[plt-scheme] Re: Where can I find the rocket-s.jpg image of "How to Design Programs/2e: Prolog, Section 2?"

From: Benjamin L.Russell (DekuDekuplex at Yahoo.com)
Date: Mon Aug 18 03:15:12 EDT 2008

On Mon, 18 Aug 2008 15:24:33 +0900, Benjamin L.Russell
<DekuDekuplex at Yahoo.com> wrote:

>While trying to follow along "How to Design Programs/2e: Prolog,
>Section 2" (see
>http://www.ccs.neu.edu/home/matthias/HtDP/Prologue/book-Z-H-4.html), I
>got stuck in trying to insert the rocket-s.jpg image; viz.:
>
>> One important library -- world.ss -- supports operations for computing the width and height of an image:
>>
>>(* (image-width <rocket-s.jpg image> )
>>   (image-height <rocket-s.jpg image> ))
>>
>>Once you have added a library to your program, clicking Run gives you
>>
>>    1200 
>
>I was unable to find this image just by going to the "Insert" ->
>"Insert Image..." menu item, and when I finally right-clicked on the
>image in the browser, then clicked on "Save Image As...," it saved as
>"rocket-s.jpg," but then executing the above function in the
>Definitions Window returned the following value in the Interactions
>Window:
>
>> 1176
>
>This is not what the text specifies.  How should I insert the image so
>that I get "1200" as the result of executing the above function?

After searching on the Internet, I discovered that the above
rocket-s.jpg image was available at the following site:

/trunk/larceny_src/lib/TeachPacks/rocket-s.jpg -- The Larceny Project
-- Trac:
https://trac.ccs.neu.edu/trac/larceny/browser/trunk/larceny_src/lib/TeachPacks/rocket-s.jpg?rev=3939

However, using this image with the above function still returned 1176,
instead of 1200.  Also, it seems strange that I should need either to
download the rocket-s.jpg image from the Web page or to search for it
on the Internet in order to find it; the book should be self-contained
with respect to using images.

Is there something terribly obvious that I am missing about inserting
this particular image so that the above function returns 1200?

-- Benjamin L. Russell



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