add dot-test.R; edit vignette; bump pkg v0.9.91

DESCRIPTION

@@ -2,8 +2,8 @@ Package: matlib
 Type: Package
 Title: Matrix Functions for Teaching and Learning Linear Algebra and
     Multivariate Statistics
-Version: 0.9.9
-Date: 2024-07-30
+Version: 0.9.91
+Date: 2024-08-24
 Authors@R: c(person(given = "Michael", family = "Friendly", 
                     role=c("aut", "cre"), email="[email protected]",
                     comment=c(ORCID="0000-0002-3237-0941")),

dev/dot-test.R

@@ -0,0 +1,54 @@
+# Test using dot() for matrix mult
+
+numericDimensions <- matlib:::numericDimensions
+updateWrapper <- matlib:::updateWrapper
+parenthesize <- matlib:::parenthesize
+
+`%*%.latexMatrix` <- function(x, y){
+  if (!inherits(y, "latexMatrix")){
+    stop(deparse(substitute(y)),
+         " is not of class 'latexMatrix'")
+  }
+  numericDimensions(x)
+  numericDimensions(y)
+  X <- getBody(x)
+  Y <- getBody(y)
+  dimX <- dim(X)
+  dimY <- dim(Y)
+  if (dimX[2] != dimY[1]){
+    stop('matricies are not conformable for multiplication')
+  }
+
+  Z <- matrix("", nrow(X), ncol(Y))
+  for (i in 1:nrow(X)){
+    for (j in 1:ncol(Y)){
+      for (k in 1:ncol(X)){
+        Z[i, j] <- dot(X[i, ], Y[, j])
+      }
+    }
+  }
+  result <- latexMatrix(Z)
+  result <- updateWrapper(result, getWrapper(x))
+  result$dim <- dim(Z)
+  result
+}
+
+if(FALSE) {
+  (A <- latexMatrix(matrix(c(1, -3, 0, 1), 2, 2)))
+  (B <- latexMatrix(matrix(c(5, 3, -1, 4), 2, 2)))
+  (C <- latexMatrix(symbol="c", 2, 2))
+  (D <- latexMatrix(symbol="d", 2, 2))
+
+  A %*% B
+
+  as.double(A)
+  as.double(B)
+  as.double(A) %*% as.double(B)
+
+  A %*% C
+  A %*% (B - C)
+  A %*% -B
+  (A - 2*D) %*% B
+
+  A %*% solve(B)
+}

vignettes/latex-equations.Rmd

@@ -261,9 +261,33 @@ If the elements of a matrix are valid R variable names, then it is also possible
 as.double(-2*M, locals=c(a=1, b=0, c=-2, d=-4, e=7, f=-1, g=0, h=4, i=6))
 ```
 
-### Transpose and matrix products
+### Matrix products and transpose
 
-The transpose, `t()`, and matrix product, `%*%` of `"latexMatrix"` objects are similarly straightforward. This directly transposes the matrix, as opposed to superscript notation,
+The product of two matrices is given by `%*%` for `"latexMatrix"` objects.
+
+
+```{r product1, results='asis'}
+A %*% B
+```
+
+To get the numeric result evaluated, use `as.double()` and perform ordinary
+matrix multiplication:
+
+```{r product2, results='asis'}
+as.double(A) %*% as.double(B) |> latexMatrix()
+```
+
+The LaTeX symbol for multiplication is a centered dot, `\\cdot` ($\cdot$), by default.
+This can be changed by changing `options(latexMultSymbol)`,
+e.g, to use the $\times$ symbol instead, use:
+
+```{r multSymbol, eval=FALSE}
+options(latexMultSymbol = "\\times")
+```
+
+
+The transpose, `t()` of `"latexMatrix"` 
+objects is similarly straightforward. This directly transposes the matrix, as opposed to superscript notation,
 $\mathbf{D}^\top$ or $\mathbf{D}^\prime$ which is implicit.
 
 ```{r transpose}