Howdy,

I am trying to create a mathmatical model that shows a predator-prey relationship along with seasonal variations (hibernation). I made two piecewise functions where one is "on" during the winter and the other is "off" during the winter and the model worked well for one unit of time. 

My problem is that I would like the piecewise functions to apply over an arbitrary amount of time units periods without having to set the range within the function itself for 100 units of time. I was thinking that a for loop would work but i'm not sure how I would impliment that.

Thanks in advance!!

Edit: 

Here's a little bit more info on the problem.

I have three O.D.E's in an array..

ode := {r'(t),h'(t),c'(t)}

which are dependent on a list of parameters..

constants := {a,b,...,s,w,c0,h0,r0};

where s and w are my piecewise functions.

I am able to solve the three odes using dsolve for one period of s and w.

Again, I'm really not sure where to start to make my model periodic.

Why does "eval(c, [b=1,l=1])" turn out to be "1" not "1/1+x"??? its driving me cracy. THX

hey guys Im new client in maple and today I was about check out the resualt of my mathematic quastion with maple.

I need a step by step solution and exact command to give me true resualts 

for example 

how can I expand a factorization like (x^2-y^2) to (x-y)(x+y)

in a little more  complicated form (cd-1)^2-(c-d)^2/(d^2)(c-1)=5 the value of c=?

for solve this problem I need to expand (cd-1)^2-(c-d)^2 than other expands & in the end value of c

I dont have anymore time for my mathemathic exam so know that how maple works in basic and intermadiate mathematic level is important to me

thank you guys

When using more than 1 package is the following example (ecv3.mw) the best way?  It seems when I use more than 1 package without separating withstatements (using restart commands) my program doesn't work right.  What would be the best way to save the contents of all variables and lprint them at the end of program while preventing the restart commands from emptying variables which have been filled earlier in program execution. Thanks in advance! Les

Assume we have a map f from a polynomial ring R to another polynomial ring S, I know how to compute kernel (a generator for the kernel ideal) of these maps by Singular, but I want to know can I do it with Maple too? Thanks.

An example;

Consider the homomorphism f:k[x,y]-->k[u,v] sending x to v and y to v^2 then using Singular;

ring r1=0,(x,y),lp;

ring r2=0,(u,v),lp;

ideal i=v,v2;

map f=r1,i;

setring r1;

kernel(r2,f);

_[1]=x2-y

So at above I took k a field of characteristic zero. The kernel is the ideal generated by x^2-y.

What is the easiest way to ask roots of a polynomial on a finite field. For example asking roots of x^2+xy+y on GF(8)? I was thinking to run a two for on members of GF(8) and ask to check it but I couldn't do it using Galois package or maybe I couldn't use that package. Thanks for any help.

I am wondering why Maple does this.

> f:=x^2
> f(3)
output: x(3)^2

I understand the difference between an expression and a function. If f is an expression, shouldn't it ouput  x^2(3). Why is the output x(3)^2?

When I enter f*3 or f*(3) then I get the correct expression.

Here is a screenshot. http://prntscr.com/a7u9hm

Here is image inserted with a slightly different function

Also while I am here, what exactly does g(x):= x^2 do? when i enter g(3) I get g(3) back.

g(x) is neither a function nor an expression.

screenshot http://prntscr.com/a7ua75

Hello I'm having trouble create Konigsberg Graph on Maple. Here's the picture. Sorry if it's not clear enough. Thanks!

https://www.google.co.id/url?sa=i&source=images&cd=&ved=&url=https%3A%2F%2Fmvngu.wordpress.com%2F2011%2F03%2F26%2Fsimple-graphs-bridges-of-konigsberg-and-directed-graphs%2F&psig=AFQjCNFP-tdRTqi-VapOJZ-TLPdA1ndSgQ&ust=1456326114883065&rct=j

Hello Mapleprime

I have a complicated integration to solve that I can not find an analytical solution for or even a simplification. I thus defaulted to using a Riemann sum to evaluate it which works well but is slow. I have had great speed increase using quadrature methods before so thought to try this.

The general form of the integration is as follows:

int(int(f(a,b),a=0..10),b=1-a..1+a)

The integration domains are coupled which is causing the issue. a is independent but then b depends on a. The quadrature methods require the end points of integration to evaluate to a floating point number which the second integration cannot do. Is there any way to bypass this issue and use Quadrature methods?

Thank you in advance

As you can see on the picture, the numeric formatting is set to enginnering with 3 decimals, but it is now separated with a comma, so when I copy this answer to further calculate something, it will read it as a list, and it will give an error.

I have no Idea how this suddenly changed, its usually a period and there is no problem.

This is probably an asy fix, but I can't find any options for this.

Im running windows 10, and Im in Denmark.

Hello dears! Hope all you are fine. I am facing problem to integrate some expression please see the attachment and fix the problem. I am very thankful for your favour. 

Integration.mw

Mob #: 0086-13001903838

It returns unevaluated.  The solution is x=-ln(3),y=0.  In fact it doesn't give a solution even if the solution is provided as the initial point.  The value of Digits doesn't seem to make a difference.

(Tested Maple 2015.2 Macintosh and Maple 2015.1 Linux)

with(Student[LinearAlgebra]);
example1 := Matrix([[1, 2, 3], [4, 5, 6], [6, 7, 8]]);
whattype(example1);

testproc := proc (A) print(whattype(A)) end proc;

testproc(example1);

The whattype() calls output:

Matrix
proc() ... end proc

I don't understand why what is a Matrix type outside the procedure seems to change into this unrelated type? This is really bizarre. I feel like it may be something outside my code? Thank you.

the program is not recognized k

I have a set of differential equations on 3 variables, B[1],B[2] and C. Its not physically meaningful for B[1]+B[2]>0.5 so i would ideally like to replace the cube that the solutions are displayed on (the axis take the limits B[1]=0...0.5,B[2]=0...0.5,C=0...100 ) with a triangular prism (the axis take the limits B[1]=0...0.5,B[2]=0...0.5,B[1]+B[2]<0.5,C=0...100 ).

Failing that i'd like the plot to display a plane showing where the meaningful values for the variables end.

here is the code I use to put the ODEplot together

Model := [diff(B[1](t), t) = k[a1]*C(t)*(R-B[1](t)-B[2](t))-k[d1]*B[1](t), diff(B[2](t), t) = k[a2]*C(t)*(R-B[1](t)-B[2](t))-k[d2]*B[2](t), diff(C(t), t) = (-(k[a1]+k[a2])*C(t)*(R-B[1](t)-B[2](t))+k[d1]*B[1](t)+k[d2]*B[2](t)+k[m]*((I)(t)-C(t)))/h];
DissMod := subs((I)(t) = 0, Model);
AssMod := subs((I)(t) = C[T], Model);

Pars1a := [k[a1] = 6*10^(-4), k[d1] = 7*10^(-3), k[a2] = 6*10^(-4), k[d2] = (7/5)*10^(-3), R = .5, k[m] = 10^(-4), C[T] = 100, h = 10^(-6)];

Pars := Pars1a; thing11 := subs(Pars, AssMod[1]), subs(Pars, AssMod[2]); thing12 := diff(C(t), t) = piecewise(t <= 100, subs(Pars, rhs(AssMod[3])), subs(Pars, rhs(DissMod[3]))); sol := dsolve({thing11, thing12, C(0) = 0, B[1](0) = 0, B[2](0) = 0}, {C(t), B[1](t), B[2](t)}, numeric, output = listprocedure, maxstep = 2, maxfun = 1000000); ParsPlot1a := odeplot(sol, [B[1](t), B[2](t), C(t)], t = 0 .. 700, color = blue, view = [0 .. .5, 0 .. .5, 0 .. 100], tickmarks = [[0 = 0, .5 = R], [0 = 0, .5 = R], [0 = 0, 25 = (1/4)*C[T], 50 = (1/2)*C[T], 100 = C[T]]]);


But I can't see a way of either making the plane or making the ODEplot axis into something other than a cube.