4 years, 99 days

## Re: Substituting an expression...

Maple 2023

Hello there,

Is there any chance to ask for your expertise in this issue of substitution?

I tried to make the expression 'eq_m1' to 'eq_m1_desired' by substituting 'L__ads*L__fd/(L__fd + L__ads)' as 'L__ads_p', but did not succeeded, after a series of different attempts. Would you show me how to achive the desired expression?

 > restart;
 > with(LinearAlgebra):
 > with(DynamicSystems):
 > interface(imaginaryunit=j):
 > eq_m1 := m1 = (X__Tq*E__B*sin(delta) - R__T*E__B*cos(delta))/(R__E^2 + 2*R__a*R__E + R__a^2 + X__E^2 + X__E*L__ads*L__fd/(L__fd + L__ads) + 2*X__E*L__l + L__aqs*X__E + L__aqs*L__ads*L__fd/(L__fd + L__ads) + L__aqs*L__l + L__l*L__ads*L__fd/(L__fd + L__ads) + L__l^2);
 (1)
 > eq_m1_desired := m1 = (X__Tq*E__B*sin(delta) - R__T*E__B*cos(delta))/(R__E^2 + 2*R__a*R__E + R__a^2 + X__E^2 + X__E*L__ads_p + 2*X__E*L__l + L__aqs*X__E + L__aqs*L__ads_p + L__aqs*L__l + L__l*L__ads_p + L__l^2);
 (2)
 > ######
 >

## RE: LieDerivative...

Maple 2022

Hello there,

Is there any chance to ask this one question?

The attached (following) worksheet shows the result of LieDerivative operation, which is not correct.

The correct answer is given in the image in the middle of the worksheet. Is there any particular reason regarding Maple's way of conducting the operation in that way?

 > restart;
 > with(LinearAlgebra):
 > with(DifferentialGeometry):
 > with(LieAlgebras):
 > DGsetup([x1, x2], M, verbose);
 (1)
 >
 M > f := evalDG((x2)*D_x1 + (c1 * (1 - x1^2) * x2 - c2 * x1)*D_x2);
 (2)
 M > h := evalDG((x1)*D_x1 + (0)*D_x2);
 (3)
 M >
 M > LieDerivative(f, h);
 (4)
 M >

## RE: simplifying a numerical representati...

Maple 2022

Hello there,

Is there any chance to ask if there is a way to simplify the numeric outcome from an operation?

Here is what I've been trying:

 > restart;
 > with(LinearAlgebra):
 > interface(imaginaryunit=j):
 > Amat := Matrix(2, 2, [[-0.1428571428*K__D, -0.1081971238], [376.9911185, 0]]);
 (1)
 > Eigenvalues(Amat);
 (2)
 > Desired := sqrt((2.000000000*10^(-10))^2 * (1.275510203*10^17*K__D^2 - 1.019733868*10^21));
 (3)
 >

I tried to simplify the Eigen values, to make them in the formality of the 'Desired' numerical expression, but no success yet.

Thank you,

## RE: How to collect an expression by a te...

Maple

Hello there,

Is there any chance to see that the 'eq_5_22_desired' expression shown below can be derived from a collection of the commands. similar to what's given in the 'eq_5_22a'? In other words, is it possible to make Maple aware of the point that 'L__ad/(L__ad + L__fd)' can be interpreted as 'L__ad*L__fd/(L__ad + L__fd) * 1/L__fd'?

 > restart;
 > with(LinearAlgebra):
 > interface(imaginaryunit=j):
 (1)
 (2)
 > eq_5_23 := L__ad__p = evala(rhs(eq_5_23x));
 (3)
 (4)
 >

## Re: How to collect using a term by multi...

Maple 2022

Hello there,

Would you allow me to ask this question?

Is there any way to apply 'collect' command using a term by multiplication of variables?

The following worksheet shows an example. What I wanted to see is the 'desired' expression, while multiple attempts with 'collect' command failed.

 > restart;
 > eq_e5_10z := Psi[q0]*Delta*delta = 1/(omega[0])*p(Delta*Psi[q])+Delta*Psi[d]+Psi[d0]*1/(omega[0])*p(Delta*delta);
 (1)
 > eq_e5_10za := Delta*Psi[d] = Psi[q0]*Delta*delta - op(1, rhs(eq_e5_10z)) - op(3, rhs(eq_e5_10z));
 (2)
 > eq_e5_10zb := subs({p(Delta*Psi[q])=0}, eq_e5_10za);
 (3)
 > collect(rhs(eq_e5_10zb), {Delta*delta});# error
 > collect(rhs(eq_e5_10zb), [Delta*delta]);# error
 > collect(rhs(eq_e5_10zb), [Delta, delta]);# did not work
 (4)
 > Desired := (psi__q0 - psi__d0*p/omega__0)*(Delta*delta);
 (5)
 >