From 3d53ab464839be6672e21546e67eb174e4718302 Mon Sep 17 00:00:00 2001
From: Michael Friendly <friendly@yorku.ca>
Date: Sun, 4 Aug 2024 12:46:40 -0400
Subject: [PATCH] fix import in matrix2latex

---
 R/matrix2latex.R               |  1 +
 man/symbolicMatrix.Rd          |  7 ++++++-
 vignettes/linear-equations.Rmd | 10 +++++-----
 3 files changed, 12 insertions(+), 6 deletions(-)

diff --git a/R/matrix2latex.R b/R/matrix2latex.R
index c551cb9e..8ab5f004 100644
--- a/R/matrix2latex.R
+++ b/R/matrix2latex.R
@@ -28,6 +28,7 @@
 #' @param ... additional arguments passed to \code{xtable::xtableMatharray()}
 #' @importFrom xtable xtableMatharray
 #' @importFrom dplyr case_when
+#' @importFrom utils capture.output
 #' @author Phil Chalmers
 #' @export
 #' @examples
diff --git a/man/symbolicMatrix.Rd b/man/symbolicMatrix.Rd
index 211bfa88..4611673d 100644
--- a/man/symbolicMatrix.Rd
+++ b/man/symbolicMatrix.Rd
@@ -23,7 +23,8 @@ symbolicMatrix(
 \item{symbol}{name for matrix elements, character string. For LaTeX symbols,
 the backslash must be doubled because it is an escape character in R.
 That is, you must use  \code{symbol = "\\\\beta"} to get \eqn{\beta}. Alternatively, this can be an
-R matrix object, containing LaTeX code for the elements.}
+R matrix object, containing LaTeX code for the elements. For a row or column vector, use
+\code{matrix(..., nrow=1)} or \code{matrix(..., ncol=1)}}
 
 \item{nrow}{Number of rows, a single character representing rows symbolically, or an integer, generating
 that many rows.}
@@ -170,6 +171,10 @@ symbolicMatrix("\\\\beta", comma=TRUE, exponent="-1")
 symbolicMatrix("\\\\beta", comma=TRUE, transpose=TRUE)
 symbolicMatrix("\\\\beta", comma=TRUE, exponent="-1", transpose=TRUE)
 
+# for a row/column vector, wrap in matrix()
+symbolicMatrix(matrix(LETTERS[1:4], nrow=1))
+symbolicMatrix(matrix(LETTERS[1:4], ncol=1))
+
 # represent the SVD, X = U D V'  symbolically
 X <- symbolicMatrix("x", "n", "p")
 U <- symbolicMatrix("u", "n", "k")
diff --git a/vignettes/linear-equations.Rmd b/vignettes/linear-equations.Rmd
index 5f1c8b14..032cdbd4 100644
--- a/vignettes/linear-equations.Rmd
+++ b/vignettes/linear-equations.Rmd
@@ -106,7 +106,7 @@ all.equal( R(A), R(cbind(A,b)) )  # consistent?
 ```
 You can see this in the result of reducing $\mathbf{A} | \mathbf{b}$ to echelon form, where the
 last row indicates the inconsistency.
-```{r}
+```{r echelon}
 echelon(A, b)
 ```
 `Solve()` shows this more explicitly:
@@ -116,7 +116,7 @@ Solve(A, b, fractions=TRUE)
 
 
 An approximate solution is sometimes available using a generalized inverse.
-```{r}
+```{r ginv}
 x <- MASS::ginv(A) %*% b
 x
 ```
@@ -124,7 +124,7 @@ x
 
 Plot the equations. You can see that each pair of equations has a solution,
 but all three do not have a common, consistent solution.
-```{r}
+```{r plotEqn4}
 par(mar=c(4,4,0,0)+.1)
 plotEqn(A,b, xlim=c(-2, 4))
 points(x[1], x[2], pch=15)
@@ -139,7 +139,7 @@ have a unique solution if all planes intersect in a point.
 
 ### Three consistent equations
 
-```{r}
+```{r three-eqn}
 A <- matrix(c(2, 1, -1,
              -3, -1, 2,
              -2,  1, 2), 3, 3, byrow=TRUE)
@@ -171,7 +171,7 @@ echelon(A, b, verbose=TRUE, fractions=TRUE)
 
 Plot them.  `plotEqn3d` uses `rgl` for 3D graphics.  If you rotate the figure, you'll see an orientation
 where all three planes intersect at the solution point, $\mathbf{x} = (2, 3, -1)$ 
-```{r plotEqn1, webgl=TRUE}
+```{r plotEqn3, webgl=TRUE}
 plotEqn3d(A,b, xlim=c(0,4), ylim=c(0,4))
 ```