In fact, I updated the data frame package to be able to read the CSV file
directly, without having to process it, so the example now becomes:
#lang racket
(require data-frame)
(define df (df-read/csv "worldcities.csv" #:quoted-numbers? #t))
(define ((is-city? name) v)
(equal? (vector-ref v
The next snapshot build (available in 18 hours or so at
pre.racket-lang.org) includes a `#:custodian` optional argument to
`ffi-lib`. Probably you want `#:custodian (current-custodian)`, which
will unload the foreign library for a program run in DrRacket in
reaction to "Kill" or "Run".
Beware
That database is simple enough to use directly, not sure if it needs a
separate package:
#lang racket
(require data-frame)
;; The worldcities.csv file has all values quoted, so df-read/csv reads them
;; all as strings. Convert a series to numbers.
(define (->numeric df series)
That sounds great! I would love to take advantage of it when it becomes
available.
Thanks,
Chris
On Fri, Sep 6, 2019 at 7:09 AM Matthew Flatt wrote:
> There's still no mechanism to unload a DLL.
>
> For a long time, it wasn't practical to try to unload a DLL, because
> the finalization
Regarding the discussion of tests expected to fail, and moving
expected-fail tests to different directories, I wonder whether you'd
prefer using an expected-fail annotation per test case.
An annotation seems useful for my own work, and lightweight, but I don't
know about core Racket
Section 1.1 mentions PLT. Is this obsolete? It is at least confusing
or someone who does not know Racket history.
Section 2.2 Always Test
It should mention that when you formulate a test you should test the
test *before* you modify the code. At present the warning about an
inadequate test
Hi
Has something changed with transparency of structs?
I find the following:
#lang racket/base
(module a racket/base
(define inspector (make-inspector))
(define-values (descr constr pred acc mut)
(make-struct-type 's #f 2 0 #f '() inspector #f '(0)))
(define an-s (constr 'monkey
Josh Rubin wrote on 9/6/19 1:36 PM:
Google Earth (still available as a desktop application) uses
*Keyhole Markup Language* (KML) is an XML-based *markup language*
designed to annotate and overlay visualizations on various
two-dimensional, Web-based online maps or three-dimensional Earth
The recent talk about maps made me interested in thematic maps - for example
hiking maps
A map of the counties in Ohio, distorted so the area of each county
is proportional to population.
Google Earth (still available as a desktop application) uses
*Keyhole Markup Language* (KML) is an
Perhaps I just don’t know how to search the racket docs correctly, but IIUC
there’s no support for Streams in the current TR implementation? I just want to
use stream-cons, empty-stream, stream-first, and stream-rest. I guess the easy
workaround is just to use thunks to roll my own stream, but
Last week on HN, a non-student was complaining about having to increase
DrRacket's memory limit 3 times while they were playing with it, so I
pointed out that DrRacket was designed for new students, and suggested
that maybe that memory limit was a good thing for new students.
One of frequent
On Fri, Sep 06, 2019 at 02:49:45PM +0100, Stephen De Gabrielle wrote:
> LOL
> 128k ! I remember dreaming I had 128K when I was on a 16 K machine.
Well, that 128K was a big omprovement on the machine I *first* tried
implementing Lisp on -- an IBM 1620 with 40,000 decimal digits of
memory.
LOL
128k ! I remember dreaming I had 128K when I was on a 16 K machine.
Recently had to change my limit to 1024 MB...
S.
On Fri, 6 Sep 2019 at 14:41, Hendrik Boom wrote:
> I just noticed DrRacket telling me
> Language: racket, with debugging ; memory limit: 128 MB
> immediatey reminding
I just noticed DrRacket telling me
Language: racket, with debugging ; memory limit: 128 MB
immediatey reminding me of the 128 K that was available on the first
Lisp system I got any actual use from -- one I implemented myself on an
IBM 360/65. Back then there were rumours that some IBM
There's still no mechanism to unload a DLL.
For a long time, it wasn't practical to try to unload a DLL, because
the finalization mechanisms were too asynchronous --- making it
difficult to detect the point where the DLL would no longer be
referenced and could be unloaded safely. But support for
There's a small free database here too:
https://simplemaps.com/data/world-cities
I started writing a simple query system for it this morning (csv->rktd,
then just list of assoc operations).
On Fri, Sep 6, 2019 at 1:35 PM Sage Gerard wrote:
> Would geonames help?
> http://www.geonames.org/
>
>
Would geonames help?
http://www.geonames.org/
Original Message
On Sep 6, 2019, 8:28 AM, Hendrik Boom wrote:
> On Thu, Sep 05, 2019 at 10:42:01PM -0700, Alex Harsanyi wrote:
> ...
>>
>> >
>> > A package containing a database of the positions of the major cities and
>> >
On Thu, Sep 05, 2019 at 10:42:01PM -0700, Alex Harsanyi wrote:
...
>
> >
> > A package containing a database of the positions of the major cities and
> > countries would be nice too :)
> >
>
>
> A general facility able to resolve location names to GPS coordinates would
> be a lot of work, and
Wow, thank you!
Robby
On Thu, Sep 5, 2019 at 11:00 PM Alex Harsanyi
wrote:
>
>
> On Wednesday, September 4, 2019 at 7:50:19 PM UTC+8, Stephen De Gabrielle
> wrote:
>>
>> Dr Racket is amazing. Need to a demo of this and plot side by side.
>>
>
> I can do better than just put a plot and a map
That is awesome -
How you make your videos? - I like the annotations.
Kind regards
Stephen
On Friday, September 6, 2019 at 4:59:56 AM UTC+1, Alex Harsanyi wrote:
>
>
>
> On Wednesday, September 4, 2019 at 7:50:19 PM UTC+8, Stephen De Gabrielle
> wrote:
>>
>> Dr Racket is amazing. Need to a
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