Maple 15 Questions and Posts Maple 15 Questions and Posts Feed

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1.

   Suppose thT the population y(t) of a certain kind of fish is given by (D(y))(t) = Ay(t)-By(t)^2, and fish are caught at a rate Hy proportional to y.Solve this so-called schaefer model. Find the euilibrium solutions y1,y2(>0) when H

2.< Intermittent harvesting>

 In 1. assume that you fish for 3 years, then fishing is banned for the next 3 years. Thereafter you start again. And so on. This is called intermittent harvesting....

1. x^2*diff(y(x),x,x)+x*diff(y(x),x)+(x^2-1/9)*y(x)=0

I want solve this equation with Bessel'function in maple.

 

2. x*(diff(y(x),x&2))+2*(diff(y(x), x))+16*x*y(x) = 0

3. x*(diff(y(x),x&2))+(2*x+1)*(diff(y(x), x))+(x+1)*y(x) = 0

I want solve these equation with frobenius method in maple.

 

Thank you ♥

I want to get result like this:[0.003,123], however, it turns out to be like this: 

Good curve fitting II...

September 03 2013 Jimmy 10

Hi,@Carl Love sorry for my crosspost, I miss click. I try to reply under your response, but it does not show my reply under your response.

Thank you very much, you solve my problem, the method you provided is useful.

But now another formula need to be fit, previously, I use Excel to do the best_answer_optimization, I want to know if Maple could do it. The formula is as follow ...

Hi, I want to substitute the result from NonlinearFit into formula and plot together with raw data.

I have two files v.txt and i.txt , v stands for voltage, i stands for current, using formulato fit my raw data,

The picture is captured from my screen.

Hi, I want to substitute the result from NonlinearFit into formula and plot together with raw data.

I have two files v.txt and i.txt , v stands for voltage, i stands for current,  using formula  to  fit my raw data, 

Let $F, f_1, \ldots f_5$ be polynomials in $\mathbb{Z}_p[r,s,t,u,v]$, the ring of polynomials in 5 variables over the integers modulo an odd prime $p$. By forming the ideal $J:=<>$ I can test whether $F$ is a member of $J$. Indeed $F$ is a member of $J$ and so I know there exists polynomials $a_1,\dots,a_r \in \mathbb{Z}_p[r,s,t,u,v]$ such that $$F = a_1f_1+\dots+ a_rf_r $$ My question is how to explicitly compute $a_1,\dots,a_r$ in Maple, or Sage if you prefer. Thank...

A better Numerical solve...

August 23 2013 fox49 5

Hello,

I'm rediscovering maple, and i want to find the zeroes of an expression by numerical calculation. But it seems that the function fsolve can not handle the monster i created...

(The monster in question here is a determinant of a 12x12 matrix with one variable an trigonometric functions that i don't want to copy pas (NDA))

The problem might comes from the extrem values it gives for a numerical calculation (slope around 1e6)...

 

what is the difference between using DEtools forexample bernoullisol and dsolve directly?

I have been solved a optimization problem by

When defining a polynomial as follows

p:=x->x^(r+1)-(r+1)*Sum((-1)^(r+k)*(r+k)!*(r+1)!*r!/((k!)^2*(r-k+1)!*(2*r+1)!)*x^k,k=0..r);

the result of

simplify((eval(p(1),r=1)));

is given as 1 whereas hand evaluation and also plotting the polynomial clearly shows that the result is 0. How can this behaviour be explained?

with(PIR):
RPP:='PIR/homalg';

'homalg/default':=RPP;

Error, illegal use of an object as a name


var:=[I];PIR['Pvar'](var);

test1 := (3*f-f^2)*(Diff(g, x))+(-f+3*f^2-2)*(Diff(g, y))+(2-f^2)*(Diff(g, z));

test1r := solve(test1=0,f);

 

how to solve this in terms of Diff(g,x), Diff(g,y) etc.

after solve, it is like a bug, because result is Diff(1,x) etc where is g?

 

How can I install package "gravitational" for system Win7 (maple 15 and maple16)?

Hi,

I am trying to define a system of units so that I get results in the units I want.

Specifically; I want to use energy in MeV (or eV, if I have to) and masses*c^2 in MeV (or eV) as well. Related, I need ScientificConstants like Planck's h in MeVs etc.

So I say

AddSystem('Accelerator','MeV','meter','second');
UseSystem('Accelerator');

which is accepted. I even get energies converted to MeV if I enter one in a different unit and use

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