Hi everyone,

I converted a code from Maple 18 to Fortran 77 but the code is badly cut, for instance:

cg = -(F * h * p ** 2 - F * h * q ** 2 + 0.2D1 * F * k * p * q + c
     #os(F) * sqrt(-e ** 2 + 0.1D1) * p ** 2 - cos(F) * sqrt(-e ** 2 + 0.

Is there an option which can force the line cut to be done in an optimized way?

Thank you very much for your help!

Dear All,

 We have a long equation , we need to find a laplace transform for that eq. I found the command as ilaplace.  But its not getting executed.

 Any specific comments../ help..

regards

when the kummerM function equal to 0?????

or

-(((beta*eta^2-(1/2)*beta+1)*p^2-(1/2)*beta^3)*KummerM((1/4)*((-beta+2)*p^2-beta^3)/p^2, 1, beta*eta^2)+(1/2)*KummerM((1/4)*((-beta+6)*p^2-beta^3)/p^2, 1, beta*eta^2)*((beta-2)*p^2+beta^3))*exp(-(1/2)*beta*eta^2)/(p^2*beta)=0

how solve this equation unitage beta?

I'm trying to solve a system of 4 ODE's.

however I have 4 equations and six unknowns. I dont know how else to describe the functions a,b,c,d

cause these just represent vector valued functions at points (x1,y1) and (x2,y2) where i have chosing (x1,y1)=(-1,0) and (x2,y2) = (1,0)

I have that

dx1/dt = (u,v)

dx2/dt=(f,g)

I know that if i graph these functions I should get vertical lines, but I keep getting circles if I instead consider a(t) to be x(t) and b(t) to be y(t)...

I need to solve this system and plot it but i am misinterpreting something somewhere..

I have the system:

Update:

{-1/2 < 2*f*(1/53)+7*g*(1/53), 3/106 < 7*f*(1/53)-2*g*(1/53), 2*f*(1/53)+7*g*(1/53) < -37/106, 7*f*(1/53)-2*g*(1/53) < 1/2}

which I wish to solve over integers but isolve() gives me "Warning, solutions may have been lost and no solutions". The solutions exist and are {[f =0, g = -3] || [f = 1, g = -4], [f = 1, g = -3] || [f = 2, g = -4]}, but I cannot obtain them with Maple. Could you tell me what is wrong and how I should treat this kind of problems in the future, please.

Mathematica 10.0

Reduce[{-1/2 < 2*f*(1/53) + 7*g*(1/53), 3/106 < 7*f*(1/53) - 2*g*(1/53), 2*f*(1/53) + 7*g*(1/53) < -37/106, 7*f*(1/53) - 2*g*(1/53) < 1/2}, {f, g}, Integers]

(f == 0 && g == -3) || (f == 1 && g == -4) || (f == 1 &&
   g == -3) || (f == 2 && g == -4)

Maple

isolve({-1/2 < 2*f*(1/53)+7*g*(1/53), 3/106 < 7*f*(1/53)-2*g*(1/53), 2*f*(1/53)+7*g*(1/53) < -37/106, 7*f*(1/53)-2*g*(1/53) < 1/2});
Warning, solutions may have been lost

Gentlemen

As seen on tv.

Having issues with animating the movement of two fielders, (25m apart on a straight line) when a baseball is struck towards them. they're on the y axis when they should be on the x.... and they should be green and brown dots, not lines.....

BaseballBallistics.mw

The mechanism of transport of the material of the sewing machine M 1022 class: mathematical animation.   BELORUS.mw 

 PS. I see my proof needs an additional explanation. The DirectSearch command establishes the only both local and global  maximum of F is located at z= -1.98*10^(-13) up to default error 10^(-9). After that  the series command confirms a local maximum at z=0. Combining these, one draws the conclusion that the global maximum is placed exactly at z=0 and equals 2. In order to confirm that the only real root of F=2 at z=0  is found approximately and exactly by the DirectSearch.

Download maxi.mw

Hello!

I am calculating the temperature of a rod which has one end at the temperature T₁ and the other end at T₂ and it's evolution. We were already given the formula for the numeric calculation and after a short while I managed to obtain a small program that would calculate the temperature of each segment of the T(x,t) grid:

>restart: with(plots): nx:=20: tmax:=50: T1:=1: T2:=10: L:=1: k:=1: rho:=1: cp:=1: chi:=k/rho/cp: h:=L/(nx-1): t:=1e-3:
>for k from 0 to nx do T(k,0):=T1 od:
for w from 1 to tmax do
T(0,w):=T1: T(nx,w):=T2:
for q from 1 to nx-1 do
T(q,w):=T(q,w-1)+chi*t/h^2*(T(q+1,w-1)+T(q-1,w-1)-2*T(q,w-1));
od: od:

With L the Length of the rod, t and h the time and space increment [h=L/(nx-1), where nx is the number of intervals we divide the x-axis, although I'm not quite sure the '-1' should be there], chi a constant different for each rod and tmax total time we want to calculate. The formula from the 5th line was given to us, so in that part there is no mistake.

Up until here everything works perfectly fine.

Now I want to be able to draw this and here is where all the problems appear. I want to draw this in a 2D graph with position in the x-axis and time in the y-axis. I have tried "densityplot(T(x,y),x=0..nx,y=0..tmax)" which would seem to be the logical whay to continue this. As I understand it, this plot would draw an nx times tmax grid and colour the whole plpot black-white acording to the maximum and the minimum value (as shown in the maple help page of this plot).

However, when I do this a black square appears (or red if I add colorstyle=HUE). I have tried a lot of things and none seemed to work.

I would also like to be able to draw the isotherms on the plot but that is secondary.

I am pretty new to Maple. I have studied the most basic things but don't really understand the whole complexity of this program. Thanks a lot in advance and forgive my faulty english,

Enrique

Hi, currently im using maple 15

the coding did work but it is not the same with the answer
here, i attach the coding with the answer

coding:
derivation := proc (A, n)
local i, j, k, t, s1, s2, m, D, sols, eqns, Andre;
eqns := {};
D := matrix(n, n);
Andre := matrix(n, n);
for i to n-1 do
for j from i+1 to n do
for m to n do
s1 := sum(A[i, j, k]*D[m, k], k = 1 .. n);
s2 := sum(A[k, j, m]*D[k, i]+A[i, k, m]*D[k, j], k = 1 .. n);
eqns := `union`(eqns, {s1 = s2})
end do end do end do;
sols := [solve(eqns)];
t := nops(sols);
for i to t do
for j to n do
for k to n do
Andre[k, j] := subs(sols[i], D[k, j])
end do end do;
print(Andre)
end do end proc

the maple result showing:

> AS1 := array(sparse, 1 .. 2, 1 .. 2, 1 .. 2, [(1, 1, 2) = 1]);

> derivation(AS1, 2);
[D11 0]
[D21 D22]

> AS2 := array(sparse, 1 .. 2, 1 .. 2, 1 .. 2, [(1, 1, 1) = 1, (1, 2, 2) = 1]);
> derivation(AS2, 2);
[0 D12]
[D21 D22]

the maple should showing

> derivation(AS1, 2);
[D11 0]
[D21 2D11]

> AS2 := array(sparse, 1 .. 2, 1 .. 2, 1 .. 2, [(1, 1, 1) = 1, (1, 2, 2) = 1]);
> derivation(AS2, 2);
[0 0]
[D21 D22]

please help., thank you

how to field plot this system?

restart;
with(Physics[Vectors]);
with(DEtools);
with(VectorCalculus);
eq2 := ...;
eq3 := ...;
eq4 := ...;
with(DynamicSystems);
sys := DiffEquation([eq2 = t, eq3 = t], inputvariable = [b(t)], outputvariable = [a(t), c(t)]);
ts := .1;
in_t := t;
sol := Simulate(sys, [in_t]);

with(DEtools):
dfieldplot([...],[a(t),b(t),c(t)],t=−2..2,a=−1..2,b=−1..2,c=−1..2,arrows=SLIM,color=black,dirfield=[10,10]);

>assume(x>0, n>0):int(x^n*ln(x)^n,x);

I_Mariusz

Hello, I have a question.  I don't know why, but results of my calculations can't be saved in raschet document. This document excists, but there is no information in it! And I have an error with floating point format. How to solve that problems?

> restart;
> Digits := 5;
> NULL;
> NULL;
> NULL;
> NULL;
> NULL;
> ScS0 := P/(phi*f*kc*k0*deltad*Bm*etat);
> NULL;
> NULL;
> Sc := sqrt(ScS0);
> A := sqrt(Sc);
> B := A;
> NULL;
> mue := mu0*mur/(1+mur*dzet/lm);
> lm := 2*(LCA-A+(LC0+A))+dzet;
> NULL;
> LC0 := 3*A; LCA := .4*LC0; LD := .9*LC0;
> NULL;
> NULL;
> w1 := EE/(2*Pi*f*Bm*Sc);
> Lm := mue*w1^2*Sc/lm;
> ;
> I11 := sqrt((w2*Id/w1)^2+I0^2);
> ;
> NULL;
> ;
> h1 := sqrt(RAT*I11/deltad);
> ;
> h2 := sqrt(RAT*Id/deltad);
> NULL;
> A := .6;
> Ud := 35000;
> Id := 413;
> R := Ud^2/P;
> P := Ud*Id;
> P1 := P/eta;
> R1 := EE/I11;
> EE := 110000;
> I0 := EE/(2*Pi*f*Lm);
> w2 := w1*sqrt(P*R)/EE;
> mu0 := 4*Pi*10^(-7);
> mur := 1000;
> f := 50;
> k0 := .25;
> kc := .98;
> deltad := 0.3e7;
> Bm := 1.45;
> etat := .98;
> eta := .95;
> RAT := 1;
> dzet := 0.1e-3;
> phi := .5;
> W1 := evalf(w1);
324.55
> LLm := evalf(Lm);
13.407
> W2 := evalf(w2);
103.26
> evalf(lm);
7.2457
> evalf(LC0);
2.5877
> evalf(LCA);
1.0351
> Imax := evalf(I0);
26.117
> P1;
7
1.5215 10
> Rd := evalf(R);
84.746
> Bmm := evalf(mue*w1*I0/lm);
1.4500
> hâ := (.9*LC0*1000)/(w2+1)-4;

> evalf(hâ);

h￢
> Pred := Id/deltad;
> evalf(Pred);
0.00013767
> NULL;
> NULL;
> ll := hâ*(w2+1)+4*w2;
> NULL;
> a := am*nâ/nx;
> NULL;

> Pol := Vit*nâ;
> am := 5.1;
> am := 5.1;
> nâ := 4;
> evalf(a);
20.4
----
nx
> Vit := 35.19;
> evalf(Pol);
140.76
> plotnToka := Id/Pol;
> evalf(Id/Pol);
2.9341
> NULL;
> I1 := evalf(I11);
133.98
> NULL;
> evalf(mue);
0.0012395
> NULL;
> evalf(EE/I11);
821.02
> NULL;
> pr := "%";
"%"
> fd := fopen("C:\\Users\\Ñåìåí\\Desktop\\ÍÈÐ\\raschet4.ms", WRITE); fprintf(fd, "E=%g;Ud=%g;Imax=%g;P=%g;FR=%g;A=%g;B=%g;LC0=%g;LD=%g;LCA=%g;R=%g;BM=%g;", EE, Ud, Imax, P, f, A, B, LC0, LD, LCA, Rd, Bm); fprintf(fd, "\n %s P=%g;Id = %g;Bm=%g;I1=%g;Bmm=%g", pr, P, Id, Bm, I1, Bmm);
Error, (in fprintf) number expected for floating point format
Error, (in fprintf) number expected for floating point format
> fprintf(fd, "\n %s W1 = %g; W2 = %g; Lm=%g; Sc=%g; dzet=%g", pr, W1, W2, LLm, Sc, dzet);
Error, (in fprintf) file descriptor not in use
> fclose(fd);
Error, (in fclose) file descriptor not in use

I have a system of PDEs with 3 dependent variables (U, V, W) and 3 independent variables (x, y, t).

I need an explicit numerical solution, i.e., a table with the values of U, V and W, corresponding to several values of x, y and t.

Can anybody help me?

>tekssifer:="Qnuux*#Huh";

tekssifer:=Qnuux*#Huh

Hi, how i need to continue my command to get the size of tekssifer in bytes? 

Thank you~=]]