[ANN] nmap-0.1.0 (narray + mmap = persistant grids)

[Ara.T.Howard]

NAME

nmap (reference ruby class which combines narray and mmap)
na_str (c extension)

REQUIREMENTS

mmap : http://moulon.inra.fr/ruby/mmap.html
narray : http://narray.rubyforge.org/

URIS

http://codeforpeople.com/lib/ruby/nmap/


SYNOPSIS

na_str is designed to allow data sharing between narray object and other ruby
objects. the shared data is that returned by the objects to_s or to_str method
and rb_string_new4. using this technique memory mapped (using guy's mmap
extensions) data can be altered with no explicit io on the users part and
partial changed to numerical grids can occur very quickly and persistently.

the nmap.rb reference impl is a concrete example of this usage and is
included in the distribution.


EXAMPLE USAGE

jib:~/eg/ruby/na_str > cat a.rb
#
# the nmap extension is installed along with na_str
#
require 'nmap'
#
# the NMap ctor interface is similar to NArray's, but a backing file must also
# be specified
#
path, x, y = 'int.data', 3, 4
nmap = NMap.int path, x, y
#
# copy the last row to the first
#
nmap.na[true, 0] = nmap.na[true, 3]
#
# set the last row to be the current time. if you run this a few times you'll
# notice that changes to the narray are automatically written to the to
# backing file via the magic of mmap
#
nmap.na[true, 3] = Time.now.to_i
#
# show the narray
#
p nmap.na


jib:~/eg/ruby/na_str > ruby a.rb
NArray(ref).int(3,4):
[ [ 0, 0, 0 ],
[ 0, 0, 0 ],
[ 0, 0, 0 ],
[ 1151439012, 1151439012, 1151439012 ] ]

jib:~/eg/ruby/na_str > ruby a.rb
NArray(ref).int(3,4):
[ [ 1151439012, 1151439012, 1151439012 ],
[ 0, 0, 0 ],
[ 0, 0, 0 ],
[ 1151439014, 1151439014, 1151439014 ] ]


SPEED

jib:~/eg/ruby/na_str > cat a.rb
#
# reference impl installed with na_str
#
require 'nmap'
#
# setup a narray grid containing 1 gb of ints
#
gb = 2 ** 30
mb = 2 ** 20
sizeof_int = [42].pack('i').size
gig_of_ints = gb / sizeof_int
nmap = NMap.int '1GB', gig_of_ints
#
# set about 1 million of the ints to 42
#
nmap.na[0 .. mb] = 42
#
# show that the data was written
#
p nmap.na[mb - 1]


jib:~/eg/ruby/na_str > time ruby a.rb
42

real 0m0.078s
user 0m0.020s
sys 0m0.020s


jib:~/eg/ruby/na_str > ls -ltar 1GB
-rw-rw-r-- 1 ahoward ahoward 1073741824 Jun 27 14:28 1GB


highly experimental. enjoy.

-a

 

[Joel VanderWerf]

NAME

nmap (reference ruby class which combines narray and mmap)

Ara, have you considered a name that won't get confused with the nmap
utility? Someone might want to write a ruby-nmap for port scanning etc.

 

[ara.t.howard]

Ara, have you considered a name that won't get confused with the nmap
utility? Someone might want to write a ruby-nmap for port scanning etc.

um. no. never heard of that! suggestions?

na_map?

-a

 

[Joel VanderWerf]

um. no. never heard of that! suggestions?

na_map?

amap

num_map

narray_map

array_map

virtual_array

 

[John Mettraux]

amap
...

n-ara-map ?

 

[Tim Pease]

n-ara-map ?

pnarray (sounds like canary but with a 'p')

for persistent narray

TwP

 

[ara.t.howard]

memray?

ohhhh. i like.

maybe

memarray


-a

 

[ara.t.howard]

memray?

or just

marray


-a

 

[Bill Kelly]

or just

marray

Sounds good... "vmarray" is probably too literalist



Regards,

Bill

 

[Phrogz]

ohhhh. i like.

"Meeeemray
All alone, in the moonlight.
I can smile at the old days.
When my tests were not Zen.

I remember
The time I knew not what Narrays were
Let the memray live again"

 

[ara.t.howard]

"Meeeemray
All alone, in the moonlight.
I can smile at the old days.
When my tests were not Zen.

I remember
The time I knew not what Narrays were
Let the memray live again"

LOL!

-a

 

[Daniel Schierbeck]

or just

marray

Well, array -> ary, so:

mary

?


Cheers,
Daniel

 

[Martin DeMello]

Well, array -> ary, so:

mary

mnemmap

martin

 

[Brian Candler]

mnemmap

do dooo, di do-do...

 

[ara.t.howard]

mnemmap

eminmap ?? ;-)

-a

 

[Chris Carter]

eminmap ?? ;-)

-a

eigenmap?

 

[Chad Perrin]

eigenmap?

One of these days, we'll have to name something eigeneigen.

 

[Tim Pease]

One of these days, we'll have to name something eigeneigen.

eigeneigen = lambda {|obj| class << obj; class << self; self; end; end}

Should I make a gem?

TwP

 

[Gary Wright]

One of these days, we'll have to name something eigeneigen.

Here we go eigen.

Gary Wright

 

[Chad Perrin]

eigeneigen = lambda {|obj| class << obj; class << self; self; end; end}

Should I make a gem?

Sure. Make sure you create some documentation.