## How to tell Maple that |a,b,c> is an eigenvector o...

Hi everyone,

I am exploring the physics package a bit. However, in the documentation I didn't find anything about how to setup operator-ket relations like:

A | l,m,n > = f(l,m,n) | g(l,m,n), h(l,m,n), z(l,m,n) >

The Creation and Annihilation operators were the only predefined ones I found.

Cheers

NOh

## help. How do you enter limits, is there a lim as x...

My instructor gave me the problem lim as x goes to 0 of ((2 + x)^3 +8)/x I can't figure out how to get the lim as x goes to, to show up.  There is no button for it in the expressions pallette like there is for things like the piecewise function. My instructor won't help me.  Is there a basic guide I can buy or something.  This software isn't very intuitive.

## How to get maple 18 working?...

The installation / activation went without trouble. The problem occurs when I want to start Maple. The splash screen shows up with a blue loading bar and that's it. It just keeps loading, sometimes it gets to the end but nothing more. Taskmanager shows a CPU usage of +/- 15%. I searched the net for answers but I only found two similar situations. One was due to the java heap size and another one due to tcp/ip problems. I checked both but the problem still persists. I really need Maple for my courses and you guys are my last resort. I'm running it on win7 64bit and I tried both 32 and 64bit Maple.

## Dirac Algebra using the Physics Package...

Hi,

I'm trying to set up the dirac algebra using the Physics package in maple 18. There are dirac gamma matricies (Dgamma) already specified, but I can't seem to manipulate their commutation relations.

So I've tried building my own:

restart;
with(Physics);

Setup(noncommutativeprefix = {gamma});

g[1] := gamma[1]; g[2] := gamma[2]; g[3] := gamma[3]; g[4] := gamma[0];

InverseMetric := rhs(g_[`~mu`, `~nu`, matrix])

Algebra :=  (a, b) -> %AntiCommutator(g[a], g[b]) = 2*InverseMetric[a, b];

Rules := Matrix(4, 4, Algebra);

Setup(algebrarules = Rules);

Error, (in Physics:-Setup) unable to set AntiCommutator(gamma[0], gamma[1]) = 0 because, taking into account {AntiCommutator(gamma[0], gamma[0]) = 2}, we would have gamma[0] and gamma[0] anticommutative and AntiCommutator(gamma[0], gamma[0]) <> 0

It seems like Maple can't handle the Dirac Algebra? Or have I done something obviously wrong?

Any help is appreciated.

Thanks

## How do I magnify text in menus, palettes, plots et...

Hi,

I use Maple on my laptop computer (windows 8.1) with a small screen. My problem is that the text in the menus, palettes, plots etc. are so small so I can´t read it. I have set Large toolbar icons under the menu tools-options-interface and I use the zoom buttom on the toolbar but this only magnify the text in a document. I also use the magnifying glass in windows, but I find it very inflexible. Is there any better solution to this problem?

Kind Regards

Leif Jonson

## Having trouble with Maple evaluating an integral....

Below is the function that I have.

f := (t-1)^(1/3)

p:=2;

b[n] := 2/p*(Int(f*sin(2*Pi*n*t/p), t = 0 .. p))

I also included a picture below to show what it is doing. Some help would be greatly appreciated. All I need to know is why maple doesn't want to evaluate bn?

## How to get a procedure to return an output as a {s...

So if I have a procedure like

with(GraphTheory)

tneighbors := proc (G::Graph)

local numvertices::integer, i::integer, currentvertex;

numvertices := nops(Vertices(G));

for i to numvertices do

currentvertex := Vertices(G)[i];

if nops(Neighbors(G, currentvertex)) = 2 then print(currentvertex)

end if;

end do;

end proc;

How do I make it so the output gets returned as a set?

For example, if I do  twoneighbors(G); and get
1

7

4

How do I make it so the output is listed as a set like {1,4,7}? Thanks.

## find the domain of a function...

Hi Maple friends.

How can I find the domain of y=sqrt(3*x-5)? or of y=1/(x+2)^2?

When I open my file I got an error message says "there were problems during loading process"

and some of my text are missing.

Maple Worksheet - Error

## problem of numerical integration with method = _d0...

See AAAA.mw

The alpha and beta are 'randomly' chosen, both >0, to produce some values, hence a value for the target function to optimize.

I am having trouble to evaluate the expression in the middle of the calculation.

Sometimes, the 'chosen' alpha and beta works fine with 'method = _d01amc' for numerical integration. and such way is really "fast".

But sometimes, the the 'chosen' alpha and beta will fail. Even when both of them are perfectly defined. and the integral can be easily evaluated using Int() and then evalf().

So what's be best way to proceed?

Thanks,

casperyc

## Kronecker Delta in a Sum....

Consider the following sum:

We know that if k is between 1 and N, the result will be

and otherwise the sum is zero.

How can I tell maple to compute this sum in each case without giving numerical values to the parameters "N" and "k"?

Thanks. :)

## How to evaluate an array(Matrix) involve numerical...

If I were to evaluate a single numerical integral, I can use evalf( Int(,method = _d01amc)).

But when the expression say is created by a built in function, Student[VectorCalculus][Hessian], from a complicated expression involve integrals. The resulting expression does not have the option "method = _d01amc". It then takes a long time to evaluate.

See this "HE" variable for example. HE.txt

value(HE); # takes a long time

evalf(HE); # takes a long time

Is there a way to evaluate "HE", using ",method = _d01amc" wherever necessary?

Thanks!

## 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

=

=

## How to write a help file for a Maple package ...

I read this, but there was nothing on how to write a help associated with it.

Does anyone know where I can find it?

Many thanks,

casperyc