Maple Questions and Posts

These are Posts and Questions associated with the product, Maple

How do I solve for nonlinear differential equation with boundary value problem? Is it possible to solve nonlinear ODE by using Laplace Transform with Maple? If possible, can give me an example of solving nonlinear ODE using Maple. Thank you.

0.733333e^-1

0.733333e^-3

0.733333e^-5

0.733333e^-7

 

no matter what e is , expect to output the same 0.733333

 

I am trying to plot y:=x^2+x-12 as a curve and as a series of point. It is just not working. Suggestions, please.

Digitalize.mw
 

restart

f := proc (x) options operator, arrow; x^2+x-12 end proc

n := 10

h := 5``

printf("\n    i        x       f (dec.form)    f (sci. notat.)\n"); printf("  ---------------------------------------------------\n"); for i from 0 to n do X[i] := i*h; Y[i] := f(X[i]); printf(" %5d  %9.4f  %13.9f  %17.10e\n", i, X[i], Y[i], Y[i]) end do


    i        x       f (dec.form)    f (sci. notat.)
  ---------------------------------------------------
     0     0.0000  -12.000000000  -1.2000000000e+01
     1     5.0000   18.000000000   1.8000000000e+01
     2    10.0000   98.000000000   9.8000000000e+01
     3    15.0000  228.000000000   2.2800000000e+02
     4    20.0000  408.000000000   4.0800000000e+02
     5    25.0000  638.000000000   6.3800000000e+02
     6    30.0000  918.000000000   9.1800000000e+02
     7    35.0000  1248.000000000   1.2480000000e+03
     8    40.0000  1628.000000000   1.6280000000e+03
     9    45.0000  2058.000000000   2.0580000000e+03
    10    50.0000  2538.000000000   2.5380000000e+03

 

``

plot1 := plot([X[k], Y[k]], k = 0 .. n, style = point, symbol = soliddiamond, symbolsize = 24, color = blue)

plot2 := plot(f(x), x = 0 .. 50)

with(plots)

display([plot1, plot2])

 

``


 

Download Digitalize.mw

 

 

restart;

with(IntegrationTools):

# A very simple double integral

J:=Int(Int(x^2, x = 0 .. y), y = 0 .. 1);

Int(Int(x^2, x = 0 .. y), y = 0 .. 1)

(1)

value(J);

1/12

(2)

# Try a simple change of variables

Change(J, x=t*y, [t]);   # Why this form?

Intat(Intat(_a^2, _a = _b)-Intat(_a^2, _a = 0), _b = 1)-Intat(Intat(_a^2, _a = _b)-Intat(_a^2, _a = 0), _b = 0)

(3)

value(%);

1/12

(4)

# Now the same for 2*J

Change(2*J, x=t*y, [t]);  # OK, but why?

2*(Int(y^3*(Int(t^2, t = 0 .. 1)), y = 0 .. 1))

(5)

value(%);

1/6

(6)

 


Download IntegrationTools-Change.mw

Hello

I found this paper. 

http://benson-labs.com/uploads/stuff/POW15.pdf

I'm not sure if the population after 1 year is correct.

I wanted to get the formula from rsolve. But i have incorrorectly formulated the sum by day and the total.

Rattus_recursion.mw

 

Whilst trying to debug another problem on this site, this one

https://www.mapleprimes.com/questions/225688-How-To-Compute-Inverse-Of-A-Matrix-For

I came across a Maple bug(?) which was so serious, I thought either

  1. I'm being more than usually dim
  2. it needs it's own entry here, so that others can check

Problem can be summarized as:

When using 2D input, can the '.' character be used for simple matrix multiplication???? Because it isn't working for me!

Entering the '.' character places a bold, midline dot between the two arguments, but executing the result gives "Error unable to parse". Converting to 1-D input, no issues - everything works as expected.I should also point out that

  1. I never normally use 2D-input for my own work
  2. the attached worksheet executes correctly in Maple 2017.3, X86 64 WINDOWS, Sep 13 2017, Build ID 1262472.

If this is reproducible then wtf!

restart; with(LinearAlgebra); kernelopts(version)

`Maple 2018.1, X86 64 WINDOWS, Jun 8 2018, Build ID 1321769`

(1)

A := RandomMatrix(2, 2); B := RandomMatrix(2, 2)

Matrix(2, 2, {(1, 1) = 44, (1, 2) = -31, (2, 1) = 92, (2, 2) = 67})

 

Matrix(%id = 18446744074378134462)

(2)

A.B

Error, unable to parse

"A*B;"

 

LinearAlgebra:-Multiply(A, B)

Matrix(%id = 18446744074378136502)

(3)

A:= RandomMatrix(2, 2);
B:= RandomMatrix(2, 2);
A.B

Matrix(2, 2, {(1, 1) = -32, (1, 2) = -4, (2, 1) = -74, (2, 2) = 27})

 

Matrix(2, 2, {(1, 1) = -93, (1, 2) = -72, (2, 1) = -76, (2, 2) = -2})

 

Matrix(%id = 18446744074378132406)

(4)

 

Download matMulProb.mw

I'm start making an homepage about mathematic and wondt to link a workpage writen in Maple 16 into WP, thanks to whose ho have any idea :)

 

Hello,

I have a set of nonlinear equations (transcendental) containing variables and one free parameter. I want to solve this system for variables while varying parameter's value. I have tried with fsolve and solve commands keeping fixed the parameter value, but they are not solving yet. Is there any way to solve this system for a range of parameter's value.
The systmem is like this, x,y,z are the variables and 'a' is the parameter:
f1(x,y,z,a)=0,
f2(x,y,z,a)=0,
f3(x,y,z,a)=0.

Many thanks in advance.

Hi,

I submit you this strange result:
for somenumerical  values of a, b, c  (a, b, c real and b > a), Maple 2018 is not able to compute the mean of
c*U where U is a Uniform random variable with support [a, b].


 

restart:

with(Statistics):

interface(version);

`Standard Worksheet Interface, Maple 2018.0, Windows 7, March 10 2018 Build ID 1298750`

(1)

z := .4070716688*RandomVariable(Uniform(0.12-0.02*0.12, 0.12+0.02*0.12));
Mean(z);

.4070716688*_R

 

Error, (in Statistics:-Mean) the expression does not have a taylor expansion at t = 0

 

z := .4070716688*RandomVariable(Uniform(a, b));
Mean(z);
subs({a=0.12-0.02*0.12, b=0.12+0.02*0.12}, %);

.4070716688*_R0

 

.2035358344*a+.2035358344*b

 

0.4884860026e-1

(2)

 


 

Download Mean.mw


PLEASE: Maple still fails if I replace  a = 0.12 -0.02*0.12 by its value 0.1174
                                                                       and b = 0.12+0.02*0.12 by its value 0.1224
                   

This is incomprehensible and could hide a more profound problem.

Good day everyone,

I am trying to write HAM code for coupled ODE but getting errors like "table(...)" or

 

"Error, (in dsolve) found the independent variables {eta} also present in the names of the functions of the system {(diff(diff(diff((table( [( 0 ) = proc (eta) options operator, arrow, function_assign; eta*exp(-eta)-F[w] end proc ] ))(eta), eta), eta), eta))(f[1](eta)), (diff(diff((table( [( 0 ) = proc (eta) options operator, arrow, function_assign; exp(-eta) end proc ] ))(eta), eta), eta))(theta[1](eta)), (diff((table( [( 0 ) = proc (eta) options operator, arrow, function_assign; eta*exp(-eta)-F[w] end proc ] ))(eta), eta))(f[1](eta)), ((table( [( 0 ) = proc (eta) options operator, arrow, function_assign; exp(-eta) end proc ] ))(eta))(theta[1](eta))}"

 

Anyone with useful informations should please help.

Thank you.

Below is the attached of the file

untitled22222.m

With this application, you visualize the DNA chain using the position vector as a fundamental tool to describe its curvature and radius of curvature. I also show the native maple syntax for the graphics. You can download the maple center app to show different DNA trajectories based on the position vector. Developed for students of health sciences.
 

k_adn.zip  (In spanish)

https://www.maplesoft.com/applications/download.aspx?SF=154486/Plot_of_curvature_and_radius_of_curvature.mw

Lenin Araujo Castillo

Ambassador of Maple

Does Maple have a way to upload a screenshot of a worksheet or a savefile of a worksheet to MaplePrimes?

Hi.

How I can Plot voltage (v) versus time (t) in nonlinear differential equation.

if possible please provide a simple example for me. for instance the command that I must use!!

plot.pdf

Hello everyone, i've a problem working with Maple because i have a really big system of equations and for everything that i have to do with them, for example, collect terms, coefficients, take a lot of time from me. The problem it is when, for example, i wait 30 minutes to take the coefficients from a equation and in the next command Maple might stop, then i have to close and start all over again... My question it is if have anyway to save my file in a way that if i close and re open i dont have to compile all again. Maybe this is pretty obvious but i really dont know how to do it, because if i close my work and open again, i have to compile everything again.

Following creates a list of 10 numbers 1..10:

  L := []; for i from 1 to 10 do L := [op(L), i] end do;

Now suppose I have equations labelled (1) ... (10). Can I place these equations into a list by some analogy of the above code using the label references?

 

 

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