# Maple 15 Questions and PostsMaple 15 Questions and Posts Feed

These are Posts and Questions associated with the product, Maple 15

### Good curve fitting II...

September 03 2013
0 5

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 ...

### substitute the result of NonlinearFit into formula...

September 02 2013
1 1

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.

### substitute the result of NonlinearFit into formula...

September 02 2013
0 0

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,

### How to write standard decomposition of a polynomia...

August 31 2013
2 1

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
1 7

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 forex...

August 22 2013
1 4

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

### optimization problem...

August 16 2013
1 7

I have been solved a optimization problem by

### Why does simplify produce wrong results for this p...

August 12 2013
1 2

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?

### Error, illegal use of an object as a name...

August 10 2013
0 2

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

'homalg/default':=RPP;

Error, illegal use of an object as a name

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

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

August 10 2013
1 2

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 syst...

August 09 2013
1 7

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

### How to define a new system of units?...

August 05 2013
0 4

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

UseSystem('Accelerator');

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

### How do I graph a solution curve in the phase plane...

August 01 2013
1 1

I am dealing with second order linear differeantial equations for RLC and forced RLC circiuts.

I am having trouble with plotting a solution curve in the phase plane.

> restart;

with(plots); with(DEtools);

L := 10; R := 20; C := 1/100;

de1 := diff(x(t), t) = y(t);

de2 := L*(diff(y(t), t))+R*y(t)+x(t)/C = 0;

DEplot({de1, de2}, [x(t), y(t)], t = 0 .. 5, [[x(0) = 10, y(0) = 0]], stepsize = 0.5,

### Warning, solution may have been lost...

July 18 2013
2 4

Hi,

I have a problem solving two equations with trigonometric functions. They are as follows:

eq1:= 9180pi - 16295.070arccos(-1.0 + 0.001356852103xu) + 22.1100sin(-1.0pi + 1.0arccos(-1.0 + 0.001356852103xu))(737.0-xu)+7115.0700arccos(-1.513347022 + 0.002053388090xu) - 14.6100sin(-1.0pi + 1.0arccos(-1.513347022 + 0.002053388090xu))(737.0-xu) + (0.1050As(xu-125)/(1349-xu)) - 0.1050As = 1688

eq2:= 9180pi- 16295.070arccos(-1.0 + 0.001356852103xu) + 22.1100sin...

### Numeric Integration...

July 14 2013
1 9

I ran into an interesting situation with numeric integration.

For a simulation task I need to evaluate an overlap integral of a pair of 3-d ellipsoids which have a certain aspect ratio and the axes of which are tilted against each other. The distribution in each plane is Gaussian, but with largely differing sizes. While I have an analytic expression for the result; the integration (along a certain direction) cannot be done analytically and so I integrate numerically....

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