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Hello! I'm really craving for a piece of advice from you pros.
For simplicity's sake let's start with this made-up system.

where

and

Here is solver options with pair of events to get idea about what I want.

Plot of solution



For my purposes it's essential to restrict variables m and D(fi1)(t), D(fi2)(t). While it's very convenient to use piecewise() operator in first case with m, I simply can't find working method for second.

I've tried various events for dsolve, but they trigger only once and I failed to provide continuous restriction on the derivatives in question.

That's what I need in the end:


If there's a way to obtain this result, please, don't make secrets of it :) Thank you in advance!

Hi!

 

I was trying to obtain the field equations for the QED Lagrangian and I was not sucessfull.

 

All my calculations are equal to 0.

 

Can someone give a hand?

 

QED.mw

 

Thanks a lot.

Hi

I have the following functional

I was wondering how I would evaluate the following in Maple

Thanks

James

 

 

Hi....how can i multiply the 9*4 matrix on the left side of this table to the 9*1 vector on the right side of it (last column) with a kind of product of cells that results a 9*4 matrix made up of cells like this one's [(a,b,c,d)⊗(e,f,g,h)=(ae,bf,cg,dh)]

can anyone help me please?

 

SO

ST

WO

WT

Weight

C1

(0.55,0.67,0.78,0.89)

(0.7,0.8,0.8,0.9)

(0.767,0.867,0.93,0.967)

(0.72,0.83,0.83,0.93)

(0.7,0.8,0.8,0.9)

C2

(0.67,0.78,0.89,0.97)

(0.8,0.9,1,1)

(0.73,0.83,0.867,0.93)

(0.66,0.76,0.79,0.90)

(0.8,0.9,1,1)

C3

(0.78,0.89,0.89,1)

(0.8,0.9,1,1)

(7.67,8.67,9.3,9.67)

(0.55,0.66,0.69,0.79)

(0.767,0.867,0.93,0.967)

C4

(0.78,0.89,0.89,1)

(0.06,0.13,0.167.0.267)

(0.8,0.9,1,1)

(0.76,0.86,0.90,0.97)

(0.43,0.53,0.567,0.667)

C5

(0.78,0.89,0.89,1)

(0.8,0.9,1,1)

(0.06,0.13,0.167.0.267)

(0.76,0.86,0.90,0.97)

(0.73,0.83,0.867,0.93)

C6

(0.74,0.85,0.93,1)

(0.67,0.767,0.83,0.9)

(0.73,0.83,0.867,0.93)

(0.62,0.72,0.83,0.90)

(0.8,0.9,1,1)

C7

(0.59,0.70,0.74,0.85)

(0.567,0.667,0.73,0.83)

(0.667,0.767,0.83,0.9)

(0.69,0.79,0.86,0.93)

(0.067,0.1,0.2,0.3)

C8

(0.74,0.85,0.93,1)

(0.7,0.8,0.9,0.93)

(0.567,0.667,0.73,0.83)

(0.79,0.90,0.97,1)

(0.73,0.83,0.867,0.93)

C9

(0.70,0.81,0.85,0.96)

(0.7,0.8,0.9,0.93)

(0.7,0.8,0.8,0.9)

(0.59,69,0.76,0.86)

(0.53,0.63,0.667,0.767)

Hye, have a good day everyone..

can anyone know why I got this error? :(second_grade.mw

Error, (in dsolve/numeric/bvp/convertsys) unable to convert to an explicit first-order system


Here I have attached the file. thank you in advance :)

Why can't I run a produce on the Maple IDE? I can't add Maple environment to Maple IDE. The error is this.

License expires in 29 days
|\^/| Maple 18 (X86 64 WINDOWS)
._|\| |/|_. Copyright (c) Maplesoft, a division of Waterloo Maple Inc. 2014
\ MAPLE / All rights reserved. Maple is a trademark of
<____ ____> Waterloo Maple Inc.
| Type ? for help.
Error: EnvUtils:-KernelSummary("could not validate license %1, required by %2. Please check the Install.html file under the toolbox directory for instructions on how to activate a license.\nLicense manager error: %3")
memory used=0.7MB, alloc=8.3MB, time=0.11

what means the command that `linsolve` and 

when

a:=matrix([[a1,a2],[b1,b2]])

b:=vector([c1,c2])

c:=transpose(a)

linsolve(c&*a,c&*b)

&* <<--- what is it

 

hi , kindly guide me how to draw combine graphs for velocity profile at different values of one parameter.  For example we have 3rd order ODE and A is parameter that is multiple of equation. now we want to see the effects of that parameter on this 3rd  order ODE.  Now  how can i sketch the  combine graph of Df(o) at A=1, 2, 3. (for example.)

 

thanks 

I need to make a lot of similar calculations and wonder if it can be done in a smart way in Maple. Microsoft Excel is perfect for this kind of calculations, because you can downcopy cells. I would like to do everything in Maple, if possible, though. I have a number of points A, B, C, D, E, ... , which all lie on various circles in the plane. For every point radius and angle is given, so actually you can say that every point is delivered with polar coordinates. I want to have their rectangular coordinates. 

Maybe I could deliver their radii in a list and their angles in degrees in another list?

r:=[12,56,29,...., 78]:

v:=[15,45,75,..., 102]: 

......

I need to be able to refer to a certain point thorugh an index. At best it would be A, B, C, ... , but 1, 2, 3, ... will be acceptable. So in the end I need to be able to access say x_C and y_C or x_3 and y_3 (understood as index lowered). I hope someone can help me do the task in a nice a efefctive way.

NB! Maybe you have a solution, which involve transformation from polar to rectangular coordinates. That will be nice, but please also tell me how it can be done from scratch, because I want to be able to know about handling many points at once for other purposes, when the function is not r*cos(v), but an arbitrary function.

Regards,

Erik

Is there any some kind of environment variable(or command,package, anything...) that I can play with to tell maple consider all the constrants implied by the given expression

 

For Example, I want to simplify the following equation(this equation's final form is "0=0" if you take the implied constraints into account.)

 "(4*a^3*b)^(1/2)/(-(a/(4*b))^(1/2))+(4*a^3*b*(4*b/a))^(1/2) = 0" 

in real domain and this equation implies that variable a and b are both negative or positive because of the sqrt operation. And neither a nor b should be zero because they are part of a fraction's denominator.

but if i simply tell maple to simplify this equation, all the constrants will be ignored by maple, even if i use RealDomain package.

 

My problem is the following; Let's say that I want to make a simple program of designing of a steel beam. In order to do so, there is a respectable number of parameters that have to be taken into account - forces, geometrical characteristics etc -. So for example, I have an excel file that has the following rows

1) A row of variables  :                          LENGTH   MOMENT_OF_INERTIA   AXIAL_FORCE    HEIGHT_OF_SECTION
 
2)A row of a value for each one variable :      5                556                       130                       300


the traditional approach in maple to intoduce these values to the program would be:

LENGTH:=5
MOMENT_OF_INERTIA:=556
AXIAL_FORCE:=130                etc etc

and then when for example we write

MOMENT_OF_INERTIA/LENGTH       we get

556/5=111.2

..but for problems like this the variables may be 50 in number, even more.. and it would be very timeconsuming to define all these parameters one by one..
so what I have been looking for so much these days is a predefined maple procedure - if there is one.. - that takes a matrix which we have created in advance and that includes all the names of the variables that we want to have in the problem - let's name it VARIABLES - takes as well a matrix that we also have created in advance and includes the value that we want each of our variables to get in the problem - let's name it VALUES - and make the correspondense automatically, so as to when we introduce an epression in maple thereafter, like     MOMENT_OF_INERTIA/LENGTH, when we press enter to get  556/5=111.2  (and not just a reproducing of what we already wrote , MOMENT_OF_INERTIA/LENGTH ..).. Do you think that there is an easy way to do so??

many thanks in advance!

I use Maple 15 to calculate some (nasty) integrals at my university. Because our university also offers a server on which I can run my Maple program, I would like to do that. (instead of occupying a workspace). But at the computer on my workspace the integrals are evaluated fine, but on the server the integrals are just returned with no numerical evaluation.

I constructed a MWE to look where it goes wrong. I set the printlevel to 25 so I could see what was going on. The MWE was suprisingly simple, on both machines (via ssh) I executed within maple:

evalf(Int(1/sqrt(x), x=0..2))

This of course would normally just give 2*sqrt(2). On my workplace-pc it worked fine and it found 2.828427125. The server just returned the integral. After looking at the steps, they where both exactly the same until the following part:

Workplace-PC:

         General_flags := {_NoNAG, _DEFAULT, _NoMultiple}

            NAG_methods := {_d01ajc, _d01akc, _d01amc}

                        Method := _DEFAULT

                          HFDigits := 15

                                       -12
                        HFeps := 0.1 10

                                            -9
                    HFeps := 0.5000000000 10

   oldEvents := overflow = default, division_by_zero = default

                         callNAG := true

                            fcns := {}

                  result := 2.82842712474618807

Server:

        General_flags := {_NoNAG, _DEFAULT, _NoMultiple}

           NAG_methods := {_d01ajc, _d01akc, _d01amc}

                       Method := _DEFAULT

                         HFDigits := 15

                                      -12
                       HFeps := 0.1 10

                                           -9
                   HFeps := 0.5000000000 10

   oldEvents := overflow = default, division_by_zero = default

                         callNAG := true

                           fcns := {}

       overflow = exception, division_by_zero = exception

It seems that the server has a problem with the singularity and thus throwing an exception, but I just don't get why. The Maple-versions are both the same.

Does somebody know what this could be?

This might be a ridiculous question, but what is the easiest way to check the monotonicity of a function? I didn´t find anything helpful in the Maple Help, so maybe one of you could give me a nudge here :)

the following cmd gives me three 3 solutions: -1, 1,sqrt(2), even if I specificlly assume that a is not equal to neither 1 or -1....

([RealDomain[solve]((1/(a-1)-1/(a+1))*(2*a^2-2)/a = 4/surd(2, 2), useassumptions = true)] assuming a <> 1, a <> -1

 

why does this wired thing happen?

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