From 8ac05ad90a77942573929ab1d853e6a6f54ba097 Mon Sep 17 00:00:00 2001
From: jverzani <jverzani@gmail.com>
Date: Fri, 28 Jul 2023 14:09:32 -0400
Subject: [PATCH] edits; parameterized surface

---
 quarto/index.qmd            | 2 +-
 quarto/misc/quick_notes.qmd | 9 +++------
 2 files changed, 4 insertions(+), 7 deletions(-)

diff --git a/quarto/index.qmd b/quarto/index.qmd
index 82f1554..6a62d70 100644
--- a/quarto/index.qmd
+++ b/quarto/index.qmd
@@ -71,7 +71,7 @@ books visit <https://quarto.org/docs/books>.
 These notes may be compiled into a `pdf` file through Quarto. As the result is rather large, we do not provide that file for download. For the interested reader, downloading the repository, instantiating the environment, and running `quarto` to render to `pdf` in the `quarto` subdirectory should produce that file (after some time).
 
 To *contribute* -- say by suggesting addition topics, correcting a
-mistake, or fixing a typo -- click the "Edit this page" link and join the list of [contributors](https://github.com/jverzani/CalculusWithJuliaNotes.jl/graphs/contributors). Thanks to all contributors and a special thanks to `@fangliu-tju` for their careful proofreading.
+mistake, or fixing a typo -- click the "Edit this page" link and join the list of [contributors](https://github.com/jverzani/CalculusWithJuliaNotes.jl/graphs/contributors). Thanks to all contributors and a *very* special thanks to `@fangliu-tju` for their careful and most-appreciated proofreading.
 
 ----
 
diff --git a/quarto/misc/quick_notes.qmd b/quarto/misc/quick_notes.qmd
index 1d4d41b..06fc853 100644
--- a/quarto/misc/quick_notes.qmd
+++ b/quarto/misc/quick_notes.qmd
@@ -23,7 +23,6 @@ The `Julia` packages loaded below are all loaded when the `CalculusWithJulia` pa
 
 A `Julia` package is loaded with the `using` command:
 
-
 ```{julia}
 using LinearAlgebra
 ```
@@ -455,6 +454,7 @@ This should be contrasted to the case when both `xs` and `ys` are (column) vecto
 
 
 ```{julia}
+#| error: true
 g.(xs, [4,5])
 ```
 
@@ -710,10 +710,7 @@ implicit_plot(f)
 ### Plotting a parameterized surface $f:R^2 \rightarrow R^3$
 
 
-The `pyplot` (and `plotly`) backends allow plotting of parameterized surfaces.
-
-
-The low-level `surface(xs,ys,zs)` is used, and can be specified directly as follows:
+The `pyplot` (and `plotly`) backends allow plotting of parameterized surfaces. The low-level `surface(xs,ys,zs)` is used, as illustrated here.
 
 
 ```{julia}
@@ -723,7 +720,7 @@ Y(theta, phi) = sin(phi)*sin(theta)
 Z(theta, phi) = cos(phi)
 thetas = range(0, pi/4, length=20)
 phis = range(0, pi, length=20)
-surface(X.(thetas, phis'), Y.(thetas, phis'), Z.(thetas, phis'))
+# surface(X.(thetas, phis'), Y.(thetas, phis'), Z.(thetas, phis'))
 ```
 
 ### Plotting a vector field $F:R^2 \rightarrow R^2$.