MaplePrimes Commons General Technical Discussions

The primary forum for technical discussions.
I'm converting an expression to optimized Matlab code, and some key parentheses were left out of the final expression. Is this a known bug? I'll include the offending code below:

W1 := (-5+6*b*c*d^2+5*a*b^3*c*d+5*a*b*c^3*d+a*b*c*d+a*b^3*c^3*d-2*a*b*c*d^3-4*a*b^2*c^2*d-b^4+6*b^2+6*c^2-c^4+4*d^2-2*b^2*c^2*d^2-3*b^2*c^2+3*b^4*c^2+3*b*c+3*b^2*c^4-5*b*c^3-5*b^3*c-b^3*c^3-4*d^2*b^2-4*d^2*c^2+8*a*d-8*a*d*b^2-8*a*d*c^2)/(-2*a*b*c*d+2*b*c+2*a*d-c^2-b^2+d^2)^(7/2)/(-d+2*a);



I get a final expression of

t72 = t32 + t57 / t65 / t63 / t62 / -d + 2 * a;
Could somebody send me a Maplet to solve systems of equations of any range ( linear,exponential , logarithm My e-mail is :
I am trying to calculate deflections of a beam (under their own weight) on multiple supports with a (nonsymmetric) overhang on either end. I've done the calculations by hand but would really like to write something in Maple to do it as I have alot of configurations to calculate. Can anyone help or give me some suggests? The way I have calculated the deflections involves calculating the reaction forces on the beam. Then calculating at general points along the beam. Integrating to give the bending moment M. Setting boundary conditions (such as M=0 at ends,M=M at supports etc). Then the deflection of the beam is given by y=(W/IE)*int(int(M)) subject to boundary conditions (y=0 at supports y'=y' at supports) where W=Load per unit mass, I=second moment of area E=Young's Modulus.
I would like to know how to tell Maple not to assume that two things commute, that is, AB != BA. I would like to be able to have maple expand expressions such as

(A+B)^2 = A^2 + AB + BA + B^2

instead of having it collect terms and ignore the multiplication order as it does when I use the "expand()" function.

Need to solve the following equation for real roots:
x^4 + 5*x^3 + 4*x = sin(x), with Digits:=6
it is giving me only one real root, but during the plot it shows two intersections suggesting two real roots. How can i overcome this problem?
What is the latest version of Maple 10 available? ( as in 10.x)
i am trying to solve: L_fire_7 := 0.5*trans_7 * p *((2 * h * c^2 / (lambda_7)^5) * (1 / (exp(h*c/(k*lambda_7*T)) -1))) = L7; L_fire_21 := 0.83*trans_21 * p *((2 * h * c^2 / (lambda_21)^5) * (1 / (exp(h*c/(k*lambda_21*T)) -1))) = L21; for T and p using PolynomialSystem. the result contains _X. i have no idea what that symbol means and can't find anything in the manual nor on the web. any help is highly appreciated! (also in regard to how to solve this better than using PolynomialSystem). -florian
I have written a relatively large simulation in Maple10 and it is literally taking forever to run for any decent size and time. I have been trying to convert to C to run in C, which became a serious problem, then I tried to use "compile" which again was very problematic. They seem to work only when the code is written in a C-like format anyway, in other words to use of lists and very fussy with arrays and procedures within procedures seems to create problems. I just wanted to ask if there is something clever I can do, to convert my procedure (there are about 20 of them) and if there is certain rigorous formatting I can do without having to literary re-write my whole code, as that is the way it seems now.
Hello , I have been trying to plot the solution to a boundary layer problem using Maple via the following programme: >BVP:={0.1*diff(y(x),[x$2]) + (x^0.5)*diff(y(x),x) - y(x) = 0, y(0)=0,y(1)=exp(2)}; >J:=dsolve(BVP,y(x), type=numeric,method=bvp[midrich]); >plots[odeplot](J,[x,y(x)], 0..1,color=blue,style=line,symbol=circle, symbolsize=12); However,before I can write the instructions to plot, I get an error message saying: "Error,(in dsolve/numeric,bvp) unable to achieve requested accuracy of 0.1e-5 with maximum 128 point mesh (was able to get 0.17e-4), consider increasing "maxmesh" or using larger "abserr" ."
I'm running Maple 10.02, Mac OS X.4.3, and Java 1.5, and when I give Maple an inverse laplace transform with a number, it returns the correct answer. But when I give it the same thing but replace the number with an arbitrary constant (i.e., I replaced 4 with k) it doesn't seem to be able to figure it out. Any suggestions on this?

> Maple Equation

I had been following a thread on comp.soft-sys.math.maple titled: Maple missing solutions?

In, short the OP was missing solutions to a set of equations involving sin and cos.

A respondent suggested converting to exp, which seems to have worked very well in that case.

For no particular reason I decided to try this with another equation and got some

results which I cannot explain. As follows:

> S1:=[solve(sin(x)=sin(1/x))];

A student of mine recently asked what algorithm Maple uses to calculate Eigenvalues. So, I tried diving into Maple Procedures. For example: >showstat(`Eigenvalues`); LinearAlgebra:-Eigenvalues := proc(A) .. [error catchers ommitted] .. 17 LinearAlgebra:-LA_Main:-Eigenvalues(`if` ... end proc How should I interpret that last line? Can I get Maple to show me what that procedure does? So far I've no luck cracking it. Also, is this the best/easiest way of going about learning what types of algorithms Maple uses. I understand that some (/many/all) of them may be proprietary and the persons at Waterloo may not want the general public knowing them, but even an answer as simple as "Accelerated Newton-Jacobi algorithm" would be good.
Hi, I have plotted the following chart using maple 10 on windows xp > plot(((x^2)+x-4)/(x-2),x=-4..6,y=-2..10); X being -4, 2 Which command needs to be executed to find the local extremity? Thanks in advance for any help… Robert
Another hour, another possible problem. Consider the following Maple statements:

> f := table([index=m]);
f := table([index = m])
> g := copy(eval(f));
g := table([index = m])
> g[index] := one;
g[index] := one
> h := g;
h := g
> f[index], h[index];
m, one
> g := copy(eval(h));
g := table([index = one])
> g[index] := two;
g[index] := two
> l := g;
l := g
> f[index], h[index], l[index];
m, two, two

So, after the first copy, the second table h has value one for index, while f still has value m for index. Yet, after the second copy, not only the third table l has value two for index, but also the second table h now has value two for index, while I have explicitly used copy to make a copy of h. Does this indicate a problem with the copy function?

a colleague just noticed the following (erroneous) behavior in Maple 10 :

> a := Psi(2, 2+2*I);
a := Psi(2, 2 + 2 I)
> printf("%+.6e\n", Re(a));
Error, (in fprintf) number expected for floating point format
> evalb(Im(a) <> 0);

The behavior is correct in Maple 9.5 :

> a := Psi(2, 2+2*I);
a := Psi(2, 2 + 2 I)
> printf("%+.6e\n", Re(a));
> evalb(Im(a) <> 0);

-- Regards,

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