MaplePrimes Questions

Anteriorly, I had done a question that you answered in the forum and it basically it was about the simplification of a equation. I'm posting the print of the screen and the code because the question of today is similarly, but not completely, because there are something that make more complicate the code that I devolved.

restart;
Hi := -Delta*S1^2 - J*S1*S2;
R1 := S1*exp(-beta*Hi);
R1 := add(R1, S1 = [--1, 0, 1]);
R2 := exp(-beta*Hi);
R2 := add(R2, S1 = [-1, 0, 1]);
S := R1/R2;
S := convert(S, trig, {J*S2});
S := simplify(S);
S := convert(S, exp, {Delta});

In this case I had to put in evidence the therm exp(Delta beta), where I simplified the expression. Now, we have more 2 variables (+2 and -2) to substitute in the equation. The code is:

restart;
Hi := -Delta*S1^2 - J*S1*S2;
R1 := S1*exp(-beta*Hi);
R1 := add(R1, S1 = [-2, -1, 0, 1, 2]);
R2 := exp(-beta*Hi);
R2 := add(R2, S1 = [-2, -1, 0, 1, -2]);
S := R1/R2;
S := convert(S, trig, {J*S2});
S := simplify(S);
S := convert(S, exp, {Delta});

In the last line we had the final equation

What should I change in the code for that my exponential function continue in evidence? This is, for my expression  be

(4*sinh(2*J*S2*beta) + 2*sinh(J*S2*beta)*exp(-3*Delta*beta))/(2*cosh(2*J*S2*beta) + 2*cosh(J*S2*beta)*exp(-3*Delta*beta) + exp(-4*Delta*beta))

Hi everybody and Acer 

I have problems with this file I have, where it says “there where problems during the loading process” … Can anyone help med with my file?

Chemistry-Cheatsheet-Ramz_edition_Week_7-12_1_1.mw

i want to find fitted parameter value for G1,G2,G3,tau1,tau2,tau3 and plot stress-strain curve that fit to true_stress_strain curve(experimental data)
and i tried many times and still get error..can anyone please help me.here is my maple file...
 prony.mw 

Good day to all of you. 

I am working with a differential equation, got a first approximation setting all the constants equal to 1. But at the time to use the real values there appears the error numeric exception: division by zero.

I'll thanks any advice.

best regards

division_by_zero.mw

In the system below, I need to solve the solution algebraically (it is known in advance that from "V3" that a0=1,just open the V3 command).

V := exp(lambda*S) = S^4*a4 + S^3*a3 + S^2*a2 + S*a1 + a0;
V1 := subs(S = 2, V);
V2 := subs(S = 1, V);
V3 := subs(S = 0, V);
V4 := subs(S = -1, V);
V5 := subs(S = -2, V);
fsolve(subs(a0 = 1, {V1, V2, V4, V5}), {a1, a2, a3, a4});

I already know the answers, but I need maple to provide me with the command in the form

a1:=(1/6)*[8*sinh(lambda)-sinh(2*lambda)] and

a2:=(1/12)*[16*cosh(lambda)-cosh(2*lambda)-15],

a3:= ... etc.

What is the best way to do this?

Something to be aware of.  I realized you can't use rand in an equation with other rand's since the calculation affects the other call to it. 

Here is an example:

A simulation of 3 six sided die rolls added together for 50 trials. 

with(Statistics):
a:=[]:
for i from 1 to 50 do
  b:=rand(1..6)()+rand(1..6)()+rand(1..6)():
  a:=[op(a),b]:
end do:
Histogram(a,frequencyscale=absolute,discrete=true)

You'll notice the rand calls have affected the other calls to rand, and has eliminated some possible results.  

[added by moderator, from a Reply by the OP]

The idea was to generate values from 1 to 20 (I just chose 20 as an example) using 6 sided dice, and one that which produces as uniform a distrubution as possible. I appreciate the explanations.  I chose 4 as the smallest number of rolls needed. In the physical world as n approaches large numbers rolling that many becomes increasingly more difficult and time consuming.

So just wondering what the best solution would be for a uniform distribution in a range from 1 to n using only six sided dice?

For plotting with a plot function that has not been upgraded to units I want to remove units from the following

5.818576570*10^(-7)*exp(`–`((1.827959741*10^(-6))*(x^2+y^2)/Unit('`μm`')^2))/Unit('`μm`')^2

0.5818576570e-6*exp(-0.1827959741e-5*(x^2+y^2)/Units:-Unit(`μm`)^2)/Units:-Unit(`μm`)^2

(1)

convert(0.5818576570e-6*exp(-0.1827959741e-5*(x^2+y^2)/Units:-Unit(`μm`)^2)/Units:-Unit(`μm`)^2, unit_free)

0.5818576570e-6*exp((-0.1827959741e-5*x^2-0.1827959741e-5*y^2)*Units:-Unit(1/`μm`^2))

(2)

map(convert, 0.5818576570e-6*exp(-0.1827959741e-5*(x^2+y^2)/Units:-Unit(`μm`)^2)/Units:-Unit(`μm`)^2, unit_free)

0.5818576570e-6*exp((-0.1827959741e-5*x^2-0.1827959741e-5*y^2)*Units:-Unit(1/`μm`^2))

(3)

NULL


Anything else I could try with convert or something better than this

subs(Unit(1/'`μm`'^2) = 1, %)

I cannot conclude form the help page ?convert,unitfree if it should have worked on the expression.

Is the expression (1) non-scalar?

The term unit-free describes a scalar quantity with no (multiplicative) unit attached to it. Conversion to unit-free does not apply directly to any non-scalar Maple object or data structure, which may still have units embedded within it.

Download convert_unit_free_of_exp.mw

Download Exercises_all_lectures_1.mw

Exercises_all_lectures_1.mw

Hello,

I have a Maple document that contains a lot of notes that I have an exam for tomorrow. I opened the document today and it suggests I save a copy of a corrupt document and also it gives me the message "There were problems during the loading process.
Your worksheet may be incomplete." when it finally does load.

Any suggestions for how I could fix this would be greatly greatly appreciated.

Thank you

I have this equation:

and I need to do some manipulation to obtain this:

I manage to get it but my manipulation is too long for my liking. Can someone show me a shorter version. I have linked the Maple document.

Manipulating_polynomial.mw

Thank you in advance for your help.

Mario

Hello!
I am a Newbie to Maple and can´t figure out why Maple doesn´t compute the derivative explicitly of the following function. The first part of the derivative is "correct" and the second (yellow) part just says "D..". What am I doing wrong? Many thanks for your answers!!

 

Hi, I'm trying to solve these 2 nonlinear equations in f, g, and x, where x is from 0 to 1 with an increment of 0.1.

I am new to Maple and do not know the basics. Please try and help me. I'd highly appreciate it.

Since this is a nonlinear system, multiple solutions exist, I need to find the first 3 or 5 solutions. Once I solve the system, I would like to plot 2 plots, y-x and z-x.

Why does _EnvLinalg95 only affect  (and ) and not and ? 
 

restart;

m := <3 , 4 | 4 , 3>;

m := Matrix(2, 2, {(1, 1) = 3, (1, 2) = 4, (2, 1) = 4, (2, 2) = 3})

(1)

LinearAlgebra:-Eigenvalues(m);

Vector(2, {(1) = 7, (2) = -1})

(2)

LinearAlgebra:-Eigenvectors(m);

Vector(2, {(1) = -1, (2) = 7}), Matrix(2, 2, {(1, 1) = -1, (1, 2) = 1, (2, 1) = 1, (2, 2) = 1})

(3)

LinearAlgebra:-EigenConditionNumbers(m);

Vector(2, {(1) = 1.00000000000000, (2) = 1.00000000000000}), Vector(2, {(1) = 8., (2) = 8.})

(4)

_EnvLinalg95 := true:

whattype(m);

Matrix

(5)

LinearAlgebra:-Eigenvalues(m);

Vector(2, {(1) = 7, (2) = -1})

(6)

LinearAlgebra:-Eigenvectors(m):

Error, (in Matrix) invalid input: `Matrix/MakeInit` expects its 1st argument, initializer, to be of type list(list), but received [proc (i, j) options operator, arrow; `if`(j = 1 and i <= 2, (Vector(2, {(1) = 1, (2) = 1}))[i], rhs(fill_opt)) end proc]

 

LinearAlgebra:-EigenConditionNumbers(m);

Vector(2, {(1) = 1.00000000000000, (2) = 1.00000000000000}), Vector(2, {(1) = 8., (2) = 8.})

(7)

_EnvLinalg95 := false:

LinearAlgebra:-Eigenvectors(m);

Vector(2, {(1) = -1, (2) = 7}), Matrix(2, 2, {(1, 1) = -1, (1, 2) = 1, (2, 1) = 1, (2, 2) = 1})

(8)


 

Download _EnvLinalg95.mw

I have read the help page of Eigenvectors but couldn't find anything related.

how to find CharacteristicPolynomiall of matrix with vector entries? 

restart

with(LinearAlgebra)

with(ArrayTools)

M := Matrix([[-(I*2)*lambda+I*(lambda+m0), c], [-Transpose(c), I*a+I*(lambda+m0)]])

Matrix(%id = 36893490099698106484)

(1)

P := CharacteristicPolynomial(M, eta)

eta^2+(-I*a-(2*I)*m0)*eta+a*lambda-a*m0+c^2+lambda^2-m0^2

(2)

NULL

NULL

NULL

NULL

Download characpol.mw

This plot does not have units on the y-axis

Unit(('W')/'m'^2)*max(t/Unit('s'), 0);
plot(%, t = -Unit('s') .. 2*Unit('s'));

Any idea why and how to get them back when max is involved?

Hello,

I want to use the spline options in the SavitzkyGolayFilter, but I don't understand the description in the Maple help. Can someone give me Sytax examples? I would also like to specify the 1st and 2nd derivatives of the endpoints.

I am grateful for any help!

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