## localisation : maths

Mar 7, 2006 at 8:23am

# localisation : maths

Hello,

just a simple math question, as, i guess it’s pretty obvious, but i’m
not sure how to make it with max.

So i got a map with a few points on it. There’s a moving one. What’s the
distance between this point and all the other static ones ? What’s the
speed of the moving point ?

best regards

f.e

#24754
Mar 7, 2006 at 9:16am

lets said point A and B
distance A to B is …

AB = [((Ax-Bx)^2)+((Ay-By)^2)]^0.5

and speed is…

S = AB/time

http://en.wikipedia.org/wiki/Pythagorean_theorem

diex

#72089
Mar 7, 2006 at 9:21am

sorry I forget to said that X and Y are your graphic coordinates.
Replace variables with your A and B points coordinates.
Use [expr]

expr [((\$i1-\$i2)^2)+((\$i3-\$i4)^2)]^0.5

byebye

#72090
Mar 7, 2006 at 9:27am

On 7Mar2006, at 9:23, f.e wrote:

> So i got a map with a few points on it. There’s a moving one.
> What’s the distance between this point and all the other static
> ones ? What’s the speed of the moving point ?

Distance is sqrt((x1-x2)*(x1-x2) + (y1-y2)*(y1-y2)). x1/y1 would be
the coordinates of your moving point, x2/y2 would be whichever point
you take as a reference.

“Speed” can mean a couple of different things: velocity as a vector,
absolute magnitude of the vector… I expect in your case you would
simply want the change in distance (as calculated above) divided by
time, giving you pixels/sec.

Hope this helps,
Peter

#72091
Mar 7, 2006 at 10:36am

#72092
Mar 7, 2006 at 1:57pm

knowing that there is nothing as cool as that
in the litter pack it is a joy for me to
recommend you to use

[110.pythagoras]

which you can dl here:

unfortunately i failed to post before peter did;
my friggin OS 9 toast program just chrashed me

when came back to the forum there were two posts

for now i shall overlook that offense.

-slow old 110

#72093
Mar 7, 2006 at 3:05pm

Dear Roman,

If this is an abstraction, could you zip it ?

If this is an external, would you send me the sources in order for me to
compile it for windows ?

best regards

f.e

#72094
Mar 8, 2006 at 12:36am

oops right you is on win. sorry.
you should be able to open toast files on windows,
but the files were lacking extensions anyway.

hope my zip files work for you .. they might need
aladdin app … i have never luck with that kind
of “stuff”.

-eill eill nuns

#72095
Mar 8, 2006 at 12:41am

Quote: f.e wrote on Tue, 07 March 2006 00:23
—————————————————-
> Hello,
>
> just a simple math question, as, i guess it’s pretty obvious, but i’m
> not sure how to make it with max.
>
> So i got a map with a few points on it. There’s a moving one. What’s the
> distance between this point and all the other static ones ? What’s the
> speed of the moving point ?
>

cartopol is my friend in situations like these.

mz

#72096
Mar 8, 2006 at 8:38am

Thank you Roman,

at least i own MacDrive to extract the .bin “original mac file” from the
.zip ;-D

cheers

f.e

#72097
Mar 9, 2006 at 3:19am

Hi all

I’m close to finishing a set of Ambisonic Max/MSP externals for spatialising
sound sources & transforming spatial sound fields (including encoding,
rotating and decoding up to 3rd order in 2-D/3-D layouts). I’m looking for
people to help beta-test them – especially if you’re lucky enough to have
multi-channel speaker arrays lying around… :-)

Let me know if you can. OSX only for now (Mach-O externs).

G

#72098
Mar 9, 2006 at 7:48am

Hi,

I would be interested. I have worked quite a bit on ambisonics in the
past year, trying different approaches, and we are currently planning
to implement modules for dealing with ambisonics in Jamoma
(www.jamoma.org).

I’ve got multichannel layouts laying around, up to 18 speakers.

What license are you planning on releasing the objects according to?

Best,
Trond

#72099
Mar 9, 2006 at 4:37pm

i have made a decoder/encoder too, but only for
weighting … and now i am a bit clueless how
to use the encoder in conjunction with filtering ;)

it is hardly possible for me to read up on the theory
so i will be happy to see some maxmsp patches with examples.

#72100
Mar 9, 2006 at 11:16pm

wakefield wrote:
> I’m close to finishing a set of Ambisonic Max/MSP externals for spatialising
> sound sources & transforming spatial sound fields (including encoding,
> rotating and decoding up to 3rd order in 2-D/3-D layouts). I’m looking for
> people to help beta-test them – especially if you’re lucky enough to have
> multi-channel speaker arrays lying around… :-)
>
> Let me know if you can. OSX only for now (Mach-O externs).

I’d love to…

Stefan

[][] [][][] [][] [][][]
[][][][][][][][][][][][][][][]

Stefan Tiedje
Klanggestalter
Electronic Composition
&
Improvisation

/~~~~~
\ /|() ()|
))))) )| | |( \
/// _/)/ )))))
___/ ///

————————-x—-
–_____———–|———–
–(_|_ —-|—–|—–()—-
– _|_)—-|—–()———–
———-()————x—–

14, Av. Pr. Franklin Roosevelt,
94320 Thiais, France
Phone at CCMIX +33-1-57 42 91 09

#72101
Mar 10, 2006 at 1:04am

Moi aussi!

Cheers,
Gary Lee Nelson
TIMARA Department
Oberlin College
http://www.timara.oberlin.edu/GaryLeeNelson

#72102
Mar 10, 2006 at 6:20am

Hi Graham,

am very interested – moving most of my work to multi-channel now. Am
in-between-cities for the next month, so have some limited access to a
5.1studio at the moment, but thereafter should have a
5.1 system regularly available, possibly more. My background is software
testing, so I’m up for writing decent bug reports etc…

regards,

Mark

#72103
Mar 10, 2006 at 8:27am

http://www.grahamwakefield.net/soft/ambi%7E/index.htm

Max/MSP externals for Ambisonic encoding, rotating and decoding up to 3rd
order for two or three dimensional speaker arrays.

Ambi.encode~ encodes a monophonic source to a specified azimuth and
elevation.

Ambi.encoden~ encodes up to 16 sources to distinct azimuth and elevation
orientations (specified individually or as a list).

Ambi.rotate~ transforms an encoded sound field by rotating around axes
(currently limited to rotations around the Z axis).

Ambi.decode~ decodes an ambisonic encoded sound field to a user-defined
speaker array of up to 16 channels (more can be added by using more than one
ambi.decode~ object). Messages control the speaker layout, global gain,
mono/spatialized balance, and decoding flavour.

More ambi externals/abstractions planned: ambi.decode51~, ambi.mirror~,
ambi.grain~, ambi.oscbank~, ambi.sfplay~, jit.ambi~ etc etc, but may have to
wait for the new SDK since I have no codewarrior ;-)

I’m also trying to figure out how to represent the encoded sound-field as a
deformed sphere in Jitter, to add to the package. Any tips gracefully
appreciated.

I’ve used it here at UCSB’s MAT program on a 16-channel 3-D array and it
sounds good, but your mileage may vary. I’m assuming you already are
familiar with Ambisonic sound field representations; if not, check out:

G

#72104
Mar 10, 2006 at 9:34am

Hi,

interesting… will try.

One thing that for me is important is missing: an ambisonic to
binaural converter external, to listen with headphones.

Good work.

All the best

Alessandro Fogar

#72105
Mar 10, 2006 at 10:40pm

Actually, a HRTF object for MSP would be useful in general…

#72106
Mar 12, 2006 at 6:41pm

> Actually, a HRTF object for MSP would be useful in general…

buffir~?

somebody posted a nice patch to the list with
a set of soundfiles not long ago, that should do this;

> > One thing that for me is important is missing: an ambisonic to
> > binaural converter external, to listen with headphones.

#72107
Mar 12, 2006 at 7:33pm

Indeed buffir~ would be a good candidate, if only it could handle more than
256 points…

#72108

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