# Items tagged with toto Tagged Items Feed

### Some Expression Manipulation Questions!...

August 30 2014
1 14

1-Suppose that after applying the command "factor(f)" the "f "takes the form:

f=(BesselJ(0,r))*(A very lengthy term)

Is there a way to force maple to show f like below:

f=(A very lengthy term)*(BesselJ(0,r))

2-Suppose f is written as follows:

f=a*b*x+a*b*y

Can you suggest a way (without using "op" command) to write f as:

f=a*(b*x+b*y)

### Error, (in f) unable to store .......................

May 27 2014
0 2

Hello Hello everybody
I have to solve the following differential equation numerically

 > restart:with(plots):
 > mb:=765 : mp:=587 : Ib:=76.3*10^3 : Ip:=7.3*10^3 : l:=0.92 : d:=10: F:=490: omega:=0.43 :
 > eq1:=(mp+mb)*diff(x(t),t\$2)+mp*(d*cos(theta(t))+l*cos(alpha(t)+theta(t)))*diff(theta(t),t\$2)+mp*l*cos(alpha(t)+theta(t))*diff(alpha(t),t\$2)+mp*(d*diff(theta(t),t)^2*sin(theta(t))+l*(diff(theta(t),t)+diff(alpha(t),t))^2*sin(alpha(t)+theta(t)))-F*sin(omega*t)=0;
 (1)
 > eq2:=(mp+mb)*diff(z(t),t\$2)-mp*d*(sin(theta(t)+alpha(t))+sin(theta(t)))*diff(theta(t),t\$2)-mp*l*sin(alpha(t)+theta(t))*diff(alpha(t),t\$2)+mp*(d*diff(theta(t),t)^2*cos(theta(t))+l*(diff(theta(t),t)+diff(alpha(t),t))^2*cos(alpha(t)+theta(t)))+9.81*(mp+mb)-F*sin(omega*t)=0;
 (2)
 > eq3:=mp*(d*cos(theta(t))+l*cos(alpha(t)+theta(t)))*diff(x(t),t\$2)-mp*(l*sin(theta(t)+alpha(t))+d*sin(theta(t)))*diff(z(t),t\$2)+(Ip+Ib+mp*(d^2+l^2)+2*mp*d*l*cos(alpha(t)))*diff(theta(t),t\$2)+[Ip+mp*l^2+mp*d*l*cos(alpha(t))]*diff(alpha(t),t\$2)-mp*sin(alpha(t))*(l*d*diff(alpha(t),t)^2-l*d*(diff(alpha(t),t)+diff(theta(t),t))^2)+mp*9.81*l*sin(alpha(t)+theta(t))+mp*9.81*d*sin(theta(t))=0;
 (3)
 > eq4:=mp*l*cos(alpha(t)+theta(t))*diff(x(t),t\$2)-mp*l*sin(alpha(t)+theta(t))*diff(z(t),t\$2)+(Ip+mp*l^2+mp*d*l*cos(alpha(t)))*diff(theta(t),t\$2)+(Ip+mp*l^2)*diff(alpha(t),t\$2)-mp*9.81*l*sin(alpha(t)+theta(t))+l*d*mp*diff(theta(t),t\$1)^2*sin(alpha(t))=0;
 (4)
 > CI:= x(0)=0,z(0)=0,theta(0)=0,alpha(0)=0,D(x)(0)=0,D(alpha)(0)=0,D(z)(0)=0,D(theta)(0)=0;
 (5)
 > solution:=dsolve([eq1,eq2,eq3,eq4, CI],numeric);
 Error, (in f) unable to store '[0.]/(0.17571268341557e16+[-0.25659510610770e15])' when datatype=float[8]

I don't know why it says : Error, (in f) unable to store '[0.]/(0.17571268341557e16+[-0.25659510610770e15])' when datatype=float[8]

Help pleaase!

thank you !!!

### General solution for differential equations...

May 09 2014
1 5

Diff_EQ_sample_questions.pdf

This is a link to two sample questions I am trying to learn how to solve using maple. I am using maple student edition of maple. Any help would be great. Thank you.

### How to obtain animated solution of PDE...

March 21 2014
0 0

Hi

I need a temperature distribution inside a barrier during a heating process.
I will be appreciated for any help.

wz

How to animete BC using varying temperature in time?  How to obtain animated solution?

 >

Diffusivity coefficent...

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Thickness of barrier...

 >

Heating curve:
Time in heating curve (in hours form exmaple)...

 >

Varying temperature in time [K]....

 >

Initial temperature [K]

 >
 >

--->>>

 >
 >
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 >

### Find Trendline and R-squard value from data...

March 10 2014
1 1

Hi

I have some data:

Matrix(10, 2, {(1, 1) = 0, (1, 2) = 0, (2, 1) = .5, (2, 2) = 3.25, (3, 1) = 1.0, (3, 2) = 5.82, (4, 1) = 1.5, (4, 2) = 7.50, (5, 1) = 2.0, (5, 2) = 8.79, (6, 1) = 2.5, (6, 2) = 9.83, (7, 1) = 3.0, (7, 2) = 10.66, (8, 1) = 3.5, (8, 2) = 11.35, (9, 1) = 4.0, (9, 2) = 11.94, (10, 1) = 4.5, (10, 2) = 12.46})

I want Maple to make a trendline fitting a Logarithmic function. I can make it output some function with this:

LeastSquares(`<,>`(.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5), `<,>`(3.25, 5.82, 7.50, 8.79, 9.83, 10.66, 11.35, 11.94, 12.46), x, curve = a+b*ln(x))

It outputs:

5.96497783539274+4.25309474196387*ln(x)

But please notice, the dataset in the function does not have the first 0 and 0. If i do that:

LeastSquares(`<,>`(0, .5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5), `<,>`(0, 3.25, 5.82, 7.50, 8.79, 9.83, 10.66, 11.35, 11.94, 12.46), x, curve = a+b*ln(x))

It outputs:

Error, (in Matrix) numeric exception: division by zero

Besides that, i need the R-squard value for determinating how well it fits.

If i do the same thing i Excel the data set will give a formular: 5.5464ln(x)-0.2175 with a R-sward value of 0.9985.

How can i do this i maple?

----

Emil Kristensen

### How to solve Bvp...

March 08 2014
1 11

Thank you for your help with this question. I found what I was looking for.

### convert Matlab code to Maple...

February 23 2014
0 1

Dear all

I would like to convert Matlab code to Maple, is there anu idea, this is the code.

% Usage: [y t] = abm4(f,a,b,ya,n) or y = abm4(f,a,b,ya,n)
% Adams-Bashforth-Moulton 4-th order predictor-corrector method for initial value problems
% It uses
% Adams-Bashforth 4-step method as a precdictor,
% Adams-Moulton 3-step method as a corrector, and
% Runge-Kutta method of order 4 as a starter
%
% Input:
% f - Matlab inline function f(t,y)
% a,b - interval
% ya - initial condition
% n - number of subintervals (panels)
%
% Output:
% y - computed solution
% t - time steps
%
% Examples:
% [y t]=abm4(@myfunc,0,1,1,10);          here 'myfunc' is a user-defined function in M-file
% y=abm4(inline('sin(y*t)','t','y'),0,1,1,10);
% f=inline('sin(y(1))-cos(y(2))','t','y');
% y=abm4(f,0,1,1,10);

function [y t] = abm4(f,a,b,ya,n)
h = (b - a) / n;
h24 = h / 24;

y(1,:) = ya;
t(1) = a;

m = min(3,n);

for i = 1 : m % start-up phase, using Runge-Kutta of order 4
t(i+1) = t(i) + h;
s(i,:) = f(t(i), y(i,:));
s2 = f(t(i) + h / 2, y(i,:) + s(i,:) * h /2);
s3 = f(t(i) + h / 2, y(i,:) + s2 * h /2);
s4 = f(t(i+1), y(i,:) + s3 * h);
y(i+1,:) = y(i,:) + (s(i,:) + s2+s2 + s3+s3 + s4) * h / 6;
end;

for i = m + 1 : n % main phase
s(i,:) = f(t(i), y(i,:));
y(i+1,:) = y(i,:) + (55 * s(i,:) - 59 * s(i-1,:) + 37 * s(i-2,:) - 9 * s(i-3,:)) * h24; % predictor
t(i+1) = t(i) + h;
y(i+1,:) = y(i,:) + (9 * f(t(i+1), y(i+1,:)) + 19 * s(i,:) - 5 * s(i-1,:) + s(i-2,:)) * h24; % corrector
end;

### how to do not to have maple simplify what I wrote....

December 10 2013
1 2

Dear people being here,

I have a question.

When I wrote as

aa:=(delta[1]*n[1])/(n[f1]*delta[1]);

maple returned as

aa := n[1]/n[f1]

How can I have maple express the original one, aa:=(delta[1]*n[1])/(n[f1]*delta[1]), not what returned to me?

I hope you will answer to my question.

taro

### unable to match delimiters...

December 02 2013
0 2

I am to program a computation on maple.
But I get the message :

Error, unable to match delimiters

followed by the full sequence of command.

How can I do to fix this problem?

### Plot Interface and Euler Angles...

October 26 2013
0 2

Can someone explain to me, if you can, how the Euler angles on the plot interface work?

It looks like Phi is the rotation around z, Theta is the rotation around x, and Psi is around y. I'm trying to use matrices to compute the vector that is pointing towards your face as you're looking at the plot with the given Euler angles.

X := Matrix(3, 3, {(1, 1) = 1, (1, 2) = 0, (1, 3) = 0, (2, 1) = 0, (2, 2) = cos(phi), (2, 3) = sin(phi), (3, 1) = 0, (3, 2) = -sin(phi), (3, 3) = cos(phi)});

Y := Matrix(3, 3, {(1, 1) = cos(theta), (1, 2) = 0, (1, 3) = sin(theta), (2, 1) = 0, (2, 2) = 1, (2, 3) = 0, (3, 1) = -sin(theta), (3, 2) = 0, (3, 3) = cos(theta)});

Z := Matrix(3, 3, {(1, 1) = cos(psi), (1, 2) = sin(psi), (1, 3) = 0, (2, 1) = -sin(psi), (2, 2) = cos(psi), (2, 3) = 0, (3, 1) = 0, (3, 2) = 0, (3, 3) = 1});

and computing X*Y*Z*e3

TIA!

### convert BSplineCurve to function...

September 09 2013
1 0

i interpolate a function in some knots by BSplineCurve, the resulting function is parametric.

how i can convert this parametric function to a function?

thanks.

### How do I figure normal distribution, z value using...

March 18 2013
0 1

((x-6.05)/sqrt(.0004/9) < (6.035-6.05)/sqrt(.0004/9))

Maple comes up with P(150.000000000x<905.2500000), but I cant get Maple to tell me

P(Z<-2.25).. How can I get it to calculate and tell me to use Z tables ?

### How do I use Maple to construct a stem and leaf di...

March 12 2013
0 4

Twenty five observations of a random variable X are :130.8  129.9  131.5  131.2  129.5  132.2  133.7  127.8  131.5  132.7  134.8 131.7  133.9  129.8  131.4  132.8  132.7  128.8  130.6  131.1  133.8  130.5 131.4  131.3  129.5  //.. How do I construct a stem and leaf display using stems of 127, 128, 129, ... 134? I also need to find all quartiles.. Thank you to anyone...

### How can I use Maple to determine z scores?...

March 02 2013
3 4

If Z is N(0,1) find

a) P(0<=Z<=.87)

I understand how to get to 0-0/1<=Z-0/1<=.87-0/1

which ends up being OI(.87), but am not sure how to get this to calculate. Plus I ant use proper functions here becuase I dont have the pallette, but OI is an O with the I through it... Φ(.87) I beleive....

I dont know how to have Maple calculate ths to give me the correct normal distribution value.

### How do I find the vertical asymptote of tan(x) whe...

March 01 2013
0 2

How do I find the vertical asymptote of tan(x) when x=x/x+1?

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