[plt-dev] Racket web page

This gives me a bunch of errors in addition to the result

Welcome to DrRacket, version 5.0.0.1--2010-05-24(bece17d/g) [3m].
Language: racket; memory limit: 512 MB.
load-handler: expected a `module' declaration for `bernoulli-example'  
in #<path:/Users/matthias/Library/Racket/planet/300/5.0.0.1/cache/ 
williams/science.plt/2/9/examples/bernoulli-example.ss>, but found  
something else
load-handler: expected a `module' declaration for `science-Z-A' in  
#<path:/Users/matthias/Library/Racket/planet/300/5.0.0.1/cache/ 
williams/science.plt/2/9/html/science-Z-A.scm>, but found something else
load-handler: expected a `module' declaration for `control' in #<path:/ 
Users/matthias/Library/Racket/planet/300/5.0.0.1/cache/williams/ 
science.plt/2/9/ode-initval/control.ss>, but found something else
setup-plt: error: during making for <planet>/williams/science.plt/2/9/ 
examples
setup-plt:   load-handler: expected a `module' declaration for  
`bernoulli-example' in #<path:/Users/matthias/Library/Racket/planet/ 
300/5.0.0.1/cache/williams/science.plt/2/9/examples/bernoulli- 
example.ss>, but found something else
setup-plt: error: during making for <planet>/williams/science.plt/2/9/ 
html
setup-plt:   load-handler: expected a `module' declaration for  
`science-Z-A' in #<path:/Users/matthias/Library/Racket/planet/ 
300/5.0.0.1/cache/williams/science.plt/2/9/html/science-Z-A.scm>, but  
found something else
setup-plt: error: during making for <planet>/williams/science.plt/2/9/ 
ode-initval
setup-plt:   load-handler: expected a `module' declaration for  
`control' in #<path:/Users/matthias/Library/Racket/planet/300/5.0.0.1/ 
cache/williams/science.plt/2/9/ode-initval/control.ss>, but found  
something else





On May 24, 2010, at 1:20 PM, John Clements wrote:

> From my computational finance class today, a function that computes  
> (log)mean and (log)stdev for the last 20 years of a stock:
>
> #lang racket
>
> (require net/url (planet williams/science/statistics))
> (define (ticker->url t) (format "http://ichart.finance.yahoo.com/table.csv?s= 
> ~a&a=04&b=24&c=1990&d=04&e=24&f=2010&g=d&ignore=.csv" t))
>
> (define (pair-from-ticker ticker)
>  (let* ([prices
>          (map (lambda (l) (string->number (seventh (regexp-split  
> #rx"," l))))
>               (rest (port->lines (get-pure-port (string->url (ticker- 
> >url ticker))))))]
>         [logdiffs (list->vector (for/list ([p1 (in-list (rest  
> prices))]
>                                            [p2 (in-list prices)])
>                                   (log (/ p2 p1))))])
>    (vector (standard-deviation logdiffs)
>            (mean logdiffs))))
>
> (map pair-from-ticker '("T" "IBM"))
>
>
> ... bummer about the long url.
>
> I'm about to combine this with a web-scraper to get the last 20  
> years of data for every member of the S&P that's been around for 20  
> years, but that *really* won't fit in the box.
>
> John
>
>
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