mm-214 === Subject: after Koonin's bookI'm reading and enjoying Koonin's book, Computational Physics,and am wondering what I ought to read after that if I want togo further in that direction. I tried asking ts on sci.physicsbut for some reason (maybe imprecise formulation of goals, exceptas implicitly defined by choosing Koonin's book in the first place)I didn't get any replies.Ignorantly,Allan Adlerara@zurich.ai.mit.eduelligence Lab. My actions and === I'm reading and enjoying Koonin's book, Computational Physics,> and am wondering what I ought to read after that if I want to> go further in that direction. I tried asking ts on sci.physics> but for some reason (maybe imprecise formulation of goals, except> as implicitly defined by choosing Koonin's book in the first place)> I didn't get any replies. Ignorantly,> Allan Adler> ara@zurich.ai.mit.eduIt depends on whether you are more interested in the Ôcomputational' or the'physics' aspects. Landau and Paez have a nice book emphasizing the use ofcomputers in computational physics. At NIST there are a number of projectsinvolving computational physics wch are freely shared with the public (theirwork in micromagnetics comes to mind). Perhaps one of the project leaders couldoffer some reading suggestions.--There are two tngs you must never attempt to prove: the unprovable -- and theobvious.--Democracy: The triumph of popularity over === Koonin's bookA rather complete list:http://sip.clarku.edu/books/a.. J. M. Tjssen, Computational Physics, Cambridge University Press(1999). Download programs.Was used by a course at Illinois/Urbana and is used at Columbia. I'm reading and enjoying Koonin's book, Computational Physics,> and am wondering what I ought to read after that if I want to> go further in that direction. I tried asking ts on sci.physics> but for some reason (maybe imprecise formulation of goals, except> as implicitly defined by choosing Koonin's book in the first place)> I didn't get any replies. Ignorantly,> Allan Adler> ara@zurich.ai.mit.edu It depends on whether you are more interested in the Ôcomputational' orthe> Ôphysics' aspects. Landau and Paez have a nice book emphasizing the use of> computers in computational physics. At NIST there are a number of projects> involving computational physics wch are freely shared with the public(their> work in micromagnetics comes to mind). Perhaps one of the project leaderscould> offer some reading suggestions. --> There are two tngs you must never attempt to prove: the unprovable -- and the> obvious.> --> Democracy: The triumph of popularity === enveloping a ßat surface on acurved surfaceI' m looking for a simple algorithm (Fortran o Matlab) to envelope asurface made by few points on a curved surface. Ts should representa metal sheet pressed on a generic surface (Area and edge lenght Applications)The finite-difference time-domain (FDTD) method is one numerical techniquethat has been extensively used in the EM community (academic and industry)to solve and investigate a wide range of EM problems (EMC, EMI, RCS,antennas, circuits, bio-EM, .)Authors are invited to submit their contributions and their experiences inusing and enhancing the FDTD method in the:FDTD Method and ApplicationsSessioninThe 20th Annual Review of Progress in Applied Computational Electromagneticsplease check the following links:http://aces.ee.olemiss.edu/conf/ === Adaptive quadrature integration over trianglesI am looking for an adaptive scheme for integration over triangles for4-point, 6-point and gher quadratures. At the moment the points usedin the 4-point integration and the 6-point integration are completelydifferent. So, if I have to go from a 1-point to 4-point and then to a6-point integration (depending on the tolerance) I end up calculating10 points.Is there a scheme where I can REUSE the previously calculated points(say, 1-point and 4-point integration) for gher quadrature === examples of bad data analysisWhy not contact the editors of some journals to see if they can rememberpublisng and wisng they hadn't?Allan Adlerara@zurich.ai.mit.eduelligence Lab. My === statistic in experimental data evaluationI have the problem that my experimental data, wch was aceved bymechanical stability measurements, shows a gaussian distribution but Iam not quite sure, how to say that effects are really significant.After changing process parameters in the experiment I could really seean effect, mostly the average value differs from the old value. Buthow could I say that ts is really an effect ? That ts issignificant ? Is it just, if the average value of the new experimentis not inside the error bars of the === for BEM all!I have been reading quite a bit about boundary element analysis recently, and I am trying to figure out if there is any consensuswch properties the mesh of the boundary surface should have.Of course the mesng should be as fast as possible and it shouldbe possible to refine the mesh (again as fast as possible).But from all I read it seems as if e.g. the smoothness or similarquality measures of the mesh would only have a relatively minor inßuence on the results. I find ts hard to believe... :-)So are there any quality measures that you would demand of a meshin order to be appropriate for a gh === Seeking Definiton of 3D FFTFolks,How does one compute the FFT of a 3D array? Bascially,knowing how to compute the FFT of a 1D array, how do Igo about computing the FFT of a 3D === does one compute the FFT of a 3D array? Bascially,> knowing how to compute the FFT of a 1D array, how do I> go about computing the FFT of a 3D array?I'm not sure about a 3-D array, but for a 2-D array you simply compute the 1-D FFT of each row (or column), store the results, then compute the 1-D FFT of each column (or row) of ts intermediate array. The result is a 2-D FFT of your array. === FFTOriginator: jeyadev@kaveri>> Folks,How does one compute the FFT of a 3D array? Bascially,>> knowing how to compute the FFT of a 1D array, how do I>> go about computing the FFT of a 3D array?I'm not sure about a 3-D array, but for a 2-D array you simply compute >the 1-D FFT of each row (or column), store the results, then compute the >1-D FFT of each column (or row) of ts intermediate array. The result >is a 2-D FFT of your array. superposition.You give a way of going from a vector to a plane, thanking superposition.Suppose you do that to *each* plane of the 3-d array. Then, can you thank superposition, again?-- Surendar Jeyadev jeyadev@wrc.xerox.bounceback.com Remove === === of 3D FFT>Subject: Re: Seeking Definiton of 3D FFT> Folks,How does one compute the FFT of a 3D array? Bascially,>> knowing how to compute the FFT of a 1D array, how do I>> go about computing the FFT of a 3D array?I'm not sure about a 3-D array, but for a 2-D array you simply compute >the 1-D FFT of each row (or column), store the results, then compute the >1-D FFT of each column (or row) of ts intermediate array. The result >is a 2-D FFT of your array. superposition.That the 2-d Fourier transform can be written at the product of two1-d Fourier transforms is usually called separability. The 3-d Fouriertransform will separate into 3 1-d transforms that can be applied tothe rows, columns and layers (or whatever you call your trd dimension).Keeping track of the shortcuts due to the symmetries from real data canbe a bit more === data analysis> For instructional purposes I am looking for true examples of bad data> analysis in the published literature. A linear regression wch was> not robust and eventually misleading would be such an example. They> can be in any field of science and may involve either real data or> computer simulations, but should be transparent, instructive, and> verifiable. Major storical errors are ideal.If you happen to know of any illustrative example that mislead many> researchers, please let me know.Many ,> norb1@yahoo.comThe easiest mistake is in cosmology, when calculating the functionbetween a tng's distance from us and it's speed. Normally it's takenthat V = D*H where H is a constant (I tnk it's called the hubbleconstant.) is exact, but ts violates relativity in that you can getV = c.Ts is why: If observer in galaxy 1 sees galaxy 2 moving away at 2/3c, and obserber in galaxy 2 sees galaxy 3 moving away at 2/3 c, thenrelativity tells us that observer 1 in galaxy 1 should see galaxy 3moving away at (2/3+2/3)/(1+2/3*2/3) = 12/13 c.However, using the regression that astronomers usually use, galaxy 2would calculate that galaxy 1 is a distance of D=4/3 c/H from galaaxy3. Since galaxy 2 is moving at 2/3 c away from galaxy 1, then ingalaxy 1's reference frame, their distance apart should be D/y =(4/3)(c/H)/sqrt(1-(2/3)^2) = (4/3)(c/H)/sqrt(5/9) = 4/sqrt(5) c/H fromthe Lorentz contraction, but that means their relative velocities fromthe above relation must be (4/sqrt(5))*c/H*H = (4/sqrt(5))*c, wch ismuch different from 12/13 c, meaning that the answer is notconsistent.Now ts is just a single case, but I'm willing to bet that I, andanyone else here can find several contradictions. Particularly, if thedistance is far enough such that D*H>c we get an obvious violation ofrelativity, where a simple calculation through integration by assumingthat the relative expansion velocity between two neighboring points infree (IE no or very little gravitational interaction, even relative towitn galaxies.) space is constant will give us a nonlinear formulabut wch prevents any galaxy from moving at a speed c or greaterrelative to us. Either that or there's a limit to the distance ofD For instructional purposes I am looking for true examples of bad data> analysis in the published literature. A linear regression wch was> not robust and eventually misleading would be such an example. They> can be in any field of science and may involve either real data or> computer simulations, but should be transparent, instructive, and> verifiable. Major storical errors are ideal.> If you happen to know of any illustrative example that mislead many> researchers, please let me know.Some disasters attributable to bad numerical === Re: Looking for examples of bad data analysis> For instructional purposes I am looking for true examples of bad data> analysis in the published literature. A linear regression wch was> not robust and eventually misleading would be such an example. They> can be in any field of science and may involve either real data or> computer simulations, but should be transparent, instructive, and> verifiable. Major storical errors are ideal.Two examples that come to mind are the Challenger and Columbiashuttle accidents. At Edward Tufte's web site (http://www.edwardtufte.com) there is adiscussion of a slide taken from a presentation made by NASA engineersto management, under the heading ET on Columbia Evidence.The key feature, to me, is a bullet point near the bottom of theslide, reading, Flight condition is significantly outside of testdatabase. Ts should have been a warning of all bets are off,but as we know, wishful tnking prevailed instead.In the case of the Challenger accident, there was evidence to suggest that cold weather could affect the O-rings wch sealthe booster rockets. IIRC engineers recommended the launch bepostponed, but management decided to go ahead anyway. There isa discussion of the Challenger accident in Richard Feynman's book,What Do YOU Care What Other People Tnk?, and s personalcomments, as a member of the Rogers commission, can be found on theweb (http://science.ksc.nasa.gov/shuttle/missions/51-l/docs/ rogers-commission/Appendix-F.txt).It is easy to point fingers in ndsight, but there is a lessonfor us all here; namely that making decisions is very, very hard.The only way out that I see is to invest more time in the decisionprocess, and practice a lot.For what it's worth,Robert Dodier--For a successful technology, reality must take precedence over public relations, for nature cannot be fooled. -- Richard === exist a smart method that quickly inverts an hermitian === need to compose a list of all possible three number sets using the>>numbers 1 through 4. can anyone help me compile a list? All help will>>be greatly appriciated(spelling) . > Can you use numbers more than once?If you can, start with:> 1111> 1112> 1113> 1114> 1121> 1122> 4444(ie, increment the last digit as many times as you can, then let it roll > over to the next digit, just like a clock or odometer)If you can only use each number once, simply eliminate everytng from > the above list with duplicate digits. So you'd have (again, smallest to > largest)1234> 1243> 1324> etcUh, those are _four_ number sets, but they do give the basic idea.--JeffNext trick, counting to 1023 on your fingers.-- Ho, ho, ho, hee, hee, heeand a couple of ha, ha, has;That's how we pass the day away,in the merry old land of Oz.-- submissions: post to k12.ed.math or e-mail to k12math@k12groups.orgprivate e-mail to the k12.ed.math moderator: kem-moderator@k12groups.orgnewsgroup website: http://www.tnkspot.net/k12math/newsgroup charter: === Creative Publications... Middle School Math with PizzazzI need to order the math books called Middle School Math WithPizzazz. I use them for tutoring my students and they love it. I amunable to find information. Can you please let me know where to findthese books? in advance, Jaime Gall-- submissions: post to k12.ed.math or e-mail to k12math@k12groups.orgprivate e-mail to the k12.ed.math moderator: kem-moderator@k12groups.orgnewsgroup website: http://www.tnkspot.net/k12math/newsgroup charter: === Creative Publications... Middle School Math with Pizzazz> I need to order the math books called Middle School Math With> Pizzazz. I use them for tutoring my students and they love it. I am> unable to find information. Can you please let me know where to find> these books? in advance, Jaime GallI did a quick Google search, first with middle school math with pizzazzthen with middle school math with pizzazz creative publicationsSome of the websites you'll want to check are the authors' web site: http://www.marcymathworks.com/ the publisher's web site: http://www.wrightgroup.com/You can order direct from the publisher: Middle School Math With Pizzazz! All 5 Binders Author: Steve Marcy and Janis Marcy Series: Pizzazz! ISBN: the embarassment of askingquestions that can be answered in a minute or two with a quick search.-- Kevin Karplus karplus@soe.ucsc.edu http://www.soe.ucsc.edu/~karpluslife member (LAB, Adventure Cycling, American Youth Hostels)Effective Cycling Instructor #218-ck (lapsed)Professor of Biomolecular Engineering, University of California, Santa CruzUndergraduate and Graduate Director, BioinformaticsAffiliations for identification only.-- submissions: post to k12.ed.math or e-mail to k12math@k12groups.orgprivate e-mail to the k12.ed.math moderator: kem-moderator@k12groups.orgnewsgroup website: http://www.tnkspot.net/k12math/newsgroup charter: === Slovenian Mathematics,I just posted ts message on a Slovenian Culture newsgroup, and Iwanted to include a copy here in case anybody could provide me withany information or thoughts. Even information or thoughts on where Ican go next for information about Slovenian Mathematical Curriculumwould be most appreciated. ~JosephMy name is Joseph Sustar, and I am a gh school Mathematics teacherin New York City, USA. I am also currently pursuing my Masters degreein Secondary Mathematics at the City College of New York. As part ofmy studies, I am doing a comparative study of how Mathematics istaught in various countries.I am interested in anybody's insights as former or current students,teachers, citizens of Slovenia, or from people who know the culturewell.My grandparents are originally from Slovenia, and given the recentpolitical sfts in Slovenia, I am particularly interested in howMathematics is taught there.Any information that anybody can provide would be most appreciated. Also, if you would be able to forward ts message to any Mathematicsteachers (or any teachers) who would be interested in responding, Iwould be very grateful.I am looking for answers to the following questions: 1) What is the basic outline of the Mathematics curriculum fromgrades K-12 (from the start of schooling up through gh school)?2) When do you (they) teach what Mathematics subject? For instance,when is Algebra taught? When is Geometry taught? When is Calculustaught?3) How is Mathematics taught in Slovenia? 4) Do all students follow the same academic path? Do all students gointo academic studies? Or are there various tracks for students? Howdo the various tracks affect how Mathematics is taught?5) When Slovenia regained their independence from Yugoslavia at theend of the Cold War, how was the educational system, and Mathematicsin particular, affected? Are there remnants of the old system? orwas there an effort to change tngs? very much for your time and for any answers that you areable to provide.You can either respond here, or email me k12.ed.math or e-mail to k12math@k12groups.orgprivate e-mail to the k12.ed.math moderator: kem-moderator@k12groups.orgnewsgroup website: http://www.tnkspot.net/k12math/newsgroup charter: === Slovenian MathematicsI am Hungarian, that country belonged the same cultural cradle as Slovenia, and the curriculum was prescribed under the same Ratio Educationis introduced first in 1756 and renewed occasionallyHere are the answers, how was the education till the end of the communist era (interestingly communist did not changed the former curriculum, math and science were intact from the ideology)<<1) What is the basic outline of the Mathematics curriculum fromgrades K-12 (from the start of schooling up through gh school)?2) When do you (they) teach what Mathematics subject? For instance,when is Algebra taught? When is Geometry taught? When is Calculustaught?3) How is Mathematics taught in Slovenia? >>No math curriculum for Kindergarten, most cldren did not attended Kindergarten at all.Grades 1-2 : counting, adding subtracting 1-20Grade 3 : numbers 1-100, multiplicationGrade 4 : division, rations, numbers to infinityGrades 5-6 : repetition of the previous years, intro to geometry.Grade 7 : pre-algebraGrade 8 : AlgebraGrade 9 : repetition of the previous yearsGrade 10 : Introduction to trigonometry and analytic geometryGrade 11 : Pre-calculusGrade 12 : Calculus, projective geometry.any difference in the given school.<4) Do all students follow the same academic path? Do all students gointo academic studies? Or are there various tracks for students? Howdo the various tracks affect how Mathematics is taught? >>No.About half of the student after the 8-th grade went to 2 years trade schools, wch did not provided new topics in Math.About 25% went to technical schools wch were 4 year schools with emphasis on some topic, ts schools did not covered the pre-calculus and calculus.For the rest 25%, the gymnasium, the curriculum was the same, it was the college preparatory curriculum.<<5) When Slovenia regained their independence from Yugoslavia at theend of the Cold War, how was the educational system, and Mathematicsin particular, affected? Are there remnants of the old system? orwas there an effort to change tngs? >>Again I don't know Slovenia just Hungary. The above described 200+ years old curriculum was abandoned, the schools decide themselves what to teach, a lot of electives instead of the obligatory requirement. The process started in the eighties. In 1992 Hungary was still in the first 5 in the international test, by 1998 it fall down to the 15-16-th place. About 10% of the schools keeps the original curriculum, in the rest the problem is the lack of discipline, wch makes impossible the teacng. (Ts later part are know only from my frienlaszlo-- submissions: post to k12.ed.math or e-mail to k12math@k12groups.orgprivate e-mail to the k12.ed.math moderator: kem-moderator@k12groups.orgnewsgroup website: http://www.tnkspot.net/k12math/newsgroup charter: === Sylvan Learning center to catch up in math/reading?Find a Kumon and have them do that for the Math. At the end of 2nd gradeour son was the worst math student ( new math wch stinks) by theend of 3rd he was the best. I just had s IQ tested 1/2 through 4th andhe is testing in the genius level for math, had s IQ tested inkindergarten and it was 100 in math. The same psychologist did both testsand they have no idea about m doing kumon. Ts was the best tng weever did. $90 a month 10-15 minutes a day. s self esteem is 1000x better.I doubt Sylvan or a tutor can do ts. We didn't do the Kumon English sincehe has always done well in it. I expect them to be as good in Englishthough.Good luck,Paul> Our fourth grade son was recently assessed at a Sylvan Learning> Center. We had m assessed because he is falling bend at school.> The special education services he has received have allowed m to> fall drastically bend in the area of math. The total math score was> a grade level of 3.2, and our son is currently in s 6th month of> fourth grade. We also suspected a possible comprehension problem with> reading. The reading assessment showed only 70% comprehension, all> other reading scores were average. We are considering spending a> great deal of time and money to hopefully have our son catch up to> grade level by the time he begins fifth grade in September. We would> like to hear about good/bad experiences regarding Sylvan from people> in similar situations? in advance.>-- submissions: post to k12.ed.math or e-mail to k12math@k12groups.orgprivate e-mail to the k12.ed.math moderator: kem-moderator@k12groups.orgnewsgroup website: http://www.tnkspot.net/k12math/newsgroup charter: === Sylvan Learning center to catch up in math/reading?> Find a Kumon and have them do that for the Math.I'll second the Kuman learning center. Much cheaper and better. :o)--Sue (mom to three girls)I'm Just a Raggedy Ann in a Barbie Doll World...-- submissions: post to k12.ed.math or e-mail to k12math@k12groups.orgprivate e-mail to the k12.ed.math moderator: kem-moderator@k12groups.orgnewsgroup website: http://www.tnkspot.net/k12math/newsgroup charter: === Sylvan Learning center to catch up in math/reading?> Our fourth grade son was recently assessed at a Sylvan Learning> Center. We had m assessed because he is falling bend at school.> The special education services he has received have allowed m to> fall drastically bend in the area of math. The total math score was> a grade level of 3.2, and our son is currently in s 6th month of> fourth grade. We also suspected a possible comprehension problem with> reading. The reading assessment showed only 70% comprehension, all> other reading scores were average. We are considering spending a> great deal of time and money to hopefully have our son catch up to> grade level by the time he begins fifth grade in September. We would> like to hear about good/bad experiences regarding Sylvan from people> in similar situations? in advance.You should call a new IEP meeting to disucss ts.Take s tests and graphthem for impact. Then insist that the school provide tutoring 1:1 or havethem pay for Sylvan.-- submissions: post to k12.ed.math or e-mail to k12math@k12groups.orgprivate e-mail to the k12.ed.math moderator: kem-moderator@k12groups.orgnewsgroup website: http://www.tnkspot.net/k12math/newsgroup charter: === combinationsthe answers are 45 for 2 combinations and 120 for 3 combinations.use the formula C(n,r)=n!/(n-r)!r!where n is your total number of objects (10 in ts case) and r is thenumber that you have in your combination (1,2,3 in ts case) so justplug the numbers in-- submissions: post to k12.ed.math or e-mail to k12math@k12groups.orgprivate e-mail to the k12.ed.math moderator: kem-moderator@k12groups.orgnewsgroup website: http://www.tnkspot.net/k12math/newsgroup charter: === possible answeri'm not sure ts is entirely correct, but i'll go thru all of thesteps.You can retrieve ts answer by using the equation C(n,r)=n!/(n-r)!r!where n is the number of total numbers (49), and r is the amount ofnumbers in your combination (5).C(n,r)=49!/(49-5)!5!C(n,r)=49!/44!(120)Getting the exact answer would take a lot of calculating... but again,i'm not exactly sure that ts is correct. can anyone verify my work?-- submissions: post to k12.ed.math or e-mail to k12math@k12groups.orgprivate e-mail to the k12.ed.math moderator: kem-moderator@k12groups.orgnewsgroup website: http://www.tnkspot.net/k12math/newsgroup charter: === possible answer> i'm not sure ts is entirely correct, but i'll go thru all of the> steps.> You can retrieve ts answer by using the equation C(n,r)=n!/(n-r)!r!> where n is the number of total numbers (49), and r is the amount of> numbers in your combination (5).> C(n,r)=49!/(49-5)!5!> C(n,r)=49!/44!(120)Getting the exact answer would take a lot of calculating... but again,> i'm not exactly sure that ts is correct. can anyone verify my work?Slow down. 49! = 49 * 48 * 47 * 46 * 45 * 44 * 43 * 42 * ... 44! = 44 * 43 * 42 * ...Does that help?