Quote from P4U7 :

Any who, what do you guys/girls think about the April teaser posted on the main page dated Apr. 3rd, 2006 22:00, about the following comment;

"We have also been experimenting with another interesting feature as well... "

Is this F1 car the interesting feature they we have been told about, or is this still going to be a even bigger surprise..? would love to hear your comments.

i think there is more...honestly i thought that in one year, eric's work would be much more (from what screenshots reveal)...but maybe he did more but just keeping for S3 content.
about the "interesting feature" i think it will be revealed at the release time, maybe is something related to racing (like the "take over" feature) or maybe night racing or dynamic daytime...who knows?

Quote from Hyperactive :

PS. I saw a dream that Scawen send me an SMS saying that the patch will be released on 19th of this month. Because it's a dream it can't be wrong

tonight i dreamt that the patch was released today in the very early morning, but only on a mirror (i dreamt the link also...), so as soon i woke up i checked it up (the dream was so realistic...), but nothing... i believe they will release it today, but if they do it in the late afternoon when everyone's home, the server/mirrors bandwidth will not be enough.

Quote from TRM.13 :

The oval is a very good filter of semipilots, they stay there, and we stay away from the oval in real racing

unfortunately i think it's the contrary: after few ovals noobs think they can handle fo8, so they go to the first fo8 server to ruin your race, then when they realize they cannot do even few meters with fo8, they go ruin some gtr races, then they ruin some tbo races...and then they think "maybe it's better to practice oval a bit more" and story repeats...

Quote from Madman_CZ :

agree with tristan totaly, no way am i taking my BRAND SPANKING new f1 to the oval.... think my first time it will be westhill reversed

my experience with lfs oval is just almost none...only once i spectate to see who in this world could do ovals...surprisingly oval is always full

Quote from wheeler :

or just make a (tyre) chicane in it like the GP of USA should have got last year

yeah, that should force noobs to try to learn driving instead of doing oval

Quote from tristancliffe :

There's NO WAY ON EARTH that my F1 car is going anywhere near an oval. I'm planning on going somewhere where talent is required and people that can drive are likely to be.

i hope devs remove the oval definately...

Quote from Bogey Jammer :

I have not finished to study all the last posts yet but to answer to the question: FFT is quite useless for me now. I wanted to use it to help me to setup my suspensions. I thought I would adapt suspension frequency to track frequency but it was wrong since track frequency is not clearly defined, and suspension frequency depends on the car.

However, FFT is useful for something, but I don't know what, it seems that it's not very helpful...

well my suggestion is always the same: don't apply fft over th whole track, but divide the track into "interesting" segments i.e. each corner, segments with bumps, etc. then examine both time and frequency graphs the reason in doing this apart from possible mathematical reasons, is that you will deal with less information (divide et impera), so it may be easier to find caracteristics/behaviour on segments of track, if so then it will be up to your decision how to find the compromise that satisfies you.

as i said before, i'm not able to interpret the graphs you showed (doing fft over the whole track), so maybe you could at least give a try at doing a segmented analisys, it shouldn't hurt

Quote from Shotglass :

im not entirely sure about this but my gut feeling says yes and no
on the topic of saturation ... yes youre right this sort of comes down to my point that the wheel should always stay in contact with the ground only in the other direction which i forgot to consider as it should never happen if the setup is fit for the track
on the bias point id say no since lfs doesnt simulate progressive springs (yet) therefore the spectrum shouldnt change with biasing

ive just thought of another thing i hadnt considered properly yet which is the time variance induced by the 2-way dampers ... obviously the different damping constants create 2 different transfer functions (tf)
to get rid of this youd either have to
1) use no dampers at all therefore youll get the pure tf of the spring and can then derive the 2 damped tfs from that
2) use the same values for both compression and bump damping and after 2 test runs with your desired values for bump and compression youll have both tfs of the time variant system
3) only analyze blocks of data where the suspension is traveling in one direction ... this will of course lead to poor spectral resolution

point (2) is the only completely correct, but is insufficient because it is a simplified sysem which is rarely used by lfs, to better model we should write down equations, but i surely don't want to do this

Quote :

i could argue that the spectrum estimation problem is a measurement problem though since as you cant improve spectral resolution by higher sampling frequencies the only way to do so is by longer measurements and therefore by sacrificing temporal resolution

i think we can argue for years about that, but for the forum sake we better consider it OT...

Quote :

frankly i dont know enough about quantum physics to see if i could actually prove that both problems are the same so lets settle this with calling them dual

well i'm not an expert too, but i had to study enough (too much for my taste ) of it in several courses, but i had to study much about measurement (i'm an electronic engineer) where heisenberg was a key point...but obviously could be that my teachings were biased and so am i.

what comes in my mind now is a phrase that one of my professors was used to say:"the art of mathematics is giving same names to different things", well i never agreed with that, but i think it fits to our discussion

so i will follow your suggestion: let's end calling it "dual"

PS i'm still awaiting that the thread starter will answer to our doubt..."suspension" or "bumps"?

Quote from the_angry_angel :

Good idea batman!

lol thanks!
but why batman?

...at least ...batgirl

what is really needed is "fuel setups" (independent from car setup) to save fuel strategy for each particular combo car/track/laps

Quote from Shotglass :

steering angle ... interesting point ... but it doesnt actually change the suspension geometry (or at least not in ways which have a effect on suspension frequencies)

i cannot find a better way to explain wat i mean, than the following example (i hope): think of steering enugh to bring suspension near saturation...now if you hit a bump, the suspension saturates/clips an thus you have as output a spectrum with infinite bandwidth caused by non linearity. well this is extreme, but the concept is that you are introducing an "unknown" force/signal that is biasing the system and such bias is time variant, so also the system will be time variant. imo.

Quote :

actually stationarity is the wrong word since it is a property of random processes ... for systems the right word would be time variant and a suspension that basically floating in mid air is obviously different from one with gorund contact
matter of fact the suspension is inherently time variant though as it has different damping depending on the direction of travel

yes it is clearly so, the fact is that in the last years (lol sounds like i'm an old mummy ) i work on a totally different field, so i always feel there is something important that i don't remember about this topic

Quote :

hmmm i thought the question was "how to analyse suspension transfer functions

let's hope the topic starter clarify us wat he wanted to know

Quote :

actually this isnt what heisenberg is about its a very common false explaination though

well my example was the problem that brought to the heisenberg relationship and may seem not clear how the example fit into that, he found the relation because during his studies about quantistic theory he faced the problem of measuring at the same time speed and position of electrons. on the other hand the problem of spectral estimation is given basically by removing any "infinite" value from the formulas given by theory such as integral/series and mostly by approximating algorithms to calculate it, so it's mostrly "numeric" precision...i understand you point of view, but i don't agree and one thing that i think "prooves" it is that error forumulas and relationships about spectrum estimation are expressed in terms of part of integrals you give away or terms of series you truncated and not by the heisenberg formula, another thing: one problem is "measurement", another is "estimation/approximation" the two problems may be considered "dual" perhaps but they are generated from different causes anyway all of this may be considered one of the mathematical/phisical things that have different toughts, i believe none of us will change point of view about that, but surely it isn't a problem

Last edited by Honey, Fri 23 Dec 2005, 13:43.

Quote from Bogey Jammer :

Very impressive :cry:

FFT is more hardcore than I though lol

happy to impress you, but...you could also clarify our "uncertainity": do you want to find track bump frequencies or the suspension transfer function (ie the spectrum), or both?

if you don't stop us by answering that, we can continue for years... :P

Quote from Shotglass :

imho its stationary under the asumption that the wheel doesnt lift from the ground
oh and if im not mistaken the transfer function is the systems spectrum (ie the fourier transform of the systems impulse response)

IMHO to be stationary it would be required to lock the steer at 0° (and thus a straight road), about wheel that lift from ground, i'm not sure if ti could be the reason for non-stationary, but sounds pretty reasonable.
about the definition of "transfer function" you are right, i remembered wrong: the time domain function is the "impulsive response", my mistake

Quote :

depends on what you want to do with it
for system identification (of time invariant systems) you want a large number of nodes along the frequency axis therefore youll use a large number of samples

since the question that originated this thread was basically "how to find track bumps frequencies", i think only small time windows can reveal that.
it's like the human speech (which is clearly non-stationary), if you want to know the spectrum of the letter "i" inside the word "stationary" you surely don't calculate the spectrum of the word but you will apply a proper time window that surronds the "i" on the time axis and then calculate the spectrum only on that time window

Quote :

for analysis of instationary proceses however (like used for adaptive prediction in (speech) coders or for utilizing psychoaccustic effects like in mp3 coding) you want shorter sets of samples (during which the process can be considered stationary) to get a better resolution in the time domain (this has to be paid with a loss in spectral resolution though ...

basically is what i said before too, but i think specral resolution should not be an issue for suspension and track analisys

Quote :

basicaly spectral and time-domain resolution are interchangeable and have a joint upper bound much like the minimal uncertainty (to be considered the inverse of resolution) in impulse and position measurements have a joint lower bound (heisenberg))

this is totally different, the spectral estimation is caused by implied limits of mathematical definitions/functions against reality. the minimum uncertainity (the heisenberg principle) is a conseguence of the fact that measuring "something" implies perturbing the system and thus it changes the system itself, so the measured value is actually the measure of the whole system "original system to be measured" + "measuring instrument".

Quote :

im not sure what you mean with that question

basically i was wondering if someone (except the devs) knows more about the lfs suspension model...

Last edited by Honey, Thu 22 Dec 2005, 20:29.

Quote from sil3ntwar :

there is a reason 6 wheelers are now banned in formula one.

...and what is this reason?

anyway i think 6 wheelers would be fun and very interesting to drive, anyway they represent a unique piece of history of formula one

Quote from Shotglass :

the spectrum of the springs deflection is actually the multiplication of the excitations and the systems sprectra (and to be exhaustive also the spectrum of the window you use for the fft)

you are correct about all points, except that IIRC the spectrum of the output is equal to the product of the spectrum of the "transfer function" and the spectrum of the input signal if and only if the system is stationary and i think it is not.

IMO fft should be applied to small periods of time to be meaningful, don't you think? ...i'm asking it to you because you seem to have fresh in mind the theory

ps as the lfs suspension model is linear, shouldn't be an impulse the spectrum fo the suspension transfer function?

Quote from 5th Earth :

But then that begs the question, why do the graphs have multiple peaks, above and below the natural frequency?

as i said before i believe that the suspension output, as a signal, cannot be considered stationary (statistically speaking), so it's "meaningless".
what should be done IMO is calculating fft over short periods of time...short enough that the suspension signal can be considered stationary within it.
then plotting all the fft results in a graph of the spectrum against time, this helps finding the track-bumps frequency...

using math is cool, but it should be applied under the theorem's hypotesis to be meaningful, which is not this case IMO.

no i only meant short period of time, if u go straight it helps finding bump frequency of the track, i only intended that if suspensions are not solicitated, the spectrum of the output will be (teoretically) zero, because it has zero input...only this

the "merceds test" should help finding compression and rebound frequencies in a single step.

if you did an fft over the whole track, the graph is (as it seems to me) meaningless, because you are outside of "stationariety" of the signal...well i am assuming that the suspension response it is not over a whole track, i think is better you consider many fft over small time windows, enough small for the suspension response to be considered "stationary"...also i think the update time of the phisic model should be important for the aliasing issue, but as long we assume (as i think) the lfs phisic model is good, the i believe it is fast enough to avoid aliasing.

so my hint is to try to fft only a small time...maybe the crossing of the chicane or much better the test wich mercedes class A failed: a sudden steer and countersteer on a plain straight. hope it helps

Scawen, thanks for clarifing us (without compromising yourself ) the issues you will work on and to not expect anything before christmas, but i always have a question: on what aspects is Eric working on? ...or at least is he working on something in particular like a fresh new track/config/car or he is working on improving graphics of present lfs content?

...if you prefer to not answer/compromise yourself, i will understand but i'm curious, soi just tryied asking ?

thanks! now i think i know all i need to know to backup

thanks guys! ...i took a look into the lfs files and i see three "cfg" files in the main folder, they seem to be related to graphics and controller preferences, should i consider those too?

thanks!

can you tell me what are the config files anyway? i'm kinda paranoid about backups and similar things

i want to transfer LFS to a more powerful PC,so i'm guessing what is best between the following two options:

- copy the current LFS folder to the new PC -> do i need to LOCK the account before copying and unlock again after copying? or the unlocked state will preserve with the different hardware?

- unzip a new copy of LFS to the new PC, unlock it and copy only configuration files and setups -> what are the config files that contain all graphic/game/credits/AI-training/whatever ?

i would prefer the seconf option, but except for setups i don't have any clue where all other informations are stored. Eventually i can lose AI-training because i don't care it very much, but if i can copy it, it's better.

thanks!

i'm not sure if understood weel the japanese problem, but following Scawen suggestion while reading this post i made a very small program to quick fix it.

it is an application that resides into the tray of the windows taskbar (right click to exit or suspend/activate it), it does only the following thing: when you press CRTL+SHIFT+0 (<- this is the zero key, it is not an O like otello), it sends the T keystroke to the focused application, if needed i can dynamically activate it only for LFS but let's first see if it works...

PS i do not have the Q patch installed, so i can't reproduce it

Quote from qba_m :

Thanks for patch, I really hope there will be a progess raport with info at the main site (about other game aspects, like physics etc. - if anything like that has been updated)
PS sorry for OT, but how can I change "demo racer" to "S2 licensed" under my nick?

it will automatically update when you will buy the S2 license.