int(a(t)*b(t)+2*(diff(a(t), t))*(diff(b(t), t)), a(t));
Error, (in int) integration range or variable must be specified in the second argument, got a(t)
 

do not understand this error message,

how to integrate it?

Hello people in mapleprimes,
I have a question.
I appended two pictures where from the same code, two different orders of
expression appear.
How can I do for this so as not to get error messages?
The cause of this is simplify(%,symbolic) brings different order of term a__0^(-k)*F__D ahead of a parenthesis in a jpg.file and F__D*a__0^(-k) after
that parenthesis in another jpg.fine both in the line above that of  "dairihensu1."

In this case, What I can do?
Please help me.
Best wishes.

taro

my_code.mw

Original code is

e7_4:=F__D*(Omega+1)*beta/(beta-1) = F__I*a__D^(-k)*a__0^k+T^((sigma-k-1)/(-1+sigma))*F__D*phi^(k/(-1+sigma))+F__D;

a1:=beta=k/(sigma-1);
subs_free:=
  proc(a,b,c)
    local b1;
    b1:=isolate(b,c);
    subs(b1,a);
  end proc;
isolate(e7_4,a__D^(-k));simplify(%,symbolic);dairihensu1:=subs_free(%,a1,sigma);e7_5:=applyop(simplify,[2,4,1,3,2],dairihensu1);

A case without error.

A case with a error.

Hi everybody,

So today is 10-28-2016 and I explored Leyland Numbers for the first time, on Maple.  Please see my example file and let me know what your impression is.

x_to_the_yth_power_and_y_to_the_xth_power_take_4.mw

x_to_the_yth_power_and_y_to_the_xth_power_take_4.pdf

I have included a .pdf file so that the caual internet observer can also be aware of this information.

Regards,
Matt

Dear all,

I am creating an animation, and I was wondering if I can add a multiplier to my equation in a specific range.  So starting from z:=0.2 add a multiplier (z+1). The code I have so far is added. Does anyone know a code for this?

Kind regards

restart; 
with(plots); 
a := -1/2; b := 1/2; c := -2; d := 2; n := 20; 
g := proc (x) options operator, arrow; value(Int(sigma(t), t = 0 .. x)) end proc; 
sigma := proc (z) options operator, arrow; 2*sqrt(2*h^2-4*z^2)*z/h^2 end proc; 
h := i/n; 
for i to n do 
an2[i] := plot(sigma(z), z = -(1/2)*h .. (1/2)*h, view = [a .. b, c .. d], color = AQUAMARINE); 
an3[i] := plot(2*g(x), x = 0 .. (1/2)*h, view = [a .. b, c .. d], color = RED) 
end do; 
p := plots[display]([seq(an2[i], i = 1 .. n)], insequence = true); 
q := plots[display]([seq(an3[i], i = 1 .. n)], insequence = true); display(p, q)

Download from_net.mw

Pressure_loss.mw

Hey all, could someone pls help me with how i can setup the equation for f in my worksheet. It should look like v and Rey with 45 data points. I've tried alot but i can't seem to solve it mysefl. Is it because i solve and map at the same time?

Thanks

I want to run a specific color red outside and yellow inside on my equation here using MAPLE 8.00:

plot3d([(0.5+cos(5*u))*sin(2*v),(0.5+cos(5*u))*cos(2*v),0.5*(cos(5*u)-0.3*cos(15*u)+0.02*cos(25*v))],u=0..2*Pi,v=0..2*Pi,axes=FRAMED);

is there some one here can help me? thanks...here is the example of color I want Eg: 

I got a set like this one:

g:={{3, 4, 5}, {5, 12, 13}, {6, 8, 10}, {7, 24, 25}, {8, 15, 17},

  {9, 12, 15}, {9, 40, 41}, {10, 24, 26}, {12, 16, 20},

  {12, 35, 37}, {14, 48, 50}, {15, 20, 25}, {15, 36, 39},

  {16, 30, 34}, {18, 24, 30}, {20, 21, 29}, {21, 28, 35},

  {24, 32, 40}, {27, 36, 45}}

And i want to count how many time a number apper in this set. Like an example:

3 appear 1

4 appear 1

5 appear 2.

Thank for your reading, :)

Sorry for my bad english :)

i wrote this problem to solve 

Delta= Sum(j=1 to n)SUM(i=j to n)(pi*hj/Ad(t,ij)*Et,ij))

Where n=70,  G= ftj (t)/(4+0.85*t) , where (t =8, 16, 24,…….up to 8*n), hj= 13 for all j except j1 =18

Ad= (Aj+s(mij-1)), where Aj varies

Mij=ES/E(G),          where E(G)= 57sqrt(1000*G)

Download short.mw

Hi All,

I have a fucntion f(x,y,z) = exp(-x^2 -y^2 - z^4) and would like to plot the probabity density in real space. One method would be to randomly sample points in a grid based on f(x,y,z). The function f(x,y,z) is clearly peaked around x=y=z=0, so you would expect many points to lie around there. So the plot would look like a clump near (0,0,0) which gets less dense away from (0,0,0).

In the worksheet below, I sampled points from the Uniform distribution to file in the 3d-plot. I would like these points to be sampled from f instead, but am not sure how to do this.

Any help is appreciated,

Download Sample_Test.m

I have the following code in Maple 13:

SYS := {diff(T(x, t), t) = diff(T(x, t), x, x)};
IBC := {T(1, t) = 0, T(x, 0) = 1, (D[1](T))(0, t) = -exp(t)};
SOL := pdsolve(SYS, IBC, numeric, time = t, timestep = 1/10);
R := SOL:-value(output = listprocedure); temperature := subs(R, T(x, t));

It integrates the heat equation in the interval x=0..1 and it seems to work ok.
However, I have problems trying to obtain the temperature derivative at the boundaries (this is at x=0 and x=1). I'm using different commands and it seems the derivative is evaluated ok inside the domain but not at the boundaries.
If I try
fdiff(temperature(x, t), [x], {x = 1,t=0.5});

or

evalf((D[1](temperature))(1, .5));

I don't get any numerical answer. Any idea how I could obtain the value of the derivative at the boundaries?

Thanks in advance,

Javier

Hi!

Is there any possibility for taking the negative sign outside a function, like factorization of -1?

Say I have. 

,

How do i get this output?

Thanks!

> restart;

with(plots);

pr := .72; p := 0; n := [.5, 1, 1.5]; s := 0; a := .2; b := 0; L := [red, blue, green]; l := 0; k := 1;

for j to nops(n) do R1 := 2*n[j]/(1+n[j]); R2 := 2*p/(1+n);

sol1 := dsolve([diff(diff(diff(f(eta), eta), eta), eta)+f(eta)*(diff(diff(f(eta), eta), eta))+R1*(1-(diff(f(eta), eta))^2) = 0, diff(diff(theta(eta), eta), eta)+pr*k*f(eta)*(diff(theta(eta), eta))+R2*pr*k*(diff(f(eta), eta))*theta(eta)+(2*(a*(diff(f(eta), eta))+b*theta(eta)))/(1+n[j]) = 0, f(0) = 1, (D(f))(0) = b*((D@@2)(f))(0), (D(f))(1.8) = 0, theta(0) = 1+s*(D(theta))(0), theta(1.8) = 1], numeric, method = bvp);

fplt[j] := plots[odeplot](sol1, [eta, diff(diff(f(eta), eta), eta)], color = L[j], axes = boxed); tplt[j] := plots[odeplot](sol1, [[eta, theta(eta)]], color = L[j], axes = normal) end do; plots:-display([seq(fplt[j], j = 1 .. nops(n))]);

plots:-display([seq(tplt[j], j = 1 .. nops(n))]);

staganation_point1.mw
 

can we chage the axis sir ?? like  f'' vs eta to f'' vs lambda.

Download staganation_point1.mw

dear all,

how can I plot

 u:=(3*x-1)*(1-x):
v:=2*x*(1-2*x):

in (u,v)-plane

where x from 0..1

Hello everyone,

I am trying to solve a system of ODE's numerically but the problem is with the condition f(0)+g(0)=1.

Here is the system with the initial conditions,

restart:
ode1:=diff(f(x), x,x)+(f(x)+g(x))*diff(f(x),x)=0;
ode2:=diff(g(x), x,x)+(f(x)+g(x))*diff(g(x),x)=0;
ics:=f(0)+g(0)=1,D(f)(0) =0,D(g)(0) =1;
dsolve({ode1,ode2,ics},numeric);

which give an error

Error, (in DEtools/convertsys) invalid specification of initial conditions

The above system is a simplified form of a very complicated one.