Hello

SÃ¸ren,Perhaps there was a miscommunication. Yes, time is sampled at uniform

intervals, like you pointed out. What I’m talking about is in parameter study.

Let me give an example with pseudo-code.Main = { … Study = { …

AnyVar R = 1.0; }; // end study}; // end mainparameterStudy = {…AnyDesVar P =

{ Val = Main.Study.R; Min = 0.9*Val; Max = 1.1*Val;}nSteps =

{3};Every time I run the parameter study, the analysis would be run 3 times, for

R values in {0.9, 1.0, 1.1}. This is because the closed interval [0.9*1.0,*

1.11.0] is sampled at equal intervals of 0.1. These are the same values every

time I run.The set {0.95, 1.0, 1.05} is also uniformly distributed. It just

doesn’t include the extreme points. Put another way, sampling at equal intervals

leads to a uniform distribution, but not all uniform distributions have samples

at equal intervals. I’ve tried to give a more set theoretic explanation further

below, if it would help.The point I’m trying to get across is that every time I

run a parameter study simulation, I should be able to obtain different sequences

for DesVar that are not necessarily sampled at the same equal intervals of

(Max-Min) / (nSteps-1).Sincerely,-Venn-----------------------------------In

terms of set the theory,Let U be the set of all uniformly distributed 3-tuples

from the closed interval [0.9, 1.1], i.e, U = { (x1,x2,x3) | 0< = x1, x2, x3

<= 1.1 and (x1, x2, x3) are uniformly distributed } Note that U is an

uncountably infinite set.Let e be the 3-tuple that is equally distributed from

the same closed interval , as is the case with Anybody, i.e., e = (0.9, 1.0,

1.1);Clearly, {e } is only a subset of U. In fact e is but a trivial member of

U .Additionally, we could see that e belongs to E where E is the (uncountably

infinite) set of all equally distributed 3-tuples from the same closed interval

[0.9, 1.1]. E is also a subset of U. Example: (0.9, 1.01, 1.1) belongs to U

but not to E, while (0.93, 0.96, 0.99) and (0.9, 0.95, 1.0) belong to E and

in turn to U. To: anyscript@yahoogroups.comFrom: support@anybodytech.comDate:

Thu, 22 Feb 2007 09:13:04 +0000Subject: [anyscript] Re: Parameter Study

```
Hi Venn
```

I am not sure i understand you compleately, i will try to explain how

it works.

The property nStep simply tell how many step to use

tStart is the time value when the analysis starts

tEnd is the time value when it ends.

Example1:

nStep=3;

tEnd=1;

tStart=0;

The analysis will calulate for the following time values: t={0,0.5,1}

Example2:

nStep=5;

tEnd=3;

tStart=1;

The analysis will calulate for the following time values: t=

{1,1.5,2,2.5,3}

So there is not any propability in play here, it is a uniform

distribution of time values between tStart and tEnd divided into

nSteps

Best regards

SÃ¸ren

– In anyscript@yahoogroups.com, Vengateswaran Ravichandran

<vennjr@…> wrote:

>

>

> SÃ¸ren,Using a dR term is a much more elegant way of doing what I

was trying to do. Thanks for your help. I’ll implement it.Now, about

Question 1b.You are right that the default values generated by

Anybody would fit a uniform distribution. But it is not the only

uniform distribution I could generate.If I obtain 11 numbers randomly

generated in the interval [0,10], such that the resulting numbers are

uniformly distributed, I agree that the numbers {0, 1, 2, …, 10}

would fit the bill. But uniform distribution means that any number in

the interval [0,11] is equally likely. In other words the probability

for any number (within [0,11]) to be chosen is equal to the

probability of any other number being chosen. However, when I choose

{0, 1,…, 10} every time I try to chose a set of 11 numbers, the

probability is not the same. Simply put, I’m trying to differentiate

between when the intervals between numbers chosen are equal and when

the probability of any number being chosen are equal. I don’t know if

I made sense… if I did not, please let me know and I’ll try to

explain better.Sincerely,-VennTo: anyscript@…: support@…: Tue, 20

Feb 2007 09:17:46 +0000Subject: [anyscript] Re: Parameter Study

>

>

>

>

>

>

>

>

>

>

>

>

>

>

>

>

>

>

> Hi Venn

>

> I have taken a look at your file, you are right what you are trying

> to do there is not possible. The reason is that you are trying to

> assign Radius using both a design variable and an expression which

is

> not independent, this can not be done, the system would not known

> which of them to use. A possible hack could be if you use the

normal

> espression for Radius and then in that expresion add the value of

> your design variable. Then you would have the normal radius and the

> parameter study could do changes to this value

>

> it would look something like this:

>

> dR=0; //from your paramter study make a lnk to this varaible

>

> Radius = sqrt((.node1.sRel[0]-…P1[0])^2 + (.node1.sRel[1]-…P1[1])

> ^2 + (.node1.sRel[2]-…P1[2])^2)+ dR;

>

> In this way you can change the radius using your design variable

and

> if it is zero you have not made any change.

>

> About question 1a i have made a small example which should

illustrate

> this, it has been uploaded as “ParamterStudyWithSelectedValues.any”

>

> About question 1b this what AnyBody will do by default, if you

> specify a nStep={10} and your design variable has a min =0 and max=

1

> it will distribute the 10 steps uniformly between 0 and 1.

>

> Best regards

> SÃ¸ren

>

>

> — In anyscript@yahoogroups.com, Vengateswaran Ravichandran

> <vennjr@> wrote:

> >

> > Thanks

> > SÃ¸ren,I have done the same thing as you suggested (in

> SufParamStudy.any). However, this means that I’ve to modify some of

> the files in the repository, which I was hoping to avoid. I’ve

> posted a file (SurfParamStudy-Venn.any) that shows an example of

what

> I’m trying to do to the group that better illustrates my

> predicament.For question 1a, can you give me an example. I’m not

sure

> how I’ll be able to use t and Data with design variables.For

question

> 1b, what I meant was this. Instead of me giving the exact data set,

I

> could specify a range [0,10] and ask for say 20 samples. It would

be

> nice if Anybody can pull out these 20 samples from an internally

> generated uniform distribution.Thanks again for the speedy

> response,To: anyscript@: support@: Mon, 19 Feb 2007 10:57:55

> +0000Subject: [anyscript] Re: Parameter Study

> >

> >

> >

> >

> >

> >

> >

> >

> >

> >

> >

> >

> >

> >

> >

> >

> >

> >

> > Hi Venn

> >

> > Thanks for the your suggestions and kind words.

> >

> > It is possible to use the dimensions of a paramsurf as design

> > variable, i have made very simple example illustrating this i

will

> > upload to the file section as “SurfParamStudy.any”, shortly. It

> > has one design variable which change the radius of a cylinder on

> > which a line is wrapping. There is one thing however, the surface

> do

> > not visually change size in the modelview, but if you look at the

> > muscle you can see, it change its size.

> >

> > About your question 1a:

> > It is possible to do a parameter study where the grid is unevenly

> > distributed. This can be done by using a piecewise linear

> > interpoaltion function and use this as a “translation table”. So

> you

> > let your design variable go from for example 0 to 10 and use

> > nstep=10, then you create the interpolation function with t=

> > {0,1,2…9} and Data={Selected values…!}.

> >

> > Question 1b, i am not sure i understand what you mean by uniform

> > distribution in this relation.

> >

> > Question 2: we will consider this for the next release.

> >

> > Qestion 3: This is not possible today because the FileName

property

> > of the Outputfile is a constant, which can not be changed after

> > loadtime, we will also consider to open up for this is the next

> > releases.

> >

> > Again, thanks for your suggestions!

> >

> > Best regards

> > SÃ¸ren

> >

> > — In anyscript@yahoogroups.com, “Vengateswaran J. Ravichandran”

> > <vennjr@> wrote:

> > >

> > > Hello,

> > >

> > > First of all, I’m glad you included Parameter Study in AnyBody

> 2.0.

> > > Because it seems that I cannot change the parameters otherwise,

> > without

> > > creating a new model by writing a file with all the parameters.

> > However,

> > > it seems that I cannot vary parameters that are calculated

rather

> > than

> > > assigned. For example, I’m not able to set the radius of

wrapping

> > > surfaces as a AnyDesVar.

> > > I was trying to set

> > >

> >

>

ShoulderArm.Mus.Pectoralis_minor2_cyl.Cylinder.Cyl.node1.CylSurf.Radiu

> > s,

> > > among others. But I get an error. Is there an alternate way to

do

> > this?

> > > I really appreciate your input.

> > >

> > >

> > >

> > > Here are a few of my thoughts on what more could be done to

> improve

> > > Parameter Study in the next version:

> > > 1a. The rectangular grid function is not very helpful when

> > simulating a

> > > lot of parameters (204, in my case). Perhaps it would help to

> > explain

> > > what I’m doing. Clearly, I do not want to do an exhaustive

> search,

> > since

> > > it will take eons to complete. Perhaps I could specify

specific

> > values

> > > instead, say as a vector?

> > > 1b. Even better would be when I AnyBody can pick a uniform

> sampling

> > of

> > > the space specified. Naturally, this would be an option, rather

> > than the

> > > default. (I’m using MATLAB as a workaround to do just this).

> > >

> > > 2. In what I’m doing, there is also no design measure to

maximize

> or

> > > minimize. So, as of now, I’ve created a dummy DesMeasure that

is

> > set to

> > > zero, since it appears mandatory to have a DesMeasure. I don’t

> > know if

> > > DesMeasure needs to be mandatory. Not an important issue, but

> > thought

> > > I’d mention.

> > >

> > > 3. I think it would be helpful if there is a way to save the

> > results of

> > > ParamStudy into a different file after each run. Let me try to

> > explain

> > > with an example.

> > > Let us say ParamStudy runs KinematicAnalysis that outputs a

> > particular

> > > variable to an OutFile. I don’t want to overwrite OutFile each

> time,

> > > instead it would be great if a new OutFile, say with a suffix

> > indicating

> > > the ParamStudy run number, can be created.

> > >

> > > My thanks to all the folks at the support group. My particular

> > thanks to

> > > SÃ¸ren for all his help.

> > > Your fast turn around time for queries still amazes me. Thank

you

> > for

> > > your patience while I still try to putz around.

> > >

> > > -Venn

> > >

> > >

> > >

> > > [Non-text portions of this message have been removed]

> > >

> >

> >

> >

> > __________________________________________________________

> > Get the most out of tax shelters and other breaks.

> >

>

http://articles.moneycentral.msn.com/Taxes/TaxShelters/TaxShelters.asp

> x?icid=WLtextFebtagline

> >

> > [Non-text portions of this message have been removed]

> >

>

>

>

>

>

>

>

>

>

>

>

>

>

>

>

>

> __________________________________________________________

> Invite your mail contacts to join your friends list with Windows

Live Spaces. It’s easy!

> http://spaces.live.com/spacesapi.aspx?

wx_action=create&wx_url=/friends.aspx&mkt=en-us

>

> [Non-text portions of this message have been removed]

>

Discover the new Windows Vista

http://search.msn.com/results.aspx?q=windows+vista&mkt=en-US&form=QBRE

[Non-text portions of this message have been removed]