Maple 18 Questions and Posts

These are Posts and Questions associated with the product, Maple 18

hello my friends

I have a critical problem to solve below the system of differential equations

-(9/14)*R(t)^(19/14)-(285/196)*(diff(R(t), t, t))/R(t)^(9/14)+(2565/2744)*(diff(R(t), t))^2/R(t)^(23/14) = -k*(4*lambda+1/a(t)^3)

and R(t) = 6*((diff(a(t), t))^2/a(t)^2+(diff(a(t), `$`(t, 2)))/a(t))

I need to find form of a(t) numerically from set of differential equatios

plz help me as soon as possible

This is an example, the program gave me functions _F as outputs and i want to see what F is.

This is an example.

Thanks.

 

Hi, I am using fsolve to find the roots x of a nonpolynomial expression f(x,a) = 0, using a loop for do to vary the values of the parameter a in small identical steps. At some stage, fsolve cannot find a solution. According to the Maple help, in this case fsolve returns a NULL sequence. I would like to know how to use the fact that fsolve cannot find a solution to break the loop with an if-then statement. 

Dear all,

In Maple 18, I type the following three lines and I wonder how I can then resize the resulting displayed window:

with(plots):
p1:=plot3d(x*y,x=-1..1,y=-1..1):
display(Array([p1]))

Any idea?

Hi all, since I cannot use Latex over here I try to formulate as good as possible. Suppose we have the standard integral from a to b of a function f(x), which is equal to:

h * sum (k=1 to N) [ck f(a+kh)] +O(hp), where h=(b-a)/N+1, an p(N)>= N+1;

Would it be possible to write a procedure to evaluate the coefficients ck , k=1,2,3..N and P(N)

Perhaps a stupid question, because I don't know if it is possible.

Best wishes, Math

Hello,

I am a beginner with Maple. I had some basic tutorials. In fact I want to solve a first order differential equation with non-constant coefficient:

Can you really tell me what are the steps to follow in Maple 18 in order to solve this equation. I didn't find any tutorial or work that deals with variable coefficients.

Thank you in advnace.

Using the learning sequence as an alternative to learn problems related to "balance of a body" is shown in this video; thanks to the kindness that Maple offers us in its fundamental programming syntax.

Balance_of_a_body_with_learning_sequence.mw

Lenin Araujo

Ambassador Of Maple

 

 

I have a 2 dimensional array with variable length. I want to extract the number of elements of each row. For example What is the number of element in x(1,i)?

Hi everyone, I am trying to plot field lines but I face problem in plotting field plot. kindly help me if anyone can do it. Find the code in the attached file. Thank you.

Field_lines.mw

tomleslie 2300Mohsen 20 @Carl Love @Markiyan Hirnyk @maple fan 175 @asa12 405  @Adri van der Meer 1253 

Hi, i want to investigate  chaos for the problem , cantilever beam under random narro band excitation, but the code has errors .the code is this:

      restart:with(plots):      h:=1: Omega:=(0..376):alpha1:=617.2:alpha2:=1.02*10^(8): c:=.002:k:=18.4:  step:=0.1:imax:=376:  for i from 0 to imax do;  Omega[i]:=i*step:   f:=evalf(solve({((-a*Omega[i]^(2)+alpha1*a+3/(4)*alpha2*a^(3)+1/(4)*k*Omega[i]^(2)*a^(3)-(3)/(4)*k*Omega[i]^(2)*a^(3))^(2)+(c*Omega[i]*a^())^(2))=h^(2),a>0}));  ff[i]:=((rhs(f[1]))^(2))/(2):  end do:   l1:=[[Omega[n],ff[n]] $n=0..imax]:  p1:=plot(l1, x=0..3,y=0..1,  style=point,symbol=solidcircle,symbolsize=4,color=red):    jmax:=914: f1:=array(377..914):f2:=array(377..914):f3:=array(377..914):Omega1:=array(377..914):  for j from 377to jmax do;  Omega1[j]:=j*step:   fff:=evalf(solve({((-a*Omega1[j]^(2)+alpha1*a+3/(4)*alpha2*a^(3)+1/(4)*k*Omega1[j]^(2)*a^(3)-(3)/(4)*k*Omega1[j]^(2)*a^(3))^(2)+(c*Omega1[j]*a^())^(2))=h^(2),a>0}));  f1[j]:=((rhs(fff[1,1]))^(2))/(2):f2[j]:=((rhs(fff[2,1]))^(2))/(2):f3[j]:=((rhs(fff[3,1]))^(2))/(2):  end do:   ll1:=[[Omega1[n],f1[n]] $n=377..jmax]:  pp1:=plot(ll1, x=0..10,y=0..1,  style=point,symbol=solidcircle,symbolsize=4,color=red):    ll2:=[[Omega1[n],f2[n]] $n=377..jmax]:  pp2:=plot(ll2, x=0..10,y=0..1,  style=point,symbol=solidcircle,symbolsize=4,color=red):    ll3:=[[Omega1[n],f3[n]] $n=377..jmax]:  pp3:=plot(ll3, x=0..15,y=0..1,  style=point,symbol=solidcircle,symbolsize=4,color=red):       plot({  seq(seq(p1), seq(seq(pp1),seq(seq(pp2),seq(seq(pp3))  },style=point,title=`Pitchfork Diagram`);  Thanks for your help

Dear all,
When I try to simplify the expresion z+conjugate(z) I get, as expected, 2*Re(z).

The problem arises when I try to do the same with a more complicated expression as z1*conjugate(z2)+conjugate(z1)*z2. Trying to simplify this Maple only give me back the expression with nochange. The expresion is equivalent to the first example so I expected to get 2Re(z1*conjugate(z2)).

Does anybody know how to solve this problem?
Thank you in advance!

Dear All

Is it possible to change the position of labels so that they do not overlap with curves of plots? Please see the attached file in which I want to shift label for vertical axes to slightly left and label for horizontal axes to the slightly right.

Plot_Label.mw

 

Hi Dears,

I installed Maple 15 and 18 on my PC. But, when I want to use the PolyhedralSets package the following error is appeared. Is this package only on Maple 2015?

 

With the bests.

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.

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