSE, logit_notation = FALSE,
+                               ...) {
   if (isTRUE(se_subscripts)) {
     warning("Standard errors are not supported for mixed effects models",
       call. = FALSE
@@ -422,7 +428,8 @@ extract_eq.glmerMod <- function(model, intercept = "alpha", greek = "beta",
                                 use_coefs = FALSE, coef_digits = 2,
                                 fix_signs = TRUE, font_size = NULL,
                                 mean_separate = NULL, return_variances = FALSE,
-                                se_subscripts = FALSE, ...) {
+                                se_subscripts = FALSE, logit_notation = FALSE,
+                                ...) {
   if (!is.null(greek_colors)) {
     warning(
       paste0("Colorization of greek notation not currently ",
@@ -461,7 +468,7 @@ extract_eq.forecast_ARIMA <- function(model, intercept = "alpha", greek = "beta"
                                       use_coefs = FALSE, coef_digits = 2,
                                       fix_signs = TRUE, font_size = NULL,
                                       mean_separate = NULL, return_variances = FALSE,
-                                      se_subscripts = FALSE, ...) {
+                                      se_subscripts = FALSE, logit_notation = FALSE, ...) {
 
   if (isTRUE(se_subscripts)) {
     warning("Standard errors are not supported for mixed effects models",
@@ -620,7 +627,7 @@ extract_eq.model_fit <-
            use_coefs = FALSE, coef_digits = 2,
            fix_signs = TRUE, font_size = NULL,
            mean_separate = NULL, return_variances = FALSE, 
-           se_subscripts = FALSE, ...) {
+           se_subscripts = FALSE, logit_notation = FALSE, ...) {
 
   if ("fit" %in% names(model)) {
     fitted_model <- model$fit
@@ -641,7 +648,7 @@ extract_eq.model_fit <-
       fix_signs = fix_signs, font_size = font_size,
       mean_separate = mean_separate, 
       return_variances = return_variances, 
-      se_subscripts = se_subscripts, ...)  
+      se_subscripts = se_subscripts, logit_notation = logit_notation, ...)  
   } else {
     stop("The 'model' does not appear to be a proper **model_fit** object ",
       "because it does not have a 'fit' component.")
@@ -663,7 +670,7 @@ extract_eq.workflow <-
            use_coefs = FALSE, coef_digits = 2,
            fix_signs = TRUE, font_size = NULL,
            mean_separate = NULL, return_variances = FALSE, 
-           se_subscripts = FALSE, ...) {
+           se_subscripts = FALSE, logit_notation = FALSE, ...) {
 
   if ("fit" %in% names(model)) {
     fitted_stage <- model$fit
@@ -686,7 +693,7 @@ extract_eq.workflow <-
         fix_signs = fix_signs, font_size = font_size,
         mean_separate = mean_separate, 
         return_variances = return_variances, 
-        se_subscripts = se_subscripts, ...) 
+        se_subscripts = se_subscripts, logit_notation = logit_notation, ...) 
     } else {
       stop("The 'model' does not appear to be a proper **workflow** object ",
         "because it does not have a proper 'fit' component.")
@@ -714,7 +721,7 @@ extract_eq.list <- function(model, intercept = "alpha", greek = "beta",
   use_coefs = FALSE, coef_digits = 2,
   fix_signs = TRUE, font_size = NULL,
   mean_separate = NULL, return_variances = FALSE, 
-  se_subscripts = FALSE, ...) {
+  se_subscripts = FALSE, logit_notation = FALSE, ...) {
 
   res <- sapply(model, extract_eq, intercept = intercept, greek = greek,
     greek_colors = greek_colors, subscript_colors = subscript_colors,
@@ -733,7 +740,7 @@ extract_eq.list <- function(model, intercept = "alpha", greek = "beta",
     fix_signs = fix_signs, font_size = font_size,
     mean_separate = mean_separate, 
     return_variances = return_variances, 
-    se_subscripts = se_subscripts, ...)
+    se_subscripts = se_subscripts, logit_notation = logit_notation, ...)
   res <- as.character(res) # Make sure it is a character vector
   names(res) <- names(model)
   class(res) <- c("equation", "character")

diff --git a/R/extract_lhs.R b/R/extract_lhs.R
@@ -22,7 +22,8 @@ extract_lhs <- function(model, ...) {
 #' @noRd
 
 extract_lhs.lm <- function(model, ital_vars, show_distribution, use_coefs,
-                           swap_var_names, var_colors, ...) {
+                           swap_var_names, var_colors, logit_notation = FALSE,
+                           ...) {
 
   check_dots(...)
   lhs <- rownames(attr(model$terms, "factors"))[1]
@@ -67,7 +68,7 @@ extract_lhs.summary.lm <- extract_lhs.lm
 #' @return A character string
 #' @noRd
 extract_lhs.lmerMod <- function(model, ital_vars, use_coefs, swap_var_names,
-                                var_colors, ...) {
+                                var_colors, logit_notation = FALSE,...) {
   check_dots(...)
   lhs <- all.vars(formula(model))[1]
   lhs_nm <- lhs
@@ -99,7 +100,7 @@ extract_lhs.lmerMod <- function(model, ital_vars, use_coefs, swap_var_names,
 #' @return A character string
 #' @noRd
 extract_lhs.glmerMod <- function(model, ital_vars, use_coefs, ...) {
-  extract_lhs.lmerMod(model, ital_vars, use_coefs, ...)
+  extract_lhs.lmerMod(model, ital_vars, use_coefs, logit_notation = FALSE, ...)
 }
 
 #' Extract left-hand side of a glm object
@@ -115,11 +116,14 @@ extract_lhs.glmerMod <- function(model, ital_vars, use_coefs, ...) {
 #' @noRd
 
 extract_lhs.glm <- function(model, ital_vars, show_distribution, use_coefs,
-                            swap_var_names, var_colors,...) {
+swap_var_names, var_colors, logit_notation = FALSE, ...) {
+
   if (show_distribution) {
     if (model$family$family == "binomial") {
+      if (!isFALSE(logit_notation))
+        message("logit_notation = TRUE ignored when show_distribution is TRUE.")
       return(extract_lhs2_binomial(model, ital_vars, use_coefs,
-                                   swap_var_names, var_colors))
+        swap_var_names, var_colors, logit_notation = logit_notation))
     } else {
       message("This distribution is not presently supported; the distribution assumption
       will not be displayed")
@@ -133,7 +137,7 @@ extract_lhs.glm <- function(model, ital_vars, show_distribution, use_coefs,
 
       lhs_escaped <- escape_tex(lhs)
 
-      if(!is.null(var_colors)) {
+      if (!is.null(var_colors)) {
         names(lhs) <- lhs_nm
         names(lhs_escaped) <- lhs_nm
         lhs_escaped <- colorize_terms(var_colors, list(lhs), list(lhs_escaped))
@@ -150,7 +154,7 @@ extract_lhs.glm <- function(model, ital_vars, show_distribution, use_coefs,
   }
   if (model$family$family == "binomial") {
     return(extract_lhs_binomial(model, ital_vars, use_coefs,
-                                swap_var_names, var_colors))
+      swap_var_names, var_colors, logit_notation = logit_notation))
   } else {
     lhs <- all.vars(formula(model))[1]
     lhs_nm <- lhs
@@ -162,7 +166,7 @@ extract_lhs.glm <- function(model, ital_vars, show_distribution, use_coefs,
 
     lhs_escaped <- escape_tex(lhs)
 
-    if(!is.null(var_colors)) {
+    if (!is.null(var_colors)) {
       names(lhs) <- lhs_nm
       names(lhs_escaped) <- lhs_nm
       lhs_escaped <- colorize_terms(var_colors, list(lhs), list(lhs_escaped))
@@ -183,7 +187,8 @@ extract_lhs.glm <- function(model, ital_vars, show_distribution, use_coefs,
 #' @noRd
 
 extract_lhs_binomial <- function(model, ital_vars, use_coefs,
-                                 swap_var_names, var_colors) {
+swap_var_names, var_colors, logit_notation = FALSE) {
+
   outcome <- all.vars(formula(model))[1]
   outcome_nm <- outcome
   names(outcome) <- outcome_nm
@@ -192,15 +197,13 @@ extract_lhs_binomial <- function(model, ital_vars, use_coefs,
     outcome <- swap_names(swap_var_names, outcome)[[1]]
   }
 
+  outcome_escaped <- escape_tex(outcome)
+  outcome_escaped <- add_tex_ital_v(outcome_escaped, ital_vars)
+
   # This returns a 1x1 data.frame
   ss <- model$data[which(model$y == 1)[1], outcome_nm]
-
   # Convert to single character
   ss <- as.character(unlist(ss))
-
-  outcome_escaped <- escape_tex(outcome)
-  outcome_escaped <- add_tex_ital_v(outcome_escaped, ital_vars)
-
   ss_escaped <- escape_tex(ss)
   ss_escaped <- add_tex_ital_v(ss_escaped, ital_vars)
 
@@ -213,29 +216,47 @@ extract_lhs_binomial <- function(model, ital_vars, use_coefs,
     names(ss_escaped) <- outcome_nm
     ss_escaped <- colorize_terms(var_colors, list(outcome), list(ss_escaped))
   }
-
-  if (is.na(ss)) {
-    full_lhs <- paste("P(", outcome_escaped, ")")
+
+  if (isTRUE(logit_notation)) {
+    if (use_coefs) {
+      full_lhs <- paste0(
+        "\\operatorname{logit}\\left[ P(\\hat{",
+        outcome_escaped,
+        "}) \\right]"
+      )
+    } else {
+      full_lhs <- paste0(
+        "\\operatorname{logit}\\left[ P(",
+        outcome_escaped,
+        ") \\right]"
+      )
+    }
   } else {
-    full_lhs <- paste(
-      "P(", outcome_escaped,
-      "=",
-      ss_escaped, ")"
-    )
-  }
-  if (use_coefs) {
-    full_lhs <- add_hat(full_lhs)
+    if (is.na(ss)) {
+      full_lhs <- paste("P(", outcome_escaped, ")")
+    } else {
+      full_lhs <- paste(
+        "P(", outcome_escaped,
+        "=",
+        ss_escaped, ")"
+      )
+    }
+    if (use_coefs) {
+      full_lhs <- add_hat(full_lhs)
+    }
   }
 
-  full_lhs <- modify_lhs_for_link(model, full_lhs)
+  if (!isTRUE(logit_notation))
+    full_lhs <- modify_lhs_for_link(model, full_lhs)
   class(full_lhs) <- c("character", class(model))
   full_lhs
 }
 
 #' @keywords internal
 #' @noRd
 extract_lhs2_binomial <- function(model, ital_vars, use_coefs, swap_var_names,
-                                  var_colors) {
+var_colors, logit_notation = FALSE) {
+
   outcome <- all.vars(formula(model))[1]
   outcome_nm <- outcome
   names(outcome) <- outcome_nm

diff --git a/R/print.R b/R/print.R
@@ -93,7 +93,7 @@ preview_eq <- function(x, ...) {
     stop("Pandoc is not available. Please install it to use this function.",
       call. = FALSE)
 
-  if (!inherits(x, "equation"))
+  if (!inherits(x, c("equation", "list")))
     x <- extract_eq(x)
 
   rmd <- tempfile(fileext = ".Rmd")

diff --git a/TODO.md b/TODO.md
@@ -4,7 +4,7 @@
     is (re)defined here.
 
 - Check the two last tests in test-lmerMod.R that produce different roundings
-    on a silicon processor in macOS. For now these tests are skipped.
+    on several systems, and with R 4.6.0. For now these tests are skipped.
 
 - Implement the Greek characters colorization for `lme4::lmer()` and
     `lme4::glmer()`.

diff --git a/man/extract_eq.Rd b/man/extract_eq.Rd
diff --git a/tests/testthat/_snaps/glm.md b/tests/testthat/_snaps/glm.md
@@ -38,6 +38,36 @@
     \end{aligned}
     $$
 
+# logit_notation works for logistic glm
+
+    Code
+      extract_eq(model_logit, logit_notation = TRUE)
+    Output
+      $$
+      \operatorname{logit}\left[ P(\operatorname{outcome}) \right] = \alpha + \beta_{1}(\operatorname{categorical}_{\operatorname{b}}) + \beta_{2}(\operatorname{categorical}_{\operatorname{c}}) + \beta_{3}(\operatorname{continuous\_1}) + \beta_{4}(\operatorname{continuous\_2})
+      $$
+
+---
+
+    Code
+      extract_eq(model_logit, logit_notation = TRUE, wrap = TRUE)
+    Output
+      $$
+      \begin{aligned}
+      \operatorname{logit}\left[ P(\operatorname{outcome}) \right] &= \alpha + \beta_{1}(\operatorname{categorical}_{\operatorname{b}}) + \beta_{2}(\operatorname{categorical}_{\operatorname{c}}) + \beta_{3}(\operatorname{continuous\_1})\ + \\
+      &\quad \beta_{4}(\operatorname{continuous\_2})
+      \end{aligned}
+      $$
+
+---
+
+    Code
+      extract_eq(model_logit, logit_notation = TRUE, use_coefs = TRUE)
+    Output
+      $$
+      \operatorname{logit}\left[ P(\hat{\operatorname{outcome}}) \right] = 5.33 + 0.33(\operatorname{categorical}_{\operatorname{b}}) - 0.12(\operatorname{categorical}_{\operatorname{c}}) - 0.06(\operatorname{continuous\_1}) + 0.01(\operatorname{continuous\_2})
+      $$
+
 # Renaming Variables works
 
     $$