Hi

I wrote a custom recursive procedure to calculate some value (it is an implementation of a recursive algorithm)
During the further calculations derivatives of this procedure occur. Because of the statements in the specific procedure the automatic diff of a procedure does not work (at least I think that is the reason). However this is no problem as the differentiation is far from simple. L'hopitals rule needs to be used when necessary and Maple cannot detect when it needs to be used automatically (because there is another function, implicitly defined involved).
Therefore I am looking to write my own diff procedure as an extension. From the manual I gathered that this can be done as such `diff/name_of_type' =... however my procedure is not a type and I cannot easily write a 'type/name_of_type' function to define it as such. Can someone help me out?

I've made a toy example:

toy_example.mw

I know that in the case of this toy example other ways are possible.
What I need is a way to write my own procedure to evaluate the differential (D[1](A))(1,2,3);

Possibly defining procedure A as a type and writing 'diff/A'=proc...

Thanks

Hello,

I have a two variable function d(a,b) which i don't want to substitute for the result. How can I make this product distributive,e.g. d(a+b,c)=d(a,c)+d(b,c) with independece of the variables I introduce in the function?

Thank you for the help!

EF.3.mwHi, I want to ask that how to find the exact solution of equation without applying any technique

Hi all,

I had to do a clean install on my computer today. When I went to reinstall Maple, I got a message telling me that my download link wasn't valid. So I tried to get a new download link, but that didn't work either. Does anyone know if I will still be able to download the software without purchasing the latest version? I'm pretty sure my license has not expired.

I'm going to call support tomorrow morning, but I figured I'd ask around here in the meantime. Thanks!

Hello.

When I input an expression such as 3*(2*x-1)(x+1) > 0 into a Maple worksheet, Maple outputs this:

0 < 6*x(x+1)-3

(sorry, the formatter doesn't work for some reason).

I was wondering by which rules Maple determines to output that instead of, for example,

0 < 3(2*x^2+x-1)

or

0 < 6*x^2+3x-3

Also, Maple can't seem to be able to solve the inequality. It gives the following error to the command:

solve( { 3*(2*x-1)(1+x) > 0 } );

Error, (in solve) cannot solve for an unknown function with other operations in its arguments

So, I was wondering, is there a way to force Maple to output either in the most factorized form (which should be what I gave it as input) or in the least factorized form (that is, multiply it all)?

And, of course, why can't I solve the inequality with Maple?

Im working on a assignment on maple. I have an equation of motion that looks like this:  v(t):= -g*t-vs*ln(r*t-m)+vs*ln(-m)
Im supposed to use this equation and solve it for t an later integrate it. Since the constant inside the ln is negative I end up with a annoying imaginary part. Is there any way to covert this equation so that the ln disappear, so that I can get a result whitout a imaginary part?

sys := [(diff(c(t), t))*(diff(a(t), t))*(diff(b(t), t))+(diff(c(t), t))*t^2, (diff(c(t), t))*(diff(a(t), t))*t+(diff(c(t), t))*t*(diff(b(t), t)), (diff(c(t), t))*(diff(a(t), t))*(diff(b(t), t))+(diff(c(t), t))*(diff(a(t), t))*t+(diff(c(t), t))*t^2]
DEplot(sys, [a(t), b(t), c(t)], t = 0 .. 2, a = -15 .. 15, b = -15 .. 15, c = -15 .. 15, color = magnitude, title = `Stable Limit Cycles`, arrows = curve, dirfield = 800, axes = none);
odeplot(sys, [t, a(t), b(t), c(t)], -4 .. 4, color = orange);

mysolve.mw

Download mysolve.mw

with(RegularChains);
with(ConstructibleSetTools);
source1 := PolynomialRing([a, b, c, d]);
target1 := PolynomialRing([e1, e2, e3, e4]);
source1list := [eq2a, eq3a, eq4a, 0];
target1list := [eq2b, eq3b, eq4b, eq5b];
cs := PolynomialMapPreimage(target1list, source1list, source1, target1)

return
cs := constructible_set

then i type
Elements(constructible_set)

it return 

Elements(constructible_set)

 since source has less number of variables, in order to use this function

i add a dummy variable d to this and use 0 for the fourth equation

hello all

i have two equations

(1-pi*x/2)*(f/2/E)*yc-1/3=int(t^4/sqrt((t^2-(f/2/E)*yc)^2+ya^2),t=0..1);

x^2*yc*(1-pi*x/2)-1/3=int(t^4/sqrt((t^2-x^2*yc)^2+ya^2),t=0..1);

i want to plot ya and yc vs. x that x change beetwin -3..3 in some steps like 100 steps. and another members like E can be any number.

i think maby i shoud use loop! but i dont know how!

plz help me

Hi,

I want to plot two density functions of norm(1,1) and norm(4,1) in one figure.

But it appears the function DensityPlot can only plot one at a time.

The downloaded worksheet below displays 3 points on the unit sphere which define a solid angle with a triangular face. The sides of the solid angle's are red arcs on the surface of the sphere and red radii which outline the planar sides within the sphere.

Three questions:

1. Is there a way to make the surfaces of the solid triangle more apparent by filling them with color?

2. Is there a way to calculate the area of the face on the surface of the sphere?

3. Is there a way to calculate the volume of the solid triangle?

Download Mechanics;_irregular_solid_angle.mw

I am trying to solve system of partial differential equation, but i got some trouble. This is system of heat equations

Here are the equations:

restart;with(PDEtools):
U1 := diff_table(u1(x,t)):
pde[1] := (1/kappa1)*U1[t]=U1[x,x];

bc[1]:=u1(-L, t)=V;

U2 := diff_table(u2(x,t)):
pde[2] := (1/kappa2)*U2[t]=U2[x,x];

bc[2]:=u2(a, t)=0;

sys:=[pde[1],bc[1],pde[2],bc[2], u1(x=0,t)=u2(x=0,t), 

D[2](u1)(x,0)=D[2](u2)(x,0)

]

pdsolve(sys);

a and L is arbitrary constanta

anyone can help? The last boundary conditions I mean du1/dx=du2/dx at x=0

How can i solve this problem? 

So given a list [ [ [1,2], [2,1] ], [ [3,4], [4,3] ], [ [5] ] ],

I would like to produce a list 

[ [1,2,3,4,5], [1,2,4,3,5], [2,1,3,4,5], [2,1,4,3,5] ]

so it makes a combination of sublist of every lists in the given list

is there a way to do it ?

Thanks,