bernie

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These are questions asked by bernie

Hello everyone

Here is my problem: I have a procedure depending on a variable and a parameter, let's say F(x,a). I have another procedure that gives me a specific value for x depending on the parameter a, let's say X1(a). I would like to make a list of values of F(X1(a),a) for different values of a. So the list would go F(X1(a1),a1), F(X1(a2),a2), and so on. Here is what I tried

xlist:=[seq(X1(i),i=1..10)]:

flist:=[seq(F(xlist,i),i=1..10)]:

but it doesn't work.

Another thing I tried was

Matrix([seq(eval(map(evalf@F(xlist,i),xlist),i=1..10)]):

Also doesn't work. Not with evalhf either. I can do it for specific values of xlist by choosing xlist[i] inside F, but that's it. If I leave i unspecified it can't do it.

 

Thanks for the help

 

 

Hi everyone

It's been a while since I last used Maple, so maybe these are simple questions

The first is:

I have a DE

eqbz:=diff(y(x),x)=-l/x^2*(y(x)^2-yeq(x)^2)

yeq(x) is a simple function of x and I want to solve it with "l" as a parameter and ic:=y(0.01)=1

sol:=dsolve({eqbz,ic},numeric,output=listprocedure,range=0.01..10^3,parameters=[l])

then I proceed to plot

ysol:=eval(y(x),sol)

ysol(parameters=[l=x]):

Hello

This is actually somewhat the same question I asked some months ago. I found a way to go around it, but now unfortunately I'm back to the same problem, and I didn't have any answers when I asked.

Here it is a system that I solve numerically:

##############################################

eq1 := diff(W(r), r) = -(1-beta*(W(r)-W0))*(M(r)+4*Pi*r^3*p(r))/(beta*r*(r-2*M(r)));

eq2 := diff(M(r), r) = 4*Pi*r^2*rho(r);

W0 := solve(thetaR = theta0-W0, W0);

Hello

I was trying to place the legend of a plot inside of it, and skimming through this site I found a solution based on a textplot, something like this:

plot(loglogplot1, loglogplot2, loglogplot3, loglogplot4): #just the functions to plot

textplot({[placement, 'typeset'(beta=10-9 ),color=black],[...],[...],[...]}): #just the value of beta changes

plot([placement],x=4..6,color=[black,blue,red,green],linestyle=[solid,dash,dot,dashdot]):

Hi

I browsed the forums but could not find a solution to my problem. Ii have a system of differential equations; however, I have the solution to one of the functions as an integral of another function in the system, but since the solutions are all numerical I don't know how to implement this. Here's the system and what I tried at first

#######################

eq1 := diff(W(r), r) = -(1-beta*(W(r)-W0))*(M(r)+4*Pi*r^3*p(r))/(beta*r*(r-2*M(r)));

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