Maple 2017 Questions and Posts

These are Posts and Questions associated with the product, Maple 2017

Hello everyone,

I am trying to solve an equation using the "solve(...)" function but the coefficients of the equation are changing.

I am using the coefficients as list but the "solve(...)" function gives error: "Error, (in assuming) when calling 'Engine:-Dispatch'. Received: 'badly formed input to solve: not fully algebraic'"

I am attaching the Maple document.

 

However, what I want to achieve, is the solution for each value in the list.

Here is an easy example of what I am saying:

a=3*x+k where k=[list of values], a=[another list of values].

I want to find "x" for each pair of values (a,k) in the list.

 

Thank you !
 

``

``

LCC Resonant Converter - Frequency Finder

 

 

restart``

with(Student[Calculus1])

V__out := 50.0

`ω__line` := 2.0*Pi*50

t := [seq(0 .. 10*10^(-3), .1*10^(-3))]

theta := `ω__line`*t

v__line := 85*sqrt(2.0)*`~`[sin](theta)

m := 1

Q__s := 3.2*`~`[`^`](`~`[sin](theta), 2)

``

f__n := `assuming`([solve((1/120)*V__out = 1/sqrt((-m*x^2+m+1)^2+(Q__s*(x-1/x))^2), x, useassumptions)], [x::positive])

Error, (in assuming) when calling 'Engine:-Dispatch'. Received: 'badly formed input to solve: not fully algebraic'

 

``


 

Download LCC_gain_freqFinder.mwLCC_gain_freqFinder.mw

H all expert

first this Expression 

ni := diff(Q(x, t), t)+a*Q*(x, t)*(diff(Q(x, t), x))+b*(diff(Q(x, t), t$3))+d*(diff(Q(x, t), t$5)) = 0

then I want to solve  diff(Q(x, t), t$5) 

diff(Q(x, t), t$5) = solve(ni, diff(Q(x, t), t$5))#eq2

p (x, t) :=H1(t)*Q(x*H2(t), H3(t)) #assumption 

k := diff(p(x, t), t)+a*p(x, t)*(diff(p(x, t), x))+diff(p(x, t), t$3)+d*(diff(p(x, t), t$5))+c*p(x, t) #eq3

r := subs(diff(Q(x, t), t$5), k) #subs eq2 in eq3

i recived error

SUBS1.mw

Hi,

I have a code (see below) for the following number sequence and want to produce a graph as well as the numerical data, please advise how to do it.

Sequence definition: Lexicographicaly least sequence of nonnegative integers commencing 1,3,5,7 such that any four  consecutive terms are mutually coprime.

The code I have so far is: 

ina := proc (n) false end :

a := proc (n) option remember; local k;

if n < 5 then k := 2*n-1

else for k from 2 while ina(k) or igcd(k, a(n-1)) <> 1 or igcd(k, a(n-2)) <> 1 or igcd(k, a(n-3)) <> 1

do  od 

fi; ina(k) := true; k

end proc;

seq(a(n), n = 1 .. 100);
1, 3, 5, 7, 2, 9, 11, 13, 4, 15, 17, 19, 8, 21, 23, 25, 16, 27, 

  29, 31, 10, 33, 37, 41, 14, 39, 43, 47, 20, 49, 51, 53, 22, 35, 

  57, 59, 26, 55, 61, 63, 32, 65, 67, 69, 28, 71, 73, 45, 34, 77, 

  79, 75, 38, 83, 89, 81, 40, 91, 97, 87, 44, 85, 101, 93, 46, 

  95, 103, 99, 52, 107, 109, 105, 58, 113, 121, 111, 50, 119, 

  127, 117, 62, 115, 131, 123, 56, 125, 137, 129, 64, 133, 139, 

  135, 68, 143, 149, 141, 70, 151, 157, 153

I have tried listplot but for some reason cant get the correct format

Hope you can help

Best regards

David.

Hi, I'm trying to solve auxilary equation to find its familes but I don't know what I'm doing wrong as I'm using following code:

famtemp := (diff(z(xi), xi))^2-a*z(xi)^2-b*z(xi)^3-c*z(xi)^4;

fam1 := simplify(`assuming`([dsolve(famtemp)], [b::real, a::real, c::real, -4*a*c+b^2 > 0, a > 0]))

I want to get the following family:

fam1 := 2*a*sech(sqrt(a)*xi)/(sqrt(-4*a*c+b^2)-b*sech(sqrt(a)*xi));

I hope someone will help me to solve it.

Thanks

Given  3000 linear equations in 3000 unknowns, with coefficients in a field of rationals with one algebraic number extension, which Maple solver would be fastest in solving the system?

have table like table(symmetric, [() = x]) from other code not mine, strange syntax

how to extract x from table thanks

I have an array with a list of parameters. Suppose there are three parameters, t1, t2 and t3. I like to evaulate the array for different values of the parameters. I can do it manually by a command such as

eval(array, {t1=1, t2=5, t3=10})

What is a more systematic approach and how can it be done? Suppose I do not know the number of paramters in advance and the number of parameters could possible be large. Once I know the number of parameters, I would like to map a list of values to the parameters.

Thanks in advance!

with(GroupTheory):
MinimumPermutationRepresentationDegree(PermutationGroup({[[2, 3], [4, 5]], [[2, 5], [3, 4]]}, degree = 5, supergroup = PermutationGroup({[[2, 3, 4]], [[1, 2], [4, 5]]}, degree = 5)));

#an error appears in Maple 2017
 

How does Maple interpret the second line to get that result ??

I had to put expicitly a dot between the brackets to fix it.

 

Kind regards, Detlef Hoyer

ff := dsolve({eq1, Vt(0)=0}, Vt(t), type=numeric, method=classical, start=0, stepsize=.00001);

this is a old syntax of maple 5, with maple 2017 version it is not working, is it possible to solve non linear equatins with maple

When trying to understand what a proof is trying to show, I like to construct some examples to see what the proof is trying to show. For example, constructing some sequence to show whether it converges, visualizing some functions to understand the squeeze theorem in calculus, etc. I found Maple has worked well for this kind of work.

Now I am taking course in Measure Theory and everything is so abstract and I am not sure if Maple is capable of building the objects discussed. For example, this is from the book Probability Essentials:

How can I use Maple to support understanding the proofs? It would be nice if I can build the objects discussed and write functions to verify their properties and just play around with them in general to get an intuition of how the proof works.

 

 

 

 

Requesting a code to compute (and graph) the following self referencing sequence:

a(1)=1. If a(n) is a novel term (seen for the first time) then a(n+1)= d(a(n)) where d(k) is the number of divisors of k. 
if a(n) has been seen before then a(n+1) = a(n)+m where m is the least prior term which has not already been used in this way (once m is used it cannot be used again).

Sequence starts:

1,1,2,2,3,2,4,3,5,2,4,6,4,7,2,5,7,11,2...,

note that there are often multiple copies of the least unused term, which might make accounting for them tricky. 

Thanks in advance 

 

 

Can anyone please help with this?  I don't know what is the problem in this code.

 

restart; _EnvExplicit := true; with(DEtools); with(PDEtools); with(plots)

true

(1)

NULL

Check*the*constraint

eq1 := diff(X(z), z, z)+((diff(H(z), z))/H(z)-2/(1+z))*(diff(X(z), z))+exp(-sqrt(2/3)*X(z))*ZETA*(diff(Y(z), z))^2/(2*sqrt(6))-Y(z)*exp(-sqrt(2/3)*X(z))*(1-exp(-sqrt(2/3)*X(z)))/(2*H(z)^2*sqrt(6)*(1+z)^2) = 0

eq2 := diff(Y(z), z, z)+((diff(H(z), z))/H(z)-2/(1+z))*(diff(Y(z), z))-(1/3)*sqrt(6)*(diff(X(z), z))*(diff(Y(z), z))+(1-(1/2)*exp(-sqrt(2/3)*X(z)))/(2*ZETA*H(z)^2*(1+z)^2) = 0

eq3 := -2*H(z)*(1+z)*(diff(H(z), z))+3*H(z)^2+(1/2*((diff(X(z), z))^2+(1/2)*ZETA*exp(-sqrt(2/3)*X(z))*(diff(Y(z), z))^2))*H(z)^2*(1+z)^2-(1/4)*exp(-sqrt(2/3)*X(z))*Y(z)*(1-(1/2)*exp(-sqrt(2/3)*X(z))) = 0

-2*H(z)*(1+z)*(diff(H(z), z))+3*H(z)^2+((1/2)*(diff(X(z), z))^2+(1/4)*ZETA*exp(-(1/3)*6^(1/2)*X(z))*(diff(Y(z), z))^2)*H(z)^2*(1+z)^2-(1/4)*exp(-(1/3)*6^(1/2)*X(z))*Y(z)*(1-(1/2)*exp(-(1/3)*6^(1/2)*X(z))) = 0

(2)

NULL

``

NULL

NULL

diffux := solve(eq1, dif(H(z), z))

diffur := solve(eq2, dif(H(z), z))

NULL

NULL

NULL

NULL

NULL

NULL

``

Numeric*code

with(ListTools)

Seed := randomize()

with(stats[random])

sys := {subs(ZETA = 10, eq1), subs(ZETA = 10, eq2), subs(ZETA = 10, eq3)}

NULL

vv := 10^100; savf := []; L := 0; Digits := 30; MM := []; MMM := []; N := 1; kkk := []; MM; []; MMM := []

"for hh  from 1 by 1 to 1 do:L:=0: F:=0: b:=1: t:=2:while (t>b)do:"

n := 1.9; ZETA := 10; i := uniform[.60658, 1](N); ics := Y(i) = 1.8, (D(Y))(i) = 0, X(1) = .4, (D(X))(i) = 0, H(i) = .7; solution := dsolve({ics, op(subs(ZETA = 10, sys))}, {H(z), X(z), Y(z)}, type = numeric, method = bvp, output = listprocedure); m := [subs(solution, X(z))]; kk := [subs(solution, Y(z))]

"if op(kk(0))>.7 then  t:=(b)/(5): else t:=5*b :end if:end do: for T  from i by 10^(-1) to 1 do ls[T] := sqrt(0.29995*(1+ T)^(3)+5*10^(-5)*(1+ T)^(4)+0.7): sr[T] := op(kk(T)): L := L+(sr[T]-ls[T])^2 end  do:F:=sqrt(L): if F<vv  then vv:=F; sol:=solution:MM:=[op(MM),[vv,op(kk(1))]]:hhh:=vv:Pa:=[g,i]:else vv:=vv: MMM:=[op(MMM),vv]:end if:end do:"

Error, (in unknown) solution is only defined in the range .88696222680754726..1.

 

NULL

``

RH := subs(sol, Y(z)); Ry := subs(sol, X(z))

Error, invalid input: subs received sol, which is not valid for its 1st argument

 

Error, invalid input: subs received sol, which is not valid for its 1st argument

 

1-Mrad(1)+Rx(1)+Ry(1)

1-Mrad(1)+Rx(1)+Ry(1)

(3)

with(plots)

defHLCDM := sqrt(.29995*(1+z)^3+5*10^(-5)*(1+z)^4+.7)

plotqLCDM := plot((1+z)*(diff(defHLCDM, v))/defHLCDM-1, z = 0 .. 10, color = green, legend = ["q LCDM"])

plotqfR := [odeplot(sol, [z, Pa[1]*y(z)/(Pa[1]-1)+1], z = 0 .. 10, color = blue, legend = ["q R^n"])]; display(plotqLCDM, plotqfR)

plotHLCDM := plot(sqrt(.29995*(1+z)^3+5*10^(-5)*(1+z)^4+.7), z = 0 .. Pa[2], color = green, legend = ["H LCDM"], axes = boxed)

plotHfR := [odeplot(sol, [z, psi(z)], z = 0 .. Pa[2], color = blue, legend = ["H R^n"], axes = boxed)]; display(plotHLCDM, plotHfR)

 

psi*curve*fit

with(plots)

with(ListTools)

with(CurveFitting)

points1 := PolynomialInterpolation([[0, RH(0)], [1, RH(1)], [10, RH(10)], [100, RH(100)], [400, RH(400)], [800, RH(800)], [1200, RH(1200)], [1600, RH(1600)], [2000, RH(2000)], [2400, RH(2400)], [2800, RH(2800)], [3200, RH(3200)], [3600, RH(3600)], [4000, RH(4000)], [4400, RH(4400)], [4600, RH(4600)], [4800, RH(4800)], [5000, RH(5000)], [5200, RH(5200)], [5400, RH(5400)], [5600, RH(5600)], [5800, RH(5800)], [6000, RH(6000)], [6200, RH(6200)], [Pa[2], RH(Pa[2])]], v)

 

sd := plot(points1, z = 0 .. Pa[2], color = red, legend = ["curve fit"])

Error, (in plot) expecting a real constant as range endpoint but received Pa[2]

 

points11 := [[0, RH(0)], [.1, RH(.1)], [1, RH(1)], [10, RH(10)], [100, RH(100)], [400, RH(400)], [800, RH(800)], [1200, RH(1200)], [1600, RH(1600)], [2000, RH(2000)], [2400, RH(2400)], [2800, RH(2800)], [3200, RH(3200)], [3600, RH(3600)], [4000, RH(4000)], [4400, RH(4400)], [4600, RH(4600)], [4800, RH(4800)], [5000, RH(5000)], [5200, RH(5200)], [5400, RH(5400)], [5600, RH(5600)], [5800, RH(5800)], [6000, RH(6000)], [6200, RH(6200)], [Pa[2], RH(Pa[2])]]

sd := plot(points1, z = 0 .. Pa[2], color = red, legend = ["curve fit"], axes = boxed)

pntplot1 := pointplot(points11, symbol = BOX)

polycurve := PolynomialInterpolation(points11, z)

polyplot := plot(polycurve, z = 0 .. Pa[2], axes = boxed)

display([plotHLCDM, sd])

 

``

NULL

``

 

 

``

Luminosity*distnace

eq1h := diff(Hdi1(z), z)-1/points1 = 0

eq2h := diff(Hdi2(z), z)-1/defHLCDM = 0

sysh := {eq1h, eq2h}

icsh := Hdi1(0) = 0, Hdi2(0) = 0; solutionh := dsolve({icsh, op(sysh)}, {Hdi1(z), Hdi2(z)}, type = numeric, output = listprocedure)

plotLDistanceCFIT := [odeplot(solutionh, [z, (1+z)*Hdi1(z)], 0 .. Pa[2], color = blue, legend = ["Luminosity distance Curve fit"])]; plotLDistanceLCDM := [odeplot(solutionh, [z, (1+z)*Hdi2(z)], 0 .. Pa[2], color = red, legend = ["Luminosity distance LCDM"])]; display(plotLDistanceCFIT, plotLDistanceLCDM)

 

``

``

 

 

 

Download DistanceModulus.mw

 

sum2N := proc (N::integer) local summation, i, k; summation := 0; k := 0;

for i from 0 to N do if i = 1 then k := k+1

end if; summation := (i+k)^2 end do

end proc;
sum2N(10);

the result shows 121 but its not correct i think the right answer show be 2985
 

Hello MaplePrimes, 

So, I have used the discont=true option in the past and it has worked fine for me but for some reason with these functions I am using now the plots are still containing the veritcal asymptotes. Anyone spot something I am forgetting or doing incorrectly?

I have attached my maple file for easy viewing. 

Thanks. 

DiscontQuestion.mw

 

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