hello i have the following set of ode's:

ode_sub := diff(S(t), t) = -k1*S(t)-S(t)/T1_s;
ode_P1 := diff(P1(t), t) = k1*S(t)-k2*(P1(t)-P2(t)/keq)-P1(t)/T1_p1;
ode_P2 := diff(P2(t), t) = -k2*(-keq*P1(t)+P2(t))/keq-k4*P2(t)-P2(t)/T1_p2;
ode_P2e := diff(P2_e(t), t) = k4*P2(t)-P2_e(t)/T1_p2_e;

ode_system := ode_sub, ode_P1, ode_P2, ode_P2e;

with these parameters:
s0 := 10000;
k2 := 1000; T1_s := 14; T1_p2_e := 35; T1_p2 := T1_p1;
 

i want to find the unkown parameters : T1_p1, k1, keq and k4

my idea was this:

init:=S(0)=s0,P1(0)=0,P2(0)=0,P2_e(0)=0

dsolve({ode_system,init})

sol := combine(expand(%));
PS := subs(sol, [S(t), P1(t), P2(t), P2_e(t)]);
 

P1fu := unapply(PS[2],t);
Sfu := unapply(PS[1],t);
P2fu := unapply(PS[3],t);
P2e_fu := unapply(PS[4],t);
P2_total := unapply(P2fu+P2e_fu, t);
 

the following data is given:

T:=<0,2,4,6,8>

S:=<9999.99913146527,8328.870587730016,6937.009129218748,5777.745632133724,4812.209983843559>

P1:=<0.0,67.86790056712294,114.88787098501874,145.95438088662502,164.85650644237887>

P2_P2e:=<0.0,271.68492651947497,461.9130396605823,589.3710176125417,668.9967533337124> # data from P2(t)+P2_e(t)

making the rediduals:

RP1 := convert(P1-P1fu~(T), list);
RS := convert(S-Sfu~(T), list);
RP2_P2e := convert(P2_P2_e-P2_total~(T), list);
 

RPs := [op(RS), op(RP2_P2_e), op(RP1)]

res := Optimization:-LSSolve(RPs, k1 = 0 .. 1, keq = 0 .. 10, k4 = 0 .. 1, T1_p1 = 0 .. 100)

i dont know wheter or not the last step work to get the parameters becuase it takes to long to compute. is there a smarter way to obtain the parameters of the ode's? a numeric approch ?

i tried with dsolve({ode_sysytem,init},numeric,'parameters'=[k1,keq,k4,T1_p1]) however it doesnt seem to get my anywhere since i need to know the parameters to use this (i think)

hope someone can help:)

Hello everyone,

I am making a mobile robot simulation in the MapleSim environment and I need to create varriable (uneven) terrain, do I need an additional library for that?

If not how can I do so?

Thanks for your time!

John

how to convert a^2*b+c to func2(func1(func1(abc[1],abc[1]),abc[2]),abc[3])

when i use custom function func2 to represent plus, func1 to represent multiply

input 3 parameters,

one is a^2*b + c one is [func1, func2] and second is [abc[1],abc[2],abc[3]] corresponding to a, b, c
a^2*b + c = func2(func1(func1(abc[1],abc[1]),abc[2]),abc[3]);

This is simplified from a larger example.  I never saw Maple exit from a numercal calculation.

> 123456789 ^ 987654321:
Execution stopped: Stack limit reached.

Process Maple R2016 exited abnormally with code 158

> kernelopts(maxdigits);
                                  38654705646

> lprint(123456789. ^ 987654321.);
.4339566080e7991619731

kernelopts(memusage) shows about 2~3 meg bytes used.

The system has 16G Ram.  16G swap.

Seems like something maple should have caught.

I need help to create a program that will find all the positive integers n, where n < 1000, such that
(n 􏰀-1)!= 􏰁 􏰀-1 (mod n^2 ) . program has to be in full and state the values of n obtained. 

Try solve 

restart; with(PDEtools);
U := diff_table(u(x, y, z));

pde[1] := x*y*U[z]+x*U[x]+2*y*U[y] = 0;

bc[1] := eval(U[], z = 0) = x^2+y^2;
sys[1] := [pde[1], bc[1]];
pdsolve(sys[1])

Maple nothing returned. Where my mistake ?? Thank you.

Hi

We solve the following ode in the interval (0,Pi):

 diff(u(x),x,x)+u(x)=f(x);

bcs=u(0)=0, u(Pi)=0;

Stating one example of many conditions for such equation to have a
valid solution

Many thanks

restart;
eq1 := T - M*g = 0;
eq2 := T1*sin(theta1) + T2*sin(theta2) - T = 0;
eq3 := -T1*cos(theta1) + T2*cos(theta2) = 0;
soln := solve({eq1,eq2,eq3},{T,T1,T2});

limit(subs(theta2=theta1,soln[3]),theta1=0);

This returns a limit -> ... expression.  Since there is a sin(theta1) in the denominator, this should be undefined or infinity.

I am tryng to change variables in multiple integral as below, but receive error. Help me to do so.
 

Download inttt.mw

I don't know where to ask this.  Sorry if this is the wrong forum.

I use maplev-mode

;; Version:    2.155
;; X-RCS:      $Id: maplev.el,v 1.14 2006-06-02 14:02:38 joe Exp $
 

I am attempting to modify it so
  f1 invokes maplev-cmaple-send-line
  f2 invokes maplev-cmaple-send-region
  f3 invokes maplev-cmaple-send-buffer
 

tried adding
(define-key map [(control c) (control c) ?l] 'maplev-cmaple-send-line)
(define-key map [(f1)]  'maplev-cmaple-send-line)

but, emacs seems to not recognize this.  I can change the global keymap to get this behavior.
Is there a way to do this in maplev.el?
 

Tom Dean

Hey everyone!

My question is pretty straightforward: I have a second degree tensor and I need a fourth degree order one from it.

In Python, there is a command that performs the action, would there be one in Maple? Or any kind of process to go through to get the result?

Thanks

My code :

> restart; with*PDEtools;

> PDE := diff(u(x, t), `$`(t, 2)) = 4*(diff(u(x, t), `$`(x, 2)));

> pdsolve({PDE, u(x, 0) = cos((1/2)*x), (D[1](u))(x, 0) = 0}, u(x, t));
 

And i get Error, (in pdsolve/BC) invalid input: indets expects 1 or 2 arguments, but received 3.Please help me find my Error.Thank you!!!

I would like to see the list of metrics recognize by Maple with their acornym.  For example,:

>Setup(coordinates = spherical, metric = kerr)

What can i do in this case? I,m traying solve a system of non linear equation like this, i want to know Rs and Rsh:

Dear friends

I have a long-running code that sometimes takes an hour to complete. I wonder is there a way to find out what line of code is currently running in a long-running maple code or to show an update of the variables. I have some print commands but are shown just after completion not before. 

Thank you in advance for your time.