## Something to discuss about CASes

Maple

I'd like to pay attention to the recent article "The Misfortunes of a Trio of Mathematicians Using Computer Algebra Systems. Can We Trust in Them?"

In particular, the authors consider the integral

int(abs(exp(2*Pi*Ix)+exp(2*Pi*I*y)),[x=0..1,y=0..1]),

stating "Both Mathematica and Maple return zero as the answer to this calculation. Yet this cannot be correct, because the integrand is clearly positive and nonzero in the indicated region". Unfortunately, they give only the Mathematica command to this end.

Of course, the integral under consideration is complicated so the the simple-minded trials

int(evalc(abs(exp((2*Pi*I)*x)+exp((2*Pi*I)*y))), [x = 0 .. 1, y = 0 .. 1]);

and

VectorCalculus:-int(evalc(abs(exp((2*Pi*I)*x)+exp((2*Pi*I)*y))), [x,y]=Rectangle( 0 .. 1, 0 .. 1));

fail. However,this can be found with Maple (I think with Mathematica too.) in such a way.

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## Visualization of meme propagation on the internet

by:

Hi, we recently put together a web video on how memes spread on the internet using several visualizations generated from Maple 18:

http://youtu.be/vEhAkEPwESI

Found the new ability to specify a background image for plots to be very helpful.

## MapleSim 7 is now available

We have just released a new version of MapleSim.

MapleSim 7 makes it substantially easier to explore and validate designs, create and manage libraries of custom components, and use your MapleSim models with other tools. It includes:

• Easy model investigation. A new Results Manager gives you greater flexibility when it comes to investigating your simulation results, including the ability to compare simulation runs on the same axes, instantly plot both probed and unprobed variables, and easily create custom plots.
• Convenient library creation. With MapleSim 7, it is significantly easier to create, manage, and share libraries of custom components.
• Improved Modelica support. MapleSim 7 expands the support of the Modelica language so that more Modelica definitions can be used directly inside MapleSim.

We have also updated and expanded the MapleSim 7 family of add-on products:

• The new MapleSim Battery Library, which is available as a separate add-on, allows you to incorporate physics-based predictive models of battery cells into your system models so you can take battery behavior into account early in the design process.
• The MapleSim Connector for FMI, which allows engineers to share very efficient, high-fidelity models created in MapleSim with other modeling tools, has been expanded to support more export formats for co-simulation and model exchange.

eithne

## Computer Algebra for Theoretical Physics

by:

Last week the Physics package was presented in a talk at the Perimeter Institute for Theoretical Physics and in a combined Applied Mathematics and Physics Seminar at the University of Waterloo. The presentation at the Perimeter Institute got recorded. It was a nice opportunity to surprise people with the recent advances in the package. It follows the presentation with sections closed, and at the end there is a link to a pdf with the sections open and to the related worksheet, used to run the computations in real time during the presentation.

COMPUTER ALGEBRA FOR THEORETICAL PHYSICS

 Generally speaking, physicists still experience that computing with paper and pencil is in most cases simpler than computing on a Computer Algebra worksheet. On the other hand, recent developments in the Maple system implemented most of the mathematical objects and mathematics used in theoretical physics computations, and dramatically approximated the notation used in the computer to the one used in paper and pencil, diminishing the learning gap and computer-syntax distraction to a strict minimum. In connection, in this talk the Physics project at Maplesoft is presented and the resulting Physics package illustrated tackling problems in classical and quantum mechanics, general relativity and field theory. In addition to the 10 a.m lecture, there will be a hands-on workshop at 1pm in the Alice Room.

 ... Why computers? We can concentrate more on the ideas instead of on the algebraic manipulations   We can extend results with ease   We can explore the mathematics surrounding a problem   We can share results in a reproducible way

Representation issues that were preventing the use of computer algebra in Physics

Notation and related mathematical methods that were missing:

coordinate free representations for vectors and vectorial differential operators,

covariant tensors distinguished from contravariant tensors,

functional differentiation, relativity differential operators and sum rule for tensor contracted (repeated) indices

Bras, Kets, projectors and all related to Dirac's notation in Quantum Mechanics

Inert representations of operations, mathematical functions, and related typesetting were missing:

inert versus active representations for mathematical operations

ability to move from inert to active representations of computations and viceversa as necessary

hand-like style for entering computations and texbook-like notation for displaying results

Key elements of the computational domain of theoretical physics were missing:

ability to handle products and derivatives involving commutative, anticommutative and noncommutative variables and functions

ability to perform computations taking into account custom-defined algebra rules of different kinds

(problem related commutator, anticommutator, bracket, etc. rules)

 Vector and tensor notation in mechanics, electrodynamics and relativity
 Dirac's notation in quantum mechanics

 • Computer algebra systems were not originally designed to work with this compact notation, having attached so dense mathematical contents, active and inert representations of operations, not commutative and customizable algebraic computational domain, and the related mathematical methods, all this typically present in computations in theoretical physics.
 • This situation has changed. The notation and related mathematical methods are now implemented.

Tackling examples with the Physics package

Classical Mechanics

Inertia tensor for a triatomic molecule

Problem: Determine the Inertia tensor of a triatomic molecule that has the form of an isosceles triangle with two masses  in the extremes of the base and mass  in the third vertex. The distance between the two masses  is equal to a, and the height of the triangle is equal to h.

 Solution

Quantum mechanics

Quantization of the energy of a particle in a magnetic field

Show that the energy of a particle in a constant magnetic field oriented along the z axis can be written as

where and  are creation and anihilation operators.

 Solution
 The quantum operator components of  satisfy

Unitary Operators in Quantum Mechanics

(with Pascal Szriftgiser, from Laboratoire PhLAM, Université Lille 1, France)

A linear operator U is unitary if , in which case, Unitary operators are used to change the basis inside an Hilbert space, which physically means changing the point of view of the considered problem, but not the underlying physics. Examples: translations, rotations and the parity operator.

 1) Eigenvalues of an unitary operator and exponential of Hermitian operators
 2) Properties of unitary operators
 3) Schrödinger equation and unitary transform
 4) Translation operators

Classical Field Theory

The field equations for a quantum system of identical particles

Problem: derive the field equation describing the ground state of a quantum system of identical particles (bosons), that is, the Gross-Pitaevskii equation (GPE). This equation is particularly useful to describe Bose-Einstein condensates (BEC).

 Solution
 The field equations for the  model
 Maxwell equations departing from the 4-dimensional Action for Electrodynamics

General Relativity

Given the spacetime metric,

a) Compute the trace of

where  is some function of the radial coordinate,  is the Ricci tensor,  is the covariant derivative operator and  is the stress-energy tensor

b) Compute the components of the traceless part of   of item a)

c) Compute an exact solution to the nonlinear system of differential equations conformed by the components of   obtained in b)

Background: paper from February/2013, "Withholding Potentials, Absence of Ghosts and Relationship between Minimal Dilatonic Gravity and f(R) Theories", by P. Fiziev.

 a) The trace of
 b) The components of the traceless part of
 c) An exact solution for the nonlinear system of differential equations conformed by the components of
 The Physics Project "Physics" is a software project at Maplesoft that started in 2006. The idea is to develop a computational symbolic/numeric environment specifically for Physics, targeting educational and research needs in equal footing, and resembling as much as possible the flexible style of computations used with paper and pencil. The main reference for the project is the Landau and Lifshitz Course of Theoretical Physics.   A first version of "Physics" with basic functionality appeared in 2007. Since then the package has been growing every year, including now, among other things, a searcheable database of solutions to Einstein equations and a new dedicated programming language for Physics.   Since August/2013, weekly updates of the Physics package are distributed on the web, including the new developments related to our plan as well as related to people's feedback.

Edgardo S. Cheb-Terrab
Physics, Differential Equations and Mathematical Functions, Maplesoft

## Solutions of Differential Equations with Embedded...

Maple 18

The Embedded Components are containers that currently use industries for modeling complex systems to find viable solutions in real time and thus avoid huge wait times and overload our computer; by this paper should show you how to implement a dynamic worksheet through Embedded Components in Maple; it goes from finding solutions to ordinary differential equations partial; which interact with the researcher using different parameters.
Using graphical programming will find immediate solutions to selected problems in science and engineering criteria of variability and boundary conditions evolving development with buttons on multiple actions.

cimac_2014.pdf

(in spanish)

Solutions_of_Differential_Equations_with_Embedded_Components.mw

Lenin Araujo Castillo

Physics Pure

Computer Science

## October Live Webinars

by: Maple

Maplesoft regularly hosts live webinars on a variety of topics. Below you will find details on some upcoming webinars we think may be of interest to the MaplePrimes community.  For the complete list of upcoming webinars, visit our website.

Maplesoft Solutions for Math Education

This webinar will demonstrate how Maplesoft’s solutions for mathematics education help teachers bring complex problems to life, allow students to focus on concepts rather than the mechanics of solutions, and offer students the necessary practice to master the concepts being taught.

Key takeaways include:

• How to quickly and painlessly place incoming students in the correct math courses

• How you can use hundreds of intuitive Clickable Math tools to demonstrate and explore up to advanced-level problems and algorithms in the classroom

• How to automate your testing and assessment needs, specifically for math courses

• How to bring your STEM courses to life in an online environment

Introduction to Maple T.A. Placement Test Suite 10

This webinar will provide an overview and demonstration of the latest release of the Maple T.A. MAA Placement Test Suite. A result of the ongoing partnership between the Mathematical Association of America (MAA) and Maplesoft, this product gives you the ability to provide the renowned MAA placement tests in an online testing environment. Learn how the Maple T.A. MAA Placement Test Suite can greatly simplify your placement process and explore the latest additions, including a streamlined interface and new tests to determine your students’ readiness for Precalculus and Algebra courses.

There is also a recording available from another live webinar we did earlier this month: Introduction to Maple T.A. 10.

## Photon Exposure

by: Maple 18

This application calculates the number of photons reaching a camera sensor for a given exposure. A blackbody model of the sun is generated. The "Sunny 16" rule for exposure is demonstrated. Calculations are done using units.Photon_Exposure_Array.mw

Photon Exposure

Blackbody Model of the Sun

 Plank Constant Boltzman Constant Light Speed Sun Radius Earth Orbit Sun Color Temperature Transmission Factor

=

 Photopic Relative Response VP vs λ =  =                (ArrayInterpolation for x,y data VPdata returns y' for new x data lambdaP)

Illuminance in Radiometric and Photometric Units:

=

=

Translation from Illuminance to Luminance for Reflected Light;

Object Reflectance

Object Luminance                            =

Illuminance of a Camera Sensor  Eps applied for time texp determines Luminous Exposure Hp;

Ideal Illuminance is determined by the exposure time texp, effective f-number N and to a less extent the angle to the optical axis θ;

 • H       Luminous Exposure
 • Eps     Illuminance to the Camera
 • N                                               Effective F-Number
 • texp             Exposure Time
 • θ        Angle to the Optical Axis

The camera meter determines the exposure time texp to balance the object luminance, reflectance and effective f-number. It does this based on an internal constant k and the camera ISO s.

 • s        ISO Gain (Based on saturation at 3 stops above the average scene luminance)
 • k       Reflected Light Meter Calibration Constant

for Nikon, Canon and Sekonic

 • c        Incident Light Meter Calibration Constant

for Sekonic with flat dome

(Incident Light Meter)

(Reflected Light Meter)

 Solve for H in terms of the Camera Meter Constant k and s

=

Note:  Meters are typically set for a scene reflectance 3 stops below 100% or 12.5%.

=

=

Actual exposure time includes typical lens losses;

 Magnification Lens Transmittance Lens Flare Vignetting

Total Lens Efficiency

=

Replacing Eps with q*Eps we get the "Sunny 16" relation between exposure time and ISO;

=

=

 • The Number of Photons NP Reaching the Sensor Area A;
 • Circle of confusion for 24x36mm "Full Frame" for 1 arcminute view at twice the diagonal:

 • Sensor Bandwidth                                          Photopic Response VP
 • Exposure Time for Zone 5: Rscene=12.5% , Saturation in Zone 8 Rscene=100%
 • Camera ISO differs from Saturation ISO. Typical Saturation ISO is 2300 when the camera is set to 3200. See DxoMark.

The average number of photons for exposure time based on Reflectance of the scene  relative to the metered value:

Zone 5;

=

Zone 8;

=

Approximate Formula

:

=

Average Visible Photon Energy

=

=

## Create DNG Matrices Using Optimization

by: Maple 18

Obsolete

See my Camera Profiler application instead.

This application creates DNG matrices by optimizing Delta E from a raw photo of x-rites color checker. The color temperature for the photograph is also estimated.  Inputs are raw data from RawDigger and generic camera color response from DXO Mark.

 Initialization

XYZoptical to RGB to XYZdata

Sr,g,b is the relative spectral transmittance of the filter array not selectivity for XY or Z of a given color.

Pulling Sr,g,b out of the integral assumes they are scalars. For example Sr attenuates X, Y and Z by the same amount.

Raw Balance is not White Point Adaptation.

The transmission loss of Red and Blue pixels relative to green is compensated by D=inverse(S). The relation to incident chromaticity, xy is unchanged as S.D=1.

(See Bruce Lindbloom; "Spectrum to XYZ" and "RGB/XYZ Matrices" also, Marcel Patek; "Transformation of RGB Primaries")

 • XYZ to RGB

 • RGB to XYZ (The extra step of adaptation to D50 is included below)

 Functions

 Input Data

 Solve for Camera to XYZ D50 and T

## Special bounded partial sums

For all real a, the partial sums sn= sum((-1)^k (k^(1/k) -a), k=1..n) are bounded so that their limit points form an interval [-1.+  the MRB constant +a, MRB constant] of length 1-a, where the MRB constant is limit(,N=infinity).

For all complex z, the upper limit point of  sn= sum((-1)^k (k^(1/k) -z), k=1..n) is the  the MRB constant.

We see that maple knows the basics of this because when we enter sum((-1)^k*(k^(1/k)-z), k = 1 .. n)

maple gives

marvinrayburns.com

## Banque de questions MapleTA en français – plus...

by:

Aujourd’hui, je suis ravis d’annoncer la disponibilité d’une large banque de questions françaises supportant les enseignements du secondaire et de l’enseignement supérieur. Ce contenu didactique est disponible via le MapleTA Cloud, et également grâce au lien de téléchargement ci-dessous.

Lien de téléchargement de la banque de questions françaises

Ces questions sont librement et gratuitement accessibles, et vous pouvez les utiliser directement sur vos propres évaluations et exercices dans MapleTA, ou les éditer et modifier pour les adapter à vos besoins.

Le contenu de cette banque de questions françaises traite de sujets pour les classes et enseignements pré-bac, post-bac pour en majorité les matières scientifiques.

Les matières traitées par niveaux et domaines sont:

Lycées :

• Electricité
• Équations Différentielles
• Gravitation universelle
• Langues
• Maths I
• Maths II
• Physique
• Chimie
• Mécanique

Enseignement supérieur (Post-Bac) :

• Astrobiologie
• Introduction au Calcul pour la Biologie
• Chimie
• Déplacement d'onde
• Electricité & Magnétisme
• Maths pour l’économie
• Maths Post-Bac
• Mécanique Angulaire
• Mécanique des Fluides
• Mécanique linéaire
• Physique Post-Bac
• Electrocinétique
• Matériau
• Mécanique des Fluides
• Thermodynamique

Jonny Zivku
Maplesoft Product Manager, Maple T.A.

## Maple T.A. course materials – Introductory Calculus ...

by:

Several Maple T.A. users have developed comprehensive sets of question content and assignments to support full courses in Maple T.A. These questions are available through the Maple T.A. Cloud, and we have decided to also post the associated course modules on Maple Primes as an alternative way of accessing this content.

Below you will find a link to the Introductory Calculus Maple T.A.. course module developed by Keele University.

This testing content is freely distributed, and can be used in your own Maple T.A. tests either as-is, or with edits.

These questions are designed to accompany the first semester of an introductory honours calculus course. The course is intended primarily for students who need or expect to pursue further studies in mathematics, physics, chemistry, engineering and computer science. With over 250 question, topics include: basic material about functions, polynomials, logs and exponentials, the concept of the derivative, and lots of practise exercises for finding derivatives and integrals, and material about series.

Jonny Zivku
Maplesoft Product Manager, Maple T.A.

## Maple T.A. course materials – Introductory Calculus...

by:

Several Maple T.A. users have developed comprehensive sets of question content and assignments to support full courses in Maple T.A. These questions are available through the Maple T.A. Cloud, and we have decided to also post the associated course modules on Maple Primes as an alternative way of accessing this content.

Below you will find a link to the Introductory Calculus for Biological Sciences Maple T.A.. course module developed by the University of Guelph.

This testing content is freely distributed, and can be used in your own Maple T.A. tests either as-is, or with edits.

The Introductory Calculus for Biological Sciences course module is designed to cover a single-semester introductory calculus course for biological sciences students at the first-year university level. The questions are designed to span the topics listed below, allowing for practice, homework or testing throughout the semester.

Topics include:

• Introduction to Functions
• Composite and Inverse Functions
• Trigonometric Functions
• Logarithms and Exponents
• Sequences and Finite Series
• Limits and Continuity
• Derivatives
• Curve Sketching
• Differentials
• Linear Approximation
• Taylor Polynomials
• Difference Equations
• Log-Log Graphs
• Anti-Differentiation
• Definite Integrals

Jonny Zivku
Maplesoft Product Manager, Maple T.A.

## Maple T.A. course materials – Introductory Mathema...

by:

Several Maple T.A. users have developed comprehensive sets of question content and assignments to support full courses in Maple T.A. These questions are available through the Maple T.A. Cloud, and we have decided to also post the associated course modules on Maple Primes as an alternative way of accessing this content.

Below you will find a link to the Introductory Mathematical Economics Maple T.A.. course module developed by the University of Guelph.

This testing content is freely distributed, and can be used in your own Maple T.A. tests either as-is, or with edits.

The Introductory Mathematical Economics course module is designed to cover a single-semester course in mathematical economics for economics and commerce students at the second-year university level. The questions are designed to span the topics listed below, allowing for practice, homework or testing throughout the semester.

Topics include:

• Rules of Differentiation
• First Order Differential Equations
• Higher Order Derivatives
• Optimization in One Variable
• Second Order Conditions for Optimization
• Systems of Linear Equations
• Optimization with Direct Restrictions on Variables
• Over Determined and Under Determined Systems
• Matrix Representation of Systems
• Gauss Jordan
• Matrix Operations
• Types of Matrices
• Determinants and Inverses
• Partial Differentiation
• Second Order Partial Derivatives
• Multivariate Optimization
• Second Order Conditions for Multivariate Optimization
• Multivariate Optimization with Direct Restrictions of Variables
• Constrained Optimization and the Lagrangean Method
• Second Order Conditions for Constrained Optimization

Jonny Zivku
Maplesoft Product Manager, Maple T.A.

## Maple T.A. course materials – Introductory Electricity...

by:

Several Maple T.A. users have developed comprehensive sets of question content and assignments to support full courses in Maple T.A. These questions are available through the Maple T.A. Cloud, and we have decided to also post the associated course modules on Maple Primes as an alternative way of accessing this content.

Below you will find a link to the Introductory Electricity & Magnetism Maple T.A.. course module developed by the University of Guelph.

This testing content is freely distributed, and can be used in your own Maple T.A. tests either as-is, or with edits.

The Introductory Electricity & Magnetism course module is designed to cover a single-semester course in electricity and magnetism for physical sciences students at the first-year university level. The questions are designed to span the topics listed below, allowing for practice, homework or testing throughout the semester. Using the Maple engine that is part of Maple TA, a custom grading engine has been developed to provide even more flexible grading of scalar and vector responses. This partial grading engine can be configured to, among other things, assign part marks for missing units, transposed or missing vector components or missing algebraic terms.

Topics include:

• Cross Products
• Coulomb’s Law
• Electric Fields
• Point Charge Distributions
• Continuous Charge Distributions (Integration)
• Electric Potential
• Electric Potential Energy
• Electromotive Force
• Resistance
• Capacitance
• Kirchhoff’s Laws
• Magnetic Fields
• Magnetic Fields Due to Current Carrying Wires
• Forces on Wires in Magnetic Fields
• Forces on Charges in Electric and/or Magnetic Fields
• EM Waves
• Two Source Interference
• Double Slit Interference
• Single Slit Diffraction
• Diffraction Gratings

Jonny Zivku
Maplesoft Product Manager, Maple T.A.

## Maple T.A. course materials – Statistics (University...

by:

Several Maple T.A. users have developed comprehensive sets of question content and assignments to support full courses in Maple T.A. These questions are available through the Maple T.A. Cloud, and we have decided to also post the associated course modules on Maple Primes as an alternative way of accessing this content.

Below you will find a link to the Statistics Maple T.A.. course module developed by the University of Guelph.

This testing content is freely distributed, and can be used in your own Maple T.A. tests either as-is, or with edits.

The Statistics course module is designed to cover a single-semester course in statistics for science students at the second-year university level. The questions are designed to span the topics listed below, allowing for practice, homework or testing throughout the semester. The questions are mainly of an applied nature and do not delve very deeply into the underlying mathematical theory.

Topics:

• Introduction to Statistics
• Descriptive Statistics
• Basic Probability
• Discrete Random Variables
• Continuous Random Variables
• Sampling Distributions
• Inference for Means
• Inference for Proportions
• Inference for Variances
• Chi-square Tests for Count Data
• One-Way ANOVA
• Simple Linear Regression and Correlation

Jonny Zivku
Maplesoft Product Manager, Maple T.A.

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