Maple Questions and Posts

These are Posts and Questions associated with the product, Maple

 

For many years I succesfully used the command:

Lambda := ImportMatrix(LambdaFile, delimiter = "", datatype = string);

 

but for some txt files I now got the following error in Maple 2016:
Error, (in ImportMatrix) cannot interpret file

The same code still runs without problems at all in previous versions of Maple.

The strange thing is that other txt files can be still be imported in Maple 2016 without problems.

I will upload two files:

ULSlx3.txt returns an error message

ULStd3.txt no problems

ULSlx3.txt

ULStd3.txt

complete code:

restart;
with(LinearAlgebra); with(Statistics);
interface(rtablesize = infinity);
with(Typesetting):
interface(typesetting=extended):

LambdaFile := "C:/path/ULSlx3.txt";
Lambda := Matrix(5, 1);

in the whatsnew there is no information on changes with respect to the ImportMatrix command, although there is some (unrelated) information on Importing Data:

Importing Data
By default, the Import command now returns a DataFrame when importing from Excel, CSV, DIF, and TSV file formats, and returns a DataSeries when importing from ODS, SXC, and TSV file formats. Use the output option to specify a different format. For example, Import(origin, output=Matrix).

 

I have no clue what is wrong with my code and why some text files can be imported as before whereas other files returns an error message.

greetings Harry

In using Maple there are many ways to complete a command on a function. Using shortcuts in the worksheet/document you can enter the command on the line rather than using the drop down menus or clickable math menu.  I would like to see what the shortcut command are for the packages in Maple.  There are so many, I am using the LinearAlgebra package and have seen Dr. Lopez use " ||A||2 to determine the Euclidean Norm of A.  But where does this use get described in the help or examples of other shortcut usage for Maple. I've seen the shortcut commands for Documents in General, but the use of shortcut commands for other packages  don't seem to discuss the usage of such shortcuts.

Is there a document that documents these shortcuts.

 

Hi my dear friends, sorry for boring you. I am hauted by a problem about 'mtalyor'.

I failed to expand the following equation by using the following command:

u:=x(t)/sqrt(x(t)^2+y(t)^2-2*x(t)+1)*diff(y(t),t);
indets(u,name);
w:=evalindets(u,function(identical~({x(t),y(t)})),s->op(0,s)(freeze(op(s))));
var:=indets(w,name) minus {t};
mtaylor(w,var,4);
thaw(%)

 Freeze is applied to the part in which the expansion will take place, obviously it didn't work well. 

Thank you in advance for taking a look. 

To gererate a random initail cofigration -1 or 1

spin = (-1).^(round(rand(N)));

 

for i=1:1000,

 

neighbours = circshift(spin, [ 0 1]) + ...

circshift(spin, [ 0 -1]) + ...

circshift(spin, [ 1 0]) + ...

circshift(spin, [-1 0]);

how to do this in maple?

Hello

I was looking for information on how to solve a differential equation in Maple, but I do not know how to start.

I have yet equations in symbolic form and I want to apply for the calculation of such a procedure ODE4 (Runge Kutta 4) with fixed step integration Tc and time calculations ongoing T.

Where to start?
1. This should be done in another sheet, or I could write command in next line under the symbolic transformations?
2. To enter numeric parameters that certain symbols were they equal?
3. How to perform iterative calculations?

Thank you in advance for your help

I am curious, can simplify/siderels be executed in mod p by some equivalent Maple function call?

Hi, I have the equations (below) with different parameters. I'd like to find out if is it possitble to:

(1) Create a loop that solves for values of on of the parameters, T, in the interval -0.3<T<0.3 and obtain the solutions allowing for a grid of 0.01.

That is, if one can first solve for T= -0.3 and then use the loop with increments that raise T by 0.01 each time until T=0.3. Other parameters are held constant at their assigned values.

(2) Generates the corresponding vectors for T and all the endogenous variables.

eq1 := PI_T = alpha*M*(kappa/(1+kappa-sigma)-1):
eq2 := l = alpha*((sigma-1)*kappa/(1+kappa-sigma)+1):
eq3 := M = phi_c^(-kappa)*F:
eq4 := e*F = PI_T*v+T:
eq5 := M*l+L_A = L_s:
eq6 := F*e+A = A_s:
eq7 := A = (1-beta)*(L_s+(1-v)*PI_T-T):
eq8 := A_s = L_A:
eq9 := p = sigma/((sigma-1)*phi):
eq10 := P_Y = M^(lambda/(1-sigma))*p:
eq11 := L_s = N*(theta*P_Y^beta)^(-1/delta):
eq12 := phi = (kappa/(1+kappa-sigma))^(1/(sigma-1))*phi_c:
eq13 := U = delta*theta*L_s/((1+delta)*P_Y^beta)+((1-v)*PI_T-T)/P_Y^beta:

Params:= [ T=0, N = 1, v = 1, beta = .75, lambda = 1, sigma = 5, kappa = 4.8, delta = 2, theta = 2.591350635, alpha = 0.3998699153e-1, e = 0.8333333332e-1]:

Init_Values:= {A_s = .2500000000, l = .9996747882, PI_T = 0.8333333332e-1, L_A = .2500000000, phi = 1.878101496, M = .4168022157, A = .1666666667, p = .6655657336, P_Y = .8283396488, L_s = 2/3, phi_c = 1.2, F = 1, U = 1.326439132 }:


SOL:= fsolve(eval({eq||(1..13)}, Params), Init_Values);

 

Many thanks!!

Hello there,

 

Suppose I have a parametric experssion like   P(ε)=1+ε+ε23 where ε is very small. How can I get P(ε)≈1+ε or P(ε)≈1+ε+ε2

 

Thanks

I would like to remove from a table, the index that verifies some constraint.

For example :

restart:
a := table([1=c, 2=g, 3=y]);

for k in [indices(a, `nolist`)] do
  if is(k, even) then
    a[k] := 'a[k]':
  end if:
end do:

# This does not work as expected 
eval(a);


I have found this workaround 

b := map(u -> if `not`(is(u, even)) then u=a[u] end if, [indices(a, `nolist`)]);
eval(b);

But is there a way to force Maple to evaluate k to 2 before it "unevaluate"  'a[k]' ?

 

I would like to know , what is the command that i able to carry out (simple one) such that I able to shaded the region between y=x^2 and y-axis from y= 0 to y=4.

Hi all

If I have an expression:

B := int(A(x), x = -infinity .. infinity)

How can I use a statement to extract A(x) when A(x) is quite complecated during calculation. thanks

" there were problems during the loading process. your worksheet may be incomplete"

I have seen some other people having this problem, I have tried to erase the bad characters myself but I can't seem to do it right. Can someone pleeeease help me? :(

 

https://drive.google.com/file/d/0B5FKHYOiyQ0jMk9XNzBYU3FDbzQ/view?usp=sharing

Hello.

int(floor(x^2), x = 0 .. 2) = 6 , but it should be 1.85374.

 

 

Bug_in_integrate(floor_and_ceil).mw

Mariusz Iwaniuk

 

With the following equation

eqn:=y=1/2+(1/2)*erf((1/2)*sqrt(2)*(x-mu)/sigma)-exp(-lambda*(x-mu)+(1/2)*lambda^2*sigma^2+ln(1/2-(1/2)*erf((1/2)*sqrt(2)*(lambda^2*sigma^2-lambda*(x-mu))/(lambda*sigma))));

and with

x:=solve(eqn,x) assuming sigma > 0, lambda > 0;

I got the following solution

x := -(1/2)*(-lambda^2*sigma^2-2*lambda*mu+2*RootOf(-exp(_Z)*erf((1/4)*sqrt(2)*(lambda^2*sigma^2+2*_Z)/(lambda*sigma))+exp(_Z)+erf((1/4)*sqrt(2)*(-lambda^2*sigma^2+2*_Z)/(lambda*sigma))+2*y-1))/lambda;

In order to get rid of RootOf I gave the command:

allvalues(%);

However, RootOf did not disappear. How should I proceed? 

 

hi

if possible to convert matlab file in to maple fie program??convert_to_maple_program.txt

thanks

 

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