Maple Questions and Posts

These are Posts and Questions associated with the product, Maple

I have Maple 14 on a macbook pro. I recently upgraded to the Yosemite operating system. 

 

I am trying to use the CurveFitting facility:

with(CurveFitting):

But I get nothing. This might be associated with Yosemite, or maple 14, or ????? Anyone have a guess?

In order to use efficient exponentiation modulo a number n, Maple help recommends using the inert &^ notation in the input, e.g. 5 &^ 1000 mod 29. But when I try to type this input in (default) 2D-Math mode, it interprets the ^ as it usually does for exponents and tries to "raise" the & to the power of 1000. Is there a way to do this correctly in 2D-Math, or do I constantly have to switch over to 1D-Math? I am using Maple 16. 

Hi,

I want to conduct the t- test with a

- null hypothesis of : M1-M2 >= 0

- alternative hypothesis of M1-M2 < 0

I found that I can choose the upper or lower tail option for the alternative hypothesis but I am not sure if the same as I want 

any idea ?

Thanks

Hello!

I'm trying to solve a differential equation of the form y.y"+y'+y= { 1 for 0<x<1 and 0 for else } with conditions: y(0)=0 and y'(0)=1.

I wrote this:

f(x):=heaviside(0)-heaviside(1);

Eq := y(x)*(diff(y(x), x, x))+diff(y(x), x)+y(x)-f(x);

ans := dsolve({Eq, y(0) = 0, (D(y))(0) = 1},numeric);

But it gives an error.

I also tried ODE tools>assistants>analyzer

It says: the ODE system does not contain derivatives of the unknown function heaviside.

 

It's the first time I use Maple and I don't know what to do. Need your help urgently. Thanks in advance.

 

Hi all,

I have an expression of the form Sum(a[l]*x^l,l=0..n).

Is there a shorter way to obtain let's say the 5 lowest orders than add(coeff(expression,x,l)*x^l,l=0..4) ?

 

Cheers

NOh

With your help I have a solution to a system of three equations:

(parameters are calculated on the basis of the data (for different values) - one example below)
A1=0.00002072968491, A2=0, A3=0.001946449287, A4=0.01946449287

B1=, B2=0, B3=0.0004773383613, B4=0.00004773383613

C1=, C2=0, C3=, C4=0.00009087604510

 

eqa1: = A1 * (diff (Tg (x), x, x)) + A2 * (diff (Tg (x), x)) + (A3 + A4) * tan (x) + A3 * Tg (x) + A4 * Tw (x) = 0;

eqa2: = B1 * (diff (Tw (x), x, x)) + B2 * (diff (Tw (x), x)) + (B3 + B4) * Tw (x) + B3 * Tg (x) + B4 * tan (x) = 0;

eqa3: = C1 * (diff (Tz (x), x, x)) + (C3 + C4) * Tg (x) + C3 * tan (x) + C4 * Tw (x) = 0;

 

indets ({eqa1, eqa2, eqa3}) minus {x};

res: = Dsolve (eval ({eqa1, eqa2, eqa3}) union {boundary conditions ??}, numeric);

 

for k from 0 to 20 evalf (res (k), 4); from;

c1:= 0.524:

c2:=0.05:

m: = 0;

for m from 0 to 20 and

T (m): = c1 * rhs (op (6, res (m))) + c2 * rhs (op (2, res (m))) + (1-c1-c2) * rhs (op (4, res (m))); print (m, T (m)); end to:

 

How and what type boundary conditions (I was thinking about the simplest or third type) to be able to determine the values on the y-axis on the graph. For example, the values started at -10, and ended at 10 (at a point (x, -10), (x, 10) in the coordinate system for a predetermined x, for example, from 0 to 20 which start at the point (0, -10 ) and stop at the point (20,10)). My main purpose is to collect these three solutions  to one equation T (x) = az * Tz (x) + and * Tw (x) + ag * Tg (x), and the ends of the graph, they should be in the above-mentioned points (0, -10 ) - start and (20,10) - stop.

 

Now thank you very much for the advice.

Ewa.

Hi,

I've noticed there are settings to set the type of index for spinors or gauge index in the physics package. i.e Setup(spinorindices=lowercaselatin). I also notice there is a setting for specifying the form of tetrads. 

I cannot find any further documention or examples on how to use these functions. Could anyone point me in the direction of a text or help function as to how these are implemented. 

Simple examples of things I am trying to do:

> with(Physics); Setup(spinorindices=lowercaselatin, metric = <some_line_element>)

> tetrad[`mu`,`~a`] = Matrix(<some tetrad matrix>) 

> Define(%)

I recieve the following error: invalid input: unknown uses a 2nd argument, a, which is missing.

I am hoping for a tensor that uses the metric to raise/lower the `mu` component and the minkowskian metric to raise/lower the `a` component. 

If there is further documentation that I am missing, I'm happy to check that out instead of asking lots of questions here. 

Thanks again.



This is my code for the Extended Euclidean Algorthim which should return integer l, polynomials pi,ri,si,ti for 0<=i<=l+1. And polynomial qi for 1<=i<=l such that si(f)+ti(g) = ri and sl(f)+tl(g)=rl=GCD(f,g).
The problem is, I keep getting division by zero. Also it evaluates pi = lcoeff(ri-1 - qiri) to be zero, everytime. Even when I remove this it still says there is a division of zero, which must be coming from qi:=quo(ri-1,ri, x); however I do not know why considering the requirements for the loop are that r[i] not equal zero. I really could use a fresh pair of eyes to see what I've done wrong. Any help would be greatly appreciated!!

Hi there,

Is there a way in which i can solve the following optimal control problem numerically with Maple?

 dH/dt=λ-µ H-(1-u1)β H V+δ I,

dI/dt=(1-u1)β H V-σ I,

‎dV/dt=(1-u2)k I-γ‎V,

dλ1/dt=-1+λ1µ+β‎‎V(1-u1)(λ1-λ2),‎

dλ2/dt=λ1δ+λ2σ-λ3(1-u2)k‎,‎

‎dλ3/dt=β H(λ1-λ2)(1-u1)‎‎+λ3γ.

where

u1=βHV(λ1-λ2)/A1,

u2=-λ3kI/A2,

σ = α + δ,

and

H(0)=1.7*10^8,    I(0)=0,    V(0)=400.

 

λ=5*10^5,    µ=0.003,     β=4*10^(-10),    α=0.043,    δ= 0.2                  k=6.24,       γ‎=0.65.

A1=900, A2=1000.

 

Answers and advice are very appreciated. 

Thank you all for reading.

Aylin

Hello, I'd like to use Maple to use Newton's Method in an interval to find multiple roots of 4xcos(3x)+(x-2)^2-2=0. What I have so far is:

with(Student[NumericalAnalysis]):
f := 4*x*cos(3*x)+(x-2)^2-2:
Newton(f,x=2,tolerance=10^(-4));

 

Other than trying out different initial guesses is there a way to do this?

Hi everyone!

I wrote simple program which fits experimental result. I know that experimental points should be fitted with this function — Te=exp(a*X+b), where "a" and "b" are parameters. "X" — vector of independent variable, "Te" — vector of dependent variable.

My question is: can maple estimate error of my fitting? I want to obtain "a±Δa" and "b±Δb".

My program: Profile.mw

P.S. Excuse me, for my english. It isn't my native language.

I got a problem with a difficult ode,the commands are below.

restart;
sys := 1.*(diff(x(t), t, t)) = piecewise(b(t) = 1, 0, 1003.0-1000.*x(t)-30.*(diff(x(t), t))-25.*signum(diff(x(t), t)-.1)-.3*signum(diff(x(t), t))*exp(-2*abs(diff(x(t), t)))), x(0) = 1, (D(x))(0) = 0;
mu := 100;
stick := [diff(x(t), t) = .1, b(t) = piecewise((1000.-1000.*x(t))^2 < 10000, 1, 0)];
slip := [[0, 10000 < (1000.-1000.*x(t))^2], b(t) = 0];
sol:=dsolve({sys,b(0)=0},numeric,discrete_variables=[b(t)::float],events=[stick,slip],event_maxiter=1000000,output=listprocedure,maxfun=0,range=0..8);

any advice is appreciated.

In Maple 16  (obviously, the result must be positive):

VectorCalculus:-int(x+y, [x, y] = Sector(Ellipse((1/4)*x^2+(1/9)*y^2-1), 0, (1/2)*Pi));

                                                                        -2

Probably, this error occurs only in the latest versions, as in Maple 12 the output is correct. It would be interesting to know the reason for this behavior.

 

I have to calculate the data in JSON format and export the result back to JSON.

It would be greate if there is any JSON package for Maple.
---

Also, I use`ExportMatrix` to export the result to CSV format.

But there are some comma (`,`) in the result content and `ExportMatrix` does not handle it well.
Is there any solution for export data to CSV file in my situation?

Thanks.

 

First 1303 1304 1305 1306 1307 1308 1309 Last Page 1305 of 2223