In the link below I attempt to solve 2 trig series which are essentially equivalent as indicated by the numerical output of eq (5).  The series  represented by S13 & S14 has arguments of the trig functions that realizes that only the odd terms for k yield non-zero results.  The case represented S11 & S12 by makes no such presumption; nonetheless, all cases agree within reason numerically.  Now to find min/max values taking the derivative is needed which is simply done by removing the integral as indicated by Q1 through Q6.

Now resolving the roots works OK for Q6 because beta = 2*pi *t/T conveniently collapsed the numerator into factorable expressions.  Resolving the roots for Q3 did not work so well because what I think is that the expression in red has multiple roots so it only spits out t as the solution?  I expressed the angle alpha in terms of beta & probably need to resolve kappa to somehow get the expression in red to collapse into a factored expression, but I am not sure how to execute this.  When I solve for kappa I get ZERO.

Does anyone have suggestions?  Remember I demonstrated that both series are practically idendical numerically; hence, there derivatives should be as well as long as both series are well behaved functions.  So the solutions must be the same as well.

trig_series_solns.mw

can result ?

Please help me?

Hi Dears,

Let us consider the following polyhedral cone which is defined by 8 inequalities (also, x,y,z ≥0): 

1. y-z ≥0

2. 3y-2z ≥0

3. 2y-2z ≥0

4. x-2y+z ≥0

5. x-y ≥0

6. 2x-y ≥0

7. x-z ≥0

8. x+y-z ≥0. 

How can we deduce that the inequalities 3 and 4 may be define this polyhedral cone and the others are redundant?

How can remove the redundant inequalities for defining this polyhedral cone?

Is there any Maple command or function that recive these 8 inequalities and return inequalities 3 and 4? In fact, inequalities 3 and 4 are facets of this polyhedral cone. 

Thank you in advanced. 

Sincerely yours

Hi,

I am a little bit surprised by the result of the operation evalf[8](f(y)) in the piece of code that follows.
I was expected the answer to be 2.4494897, not 2.4494898.

Happily the sequence
res := f(y) ; evalf[8](res)
returns the expected result 2.4494897

I suspect the difference comes from some precedence of the operators (f and evalf) but I can't figure out what really happens

Could you enlight me please ?

Thanks in advance

with maple

How can in maple 2015? Help me?

hi every one

I need to rearrange the matrix variables after using collect command

R[3, 3] := collect(R[3, 3], z^2);
                                  2             
               (-cos(theta) + 1) z  + cos(theta)
sort(R[3, 3]);
                                  2             
               (-cos(theta) + 1) z  + cos(theta)

i want it to appear as z(1-cos(theta))+cos(theta) ,  can i use sort or sequence or there is another command to do this   ???

hi everyone,

i have attached a maple worksheet which you can see the issue...azido_displacement.mw
i think tittle says by itself... thanks in advance for taking the time to review and aswer me.

Download azido_displacement.mw

We’re kicking off 2018 right, with another Meet Your Developers interview! This edition comes from Erik Postma, Manager of the Mathematical Software Group.

To catch up on previous interviews, search the “meet-your-developers” tag.

Without further ado…

1. What do you do at Maplesoft?
   I’m the manager of the mathematical software group, a team of 7 mathematicians and computer scientists working on the mathematical algorithms in Maple (including myself). So my work comes in two flavours: I do the typical managerial things, involving meetings to plan new features and solve my team’s day to day problems, and in the remaining time I do my own development work.
    
2. What did you study in school?
   I studied at Eindhoven University of Technology in the Netherlands. The first year, I took a combined program of mathematics and computer science; then for the rest of my undergrad, I studied mathematics. The program was called Applied Mathematics, but with the specialization I took it really wasn’t all that applied at all. Afterwards I continued in the PhD program at the same university, where my thesis was on a subject in abstract algebra (Lie algebras over finite fields).
    
3. What area(s) of Maple are you currently focusing on in your development?
   I’ve spent quite a bit of time over the past two years making the facilities for working with units of measurement in Maple easier to use. There is a very powerful package for doing this that has been part of Maple for many years, but we keep hearing from our users it’s difficult to use. So I’ve worked on keeping the power of the package but making it easier to use.
    
4. What’s the coolest feature of Maple that you’ve had a hand in developing?
   This was actually working on a problem in a part of the code that existed long before I started with Maplesoft. We have a very clever algorithm for drawing random numbers according to a custom, user-specified probability distribution. I wrote about it on MaplePrimes in a series of four blog posts, here. I’ve talked at various workshops and the like about this algorithm and how it is implemented in Maple.
    
5. What do you like most about working at Maplesoft? How long have you worked here?
   I love working at the crossroads of mathematics and computer science; there aren’t many places in the world where you can do that as much as at Maplesoft. But the best thing is the people I work with: us mathematicians are all crazy in slightly different ways, and that makes for a very interesting working environment.
    
6. Favourite hobby?
   Ultimate frisbee. I captain a mixed (i.e., coed) team called The Clockwork. (We play in orange jerseys – it references the book/movie A Clockwork Orange.) We play in a couple of local leagues, and some of the other members also work here. We don’t win much – but we work hard and have fun!
    
7. What do you like on your pizza?
   Mushrooms. Mushrooms on everything!
    
8. What’s your favourite movie?
   Probably Black Book, a dark movie about the Dutch resistance in the second world war from 2006, directed by Paul Verhoeven. I think what I like best about it is that it highlights the moral shades of grey in even so morally elevated a group as the resistance.
    
9. What skill would you love to learn? Why?
   I’d love to learn to speak Russian! I’m trying, but I have a very hard time with it. It would allow me to communicate with my in-laws more easily; they speak Russian.
    
10. Who’s your favourite mathematician?
    Oh, so many to choose from! I’m torn between:

• Ada Lovelace (1815-1852), known as the first programmer.
• Felix Klein (1849-1925), driving force behind a lot of research into geometries and their underlying symmetry groups.
• Wilhelm Killing (1847-1923), a secondary school teacher who made big contributions to the theory of Lie algebras.

Or wait, can I choose my wife?

FLRW_Metric.mw

I have been tasked with calculating all the non-vanishing Christoffel symbols (first kind) of a metric and have done these long-hand using the Lagrangian method and shown my working. However, for peace of mind I would like to run the metric through Maple and double-check that it returns the same answers (going back through my calculations if I have missed anything). I have attached the code I have written at the bottom.

I have no trouble defining the metric and the manifold but I receive an error message when I try to compute the Christoffel symbols 'improper op or subscript selector'. Could someone point out where I have made a mistake. The metric is the FLRW metric if that helps.

with(DifferentialGeometry):with(Tensor);

g1:=evalDG(-(dt)^2 +a(t)^2*((dx)^2+(dy)^2+(dz)^2)/(1+(k/4)*(x^(2)+y^(2)+z^2))^2 );

C1:=Christoffel(g1, "FirstKind");

Please take a look at the attached document, a partial design for a power supply I'm working on.  I find I am spending a lot of time reformatting results with units to look as nice as what you see here.  For every result, I need to do Units Formatting, change to a sensible unit like uH instead of 10^-6 H, and then do Numeric Formatting to change the number to show just three significant digits.  That requires from 0 to 2 decimals, in fixed point.

This is the way engineering documents should look.  You want to see a fixed point number from 1.00 to 999, with a certain number of significant digits (not decimal points), and have the unit scaled accordingly.  You want to see 12.3 uA, not 1.23402 x 10^-5 A.

I would like to see Maple add "N significant digits" to its Numeric Formatting options and auto-scale results with units to the appropriate multiplier.  If I could set that as my default result formatting it would save a huge amount of work.  Often as a design progresses the multiplier will change, also.  A result may initially come out in mA but later change to uA.  Not only do I have to do them all manually now, but I have to go back and change them.  Automating all that would be a great help.

(You may also notice that my vector results with units are not scaled like I describe here.  If anyone can tell me how to do that I would appreciate it.  Otherwise, it looks like a bug to me.)

Example_Document.zip

Plot3d in this worksheet calls a procedure which conditionally returns the values for a parametrically defined ellipsoid, but the plot command fails. However the procedure passes the correct list of parametric values when it is called directly.

Is there a way to call a procedure within plot3d which successfully plots a parametrically defined surface?

Plot3d_proc_parametric.mw

Can we overide Maple default dot derivative with 'tau' instead of 't'?

When I use listcontplot, the tickmarks on the axis show the ordinal of the point plotted, so if I have 20x50 points, it shows (1 to 21)x(1 to 51).

Is there any way to reescalate the axis to show the actual units of the points?, so for example (0.3 to 0.7)x(2.2 to 3.7).

Thanks.

Can anyone figure this out? Just getting solutions may have been lost :/ 

 

Kabel FeAl35
restart;
r[FeAl] := .51;
x[FeAl] := I*.38;
c[FeAl] := 9.5*10^(-9);
l[12] := 14;

PEX 240 Al
r[PEX] := 0.8e-1;
x[PEX] := I*.32;
c[PEX] := 11.4*10^(-9);
l[23] := 5;

Beregner Admittanser
X[12] := x[FeAl]*l[12];
R[12] := r[FeAl]*l[12];
Z[12] := R[12]+X[12];
X[23] := x[PEX]*l[23];
R[23] := r[PEX]*l[23];
Z[23] := R[23]+X[23];
C[12] := c[FeAl]*l[12];
C[23] := c[PEX]*l[23];
X[C1] := -I/(50*Pi*C[12]);
X[C2] := -I/(50*Pi*C[23]);
YC1 := 1/X[C1];
YC2 := 1/X[C2];
Y12 := 1/Z[12];
Y23 := 1/Z[23];
Y11 := Y12+YC1;
Y22 := Y12+YC1+Y23+YC2;
Y33 := Y23+YC2;
Y13 := 0;
Y := Matrix([[Y11, -Y12, -Y13], [-Y12, Y22, -Y23], [-Y13, -Y23, Y33]]);
PL2 := 5000000;
PL3 := 3000000;
PG3 := 2300000;
PF := .98;
P2 := -PL2;
Q2 := P2*tan(arccos(PF));
P3 := PG3-PL3;
Q3 := P3*tan(arccos(PF));
V1 := 22000;
eq1 := conjugate(V2)*V2*V2 = ((P2-I*Q2)*V2-conjugate(V2)*V2*(V1*Y12+V3*Y23))/Y22;
eq2 := conjugate(V3)*V3*V3 = ((P3-I*Q3)*V3-conjugate(V3)*V3*(V1*Y13+V2*Y23))/Y33;
solve({eq1, eq2}, {V2, V3});
 

I know it is very basic but…: I need the remainder of a division. I read about the "mod" operator in the Maple guide but I could not understand if it is what I need and if it works like it does in some other programming environments (i.e. Xojo).

Could you help me and, in case it's not what I need, tell me how to get said remainder?

Thank you