MaplePrimes Questions

Hello,

I'm a very new beginner, and I have a question about getting the data of a curve from a JPG, without using manual measures an too getting more accurate datas.

I wish to fit the curve with a model. The JPG joined, from EU 2015, is about human thermoregulation. I still try to found a model with Mathematica but am uncertain seeing the result as illogic.

Did anyone write something to read curves from a JPG and get coordinates from these curves ? In the JPG, the curve is above, as an 'U'.

Thanks for your advice,

Milos.

Hello,

I've been trying to collect points at certain intervals in my plot, however, the sample option doesn't seem to be working. Can anyone lend me a hand? Any help is greatly appreciated! Thank you in advance!

Kind regards,

Gam

with(plots):

a := 1.501*10^9:

Th := sqrt(4*Pi^2*a^3/(G*(Mh+Msat))):

HyperionOrbit := proc (`θIC`, `ωIC`, n) local a, Mh, Msat, G, e, beta, M, Eqns, ICs, soln; global `ωH`, Th; a := 1.501*10^9; Mh := 5.5855*10^18; Msat := 5.6832*10^26; G := 6.67259/10^11; e := .232; beta := .89; M := Mh+Msat; Eqns := diff(theta(t), t) = omega(t), diff(omega(t), t) = -G*Msat*beta^2*(xH(t)*sin(theta(t))-yH(t)*cos(theta(t)))*(xH(t)*cos(theta(t))+yH(t)*sin(theta(t)))/(xH(t)^2+yH(t)^2)^2.5, diff(xH(t), t) = vxH(t), diff(vxH(t), t) = -G*M*xH(t)/(xH(t)^2+yH(t)^2)^(3/2), diff(yH(t), t) = vyH(t), diff(vyH(t), t) = -G*M*yH(t)/(xH(t)^2+yH(t)^2)^(3/2); ICs := xH(0) = a*(1+e), yH(0) = 0, vxH(0) = 0, vyH(0) = sqrt(G*M*(1-e)/(a*(1+e))), theta(0) = `θIC`, omega(0) = `ωIC`; soln := dsolve({Eqns, ICs}, numeric, maxfun = 0); plots:-odeplot(soln, [theta(t), omega(t)/`ωH`], 0 .. n*Th, numpoints = 2000, labels = ["θ(t)","ω(t)/ωH"], axes = boxed, style = point, sample = [seq(i, i = 0 .. n*Th, Th)]) end proc:

HyperionOrbit(.5, 1.8*`ωH`, 10)

Error, (in plot/options2d) unexpected option: sample = [0, 1876321.326, 3752642.652, 5628963.978, 7505285.304, 9381606.630, 11257927.96, 13134249.28, 15010570.61, 16886891.93, 18763213.26]

 

``

``

 

Download Poincare_section.mw

bia Man

Hello,

I have a matrix K.

K:=Matrix([<0, -1, 1, -1>,<-1, 0, -1, 1>,<-1, 1, 0,-1>,<1, -1, -1,0>]);

I would like to program this operation :

May you help me to code this operation?

Thanks a lot for your help

Hello,

I have an error in my code. I don't know where it came from. Earlier today I loaded this and it worked fine and now an error comes up. Any help is greatly appreciated! Thank you in advance!

Kind regards,

Gambia Man

with(plots):

``

HyperionOrbit := proc (`&theta;IC`, `&omega;IC`) local a, Mh, Msat, G, e, beta, M, Eqns, Th, ICs, soln, `&omega;H`; a := 1.501*10^9; Mh := 5.5855*10^18; Msat := 5.6832*10^26; G := 6.67259/10^11; e := .232; beta := .89; M := Mh+Msat; Eqns := diff(theta(t), t) = omega(t), diff(omega(t), t) = -G*Msat*beta^2*(xH(t)*sin(theta(t))-yH(t)*cos(theta(t)))*(xH(t)*cos(theta(t))+yH(t)*sin(theta(t)))/(xH(t)^2+yH(t)^2)^2.5, diff(xH(t), t) = vxH(t), diff(vxH(t), t) = -G*M*xH(t)/(xH(t)^2+yH(t)^2)^(3/2), diff(yH(t), t) = vyH(t), diff(vyH(t), t) = -G*M*yH(t)/(xH(t)^2+yH(t)^2)^(3/2); Th := sqrt(4*Pi^2*a^3/(G*(Mh+Msat))); `&omega;H` := 2*Pi/Th; ICs := xH(0) = a*(1+e), yH(0) = 0, vxH(0) = 0, vyH(0) = sqrt(G*M*(1-e)/(a*(1+e))), theta(0) = `&theta;IC`, omega(0) = `&omega;IC`; soln := dsolve({Eqns, ICs}, numeric); odeplot(soln, [theta(t), omega(t)/`&omega;H`], 0 .. 5*Th, numpoints = 2000, labels = ["&theta;(t)","&omega;(t)/&omega;H"], axes = boxed) end proc

HyperionOrbit(.5, 1.8*`&omega;H`)

Warning, The use of global variables in numerical ODE problems is deprecated, and will be removed in a future release. Use the 'parameters' argument instead (see ?dsolve,numeric,parameters)

 

Error, (in dsolve/numeric/SC/IVPpoints) unable to store '11.3097335529232/Th' when datatype=float[8]

 

``

``

``

 

Download Poincare_section.mw

Hello!

 

If I type this into a CAS calculator from Texas, I get the right result for Uc wich is 545.2.

solve(Uc&angle;-90=400&angle;X-150&angle;0+j*174.4,Uc,X)

This is used in AC circuits.

However, in Maple I'm using polar coordinates, so Im using this preamble:

phasor := proc (r, theta) options operator, arrow; r*cos(convert(theta*degrees, radians))+I*r*sin(convert(theta*degrees, radians)) end proc

This basically means that I can write phasor(value,angle in degrees) and get the lenth and angle of a vector on the complex plane.

Basically I want to know how I can make Maple solve this:

evalf(solve({phasor(U__C, -90) = phasor(400, X)-phasor(150, 0)+phasor(174.4, 90)}, {Uc, X})) Where I'm just interested in U_C , X doesn't matter.

I can't figure out how to do this with my current preamble. Does anyone know how to make this work?

Hi everyone,

 

Consider this maple 18 doc: Euler18.mw

 

The code is regular code for Julia sets of the exponential.

 

To see how the Julia set behaves at infinity, I apply the transform mu(z)=1/z.

 

The plot3d command correctly plots the Julia set at an appropriate neighborhood of infinity, but:

1) Axes are not transformed

2) Saving as .eps produces an empty plot, sans the axes (plot is saved correctly, when not applying mu(z))

 

Is there any trick to force the axes to also show correctly with the transformed ranges?

Seems that this misalignment is bothering the .eps renderer, which probably plots the graph in twilight zone, given the false ranges of the untransformed axes.

 

Any ideas on how to force the saveas .eps to work in this case?

 

Many thanks,

Yiannis

 

I once opened Tools-Tutors-Precalculus-Polynomials. Now every time I click the button of 'execute the entire worksheet', the same Tutor  window will pop up before Maple executes my codes. I wanna know how to prevent the window to pop up? 

Hello,

Now I'm doubting. Is this graph correct?

Hello,

I have an issue with this code. The issue lies in the warning which is outputed. However, I don't know how to resolve it. Any help would be greatly appreciated! Thank you in advance!

Kind regards,

Gambia Man

with(plots):

a := 1.501*10^9:

Eqns := diff(xH(t), t) = vxH(t), diff(vxH(t), t) = -G*(Mh+Msat)*xH(t)/(xH(t)^2+yH(t)^2)^(3/2), diff(yH(t), t) = vyH(t), diff(vyH, t) = -G*(Mh+Msat)*yH(t)/(xH(t)^2+yH(t)^2)^(3/2):

ICs := xH(0) = a*(1+e), yH(0) = 0, vxH(0) = 0, vyH(0) = sqrt(G*(Mh+Msat)*(1-e)/(a*(1+e))):

T := sqrt(4*Pi^2*a^3/(G*(Mh+Msat))):

soln := dsolve({Eqns, ICs}, numeric):

plots:-odeplot(soln, [xH(t)/a, yH(t)/a], 0 .. 10*T, scaling = constrained, labels = ["x/a", "y/a"], numpoints = 2000);

Warning, cannot evaluate the solution further right of 453574.15, probably a singularity

 

 

``

 

Download Hyperion_Orbit.mw

 

Hi

If I have this equation

and I need to use different Z, it's like

how can I solve it

Many Thanks

Amal

Hello,

I was wondering why there is difference in computer speed between two almost the same calculations.

Example:

61! + 1 costs 271 sec and 59! + 1 almost 0? Why is that? When there are small prime factors, the

calculation goes often faster, why? hanks in advance!

Dears,

I would like to draw a spectrum of plots. For example sin(mx) when m ∈ [1,2] and x ∈ [0,2] that is a spectrum of sinous plots. Obviously, if I write

plot(sin(m*x), m = 1 .. 2, x = 0 .. 2)

I will receive the error

Warning, expecting only range variable m in expression sin(m*x) to be plotted but found name x

I expect that there exist an alternative plot command in Maple, able to do that. I checked some members of Plots family that their name conducted me to check them. Moreover, I searched the web: but the most common retrieved results are related to drawing the area between two plots or under one plot.

A real example of what I am looking for is (not exaclty but something like) the below picure

A plot of Gaussian plots

Could you please let me know the alternative plot command, satisfying my requirement?

i am new on maple while usig maple i have to substitute a general value in an equation but could not do it like

> restart;
> taylor(f(x), x = gamma);

i typed this and want to replace x-gamma with e[n] which is easy and i did it but whn i want to substitute D(f)(gamma),(D@@2)(f)(gamma) and so on by (D@@k)(f)(gamma)=k!*c[k]*f(gamma) then i could not understand how can i do 2nd part 
pls help in this i m very thanlful to you

 

Hello!

I'd like to define a function after loading the Units package. But when using the defined function, Maple displays "Units:Standard-" everywhere. Even in labels of plots. I'd like to avoid that. A sample file is attached. Is there a better way of doing it?

Thanks.

 

Bruno

Test.mw

Hello, I am beginner with Maple 18, started recently, so I have some silly questions. I'm training the algebra study in Maple and got a list of exercises on the Internet, where they were asked to Prove it {5, 15, 25, 45, 55, 65} is a group with mod multiplication operation 90. If so, calculate the identity element and inverse of any element.

group.mw

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