MaplePrimes Questions

How do people test BIBD design in maple?

what are the different when using different field when test design ?

how to design a game that is suitable for the specified field of the design?


I have assumed lambda <-1 yet signum(lambda) returns lambda~.  It should be -1. I need to show that the expression lambda is used in is negative. 

restart

NULL

assume(t > 0, k > 1, lambda = 'real', mu = 'real', mu = 'real', lambda+mu+nu = 1)

about(lambda)

Originally lambda, renamed lambda~:

  Involved in the following expressions with properties
    -real+lambda assumed `property/object`[0]
    lambda+mu+nu assumed `property/object`[1]
  also used in the following assumed objects
  [-real+lambda] assumed 0
  [lambda+mu+nu] assumed 1

 

signum(lambda)

signum(lambda)

(1)

additionally(lambda <= -1)

about(lambda)

Originally lambda, renamed lambda~:

  Involved in the following expressions with properties
    -real+lambda assumed `property/object`[0]
    lambda+mu+nu assumed `property/object`[1]
  is assumed to be: RealRange(-infinity,-1)
  also used in the following assumed objects
  [-real+lambda] assumed 0
  [lambda+mu+nu] assumed 1

 

signum(lambda)

signum(lambda)

(2)

sCDB := (4*(k-1))*(k+1)*`&lambda;`*t^3/((t^2+1)^2*(k^2*t^2+1))

4*(k-1)*(k+1)*lambda*t^3/((t^2+1)^2*(k^2*t^2+1))

(3)

signum(sCDB)

signum(lambda)

(4)

``


 

Download signum_problem.mw

I am trying to add a specific property (radiation length) to the Elements in ScientificConstants.

To do this  I first 

ScientificConstants:-AddProperty(radiationlength); # this seems to work

I then load a table of element name - radiationLength pairs (it is really a bigger table but only these are of interest):

data:=ImportMatrix(cat(libname[1],"/RadiationLengthTable.txt"),source=delimited,\
                       datatype=anything,delimiter="\t"); # works too

(I made the file using downloaded data).

I then want to fill the radiationlength properties for all elements for which I've got the value:

for i from 1 to LinearAlgebra:-RowDimension(data) do
  elemt:=data[i,1]; # the element name as a string
  ScientificConstants:-ModifyElement(cat(elemt),radiationlength=[value=data[i,4],units=g/cm^2]);
end do;

which fails with the error

Error, (in ScientificConstants:-ModifyElement) element ``H `` is not known

H is the first element in the table of radiation lengths so it is getting the right one.

At  issue is that somehow the element name (called descriptor in the Help files) does not seem to get properly evaluated. In fact I tried various ways "by hand", none except just the unevaluated element name (i.e H,He etc. worked).

There must be a way to set these in a loop. Does someone know how?

TIA,

Mac Dude

 

 

help me

into

 

Why I could not unaasign U_hat in my following program?


 

``

restart

II := 1:

qq := 2:

M := 2:

seq(seq(seq(assign(U[i, j, m], h*`#mover(mi("U"),mo("&uminus0;"))`[i, j, m]), i = 0 .. qq), j = 0 .. qq), m = 1 .. 22)

`#mover(mi("U"),mo("&uminus0;"))` := Array(0 .. II, 0 .. JJ, 1 .. M):

Um[1, 1] := Matrix(2, 2, {(1, 1) = 1, (1, 2) = 2, (2, 1) = 3, (2, 2) = 4}); Um[1, 2] := Matrix(2, 2, {(1, 1) = 5, (1, 2) = 6, (2, 1) = 7, (2, 2) = 8})

``

for m to M do `#mover(mi("U"),mo("&uminus0;"))`[0 .. II, 0 .. JJ, m] := ArrayTools:-Alias(Um[1, m], [0 .. II, 0 .. JJ]) end do:

``

for i from 0 to qq do for j from 0 to qq do for m to 22 do `#mover(mi("U"),mo("&uminus0;"))`[i, j, m] := unassign('`#mover(mi("U"),mo("&uminus0;"))`[i, j, m]') end do end do end do

Error, (in unassign/indexed) arguments of type `indexed' must refer to tables or arrays

 

``


 

Download moshkel.mw

Here is a simple little procedure that does not work

et :=proc(x) 

description   "this is a variant of evalf that gets rid of almost 0 nos.(rounding error) and shortens the display to 2 `digits"`;  

if  abs(x) < 10^((-14))  then 0 else  evalf(x,2) end if     end proc;


Error, unable to delimit strings/identifiers


and here is the same procedure that works because I added the # before the description.

et :=proc(x)

# description   "this is a variant of evalf that gets rid of almost 0 nos.(rounding error) and shortens the display to 2 `digits"`;  

if  abs(x) < 10^((-14))  then 0 else  evalf(x,2) end if     end proc;

 

In the help pages they do not say that the description must be hidden by the # sign (nor do they mention that quotes should be used although they are used in the examples.

 

What am I missing?

 

 

 

How can I activate my maple 13?

I have no activatIon left but installed maple

once

My purchase Code is BNN7VMT4BPFN7ESG

Thank. You 

Hi,

Is there any one can tell me how to plot a curve(e.g f(x,1)=2x^2-x-1) by the command spacecurve?

Thanks in advance!

Hello,

Attached is my code where the output of interest is the variable X. What I am trying to do is replace anywhere in this expression that I see "sqrt((nx^2+ny^2+nz^2)c^2) by the variable phi in order to make the expression easier to look at and interpret. This should be a relatively easy thing to accomplish, however I have had problems with doing this. Ive tried using algsubs etc. but nothing seems to work. Could anyone show me how to do this? Is there an easy method that works for doing this for similar problems in the future? I have run across this problem before so I would love to know how to solve it for the future. Thanks in advance.

Also pretty new to maple so thanks for your patience.

 

 

I would like to compute the function 

                       f(x) := exp(x) * HeunC(2*x, 1/2, -1/2, -x^2, 1/8, 99/100)

for very large real values of x. However, in the following plot it can be seen that there are already strong numerical instabilities for x>33. What can I do to reach more stability for large x? Or, does somebody know how to get a closed form asymptotic expression for large x?

 

I am working on a simple set of notes for students. Much of the on-line stuff is either out-of-date or too complex.

Here is the problem I wish to show

A corpse was found in a room with an ambient temperature of 64°F. The body temperature on finding the corpse was 75°F; one hour later it was 73°F. Use Newtons Law of cooling to find the time of death.

Here is my solution. I realise the assignment to variable cool is not used. Please tell me any suggestions for improvements.

many thanks


Hi,


When you do this a := plot(1/x, x=0..1);  the figure contains a "smart" graph which extends roughly from 0 to 30 in the vertical direction.
(no discont=true nor smartview=false used here, numpoints set to its default falue)

If you use plottools:-getdata(a); you find that the vertical range is about  0..1800.
It seems to mean that smartview=true (the default setting) overrides the range determined from the values of discont and numpoints?
 

My question is: Is it possible to retrieve the vertical range that plot uses when it displays the graph?
 

Dear all,

I need your help to compute the multiplicative  group generated by the following two matrices.

A :=  Matrix(2, 2, [[2, 0], [0, 1]]) ;

B := Matrix(2, 2, [[1, 1], [0, 1]]) ;

 such that A.B different to B.A

many thanks

 

Hello Dr/Pof/Colleague

Please help me on the ODE BVP problem

my target i want RUN double loop


 

restart

with(plots)

b := 0; c := 0; k[1] := 1; k[2] := 0; Un := 0; d := 0

Eq1 := (101-100*lambda)*(1+a*phi(eta))*(diff(f(eta), `$`(eta, 3)))+(diff(f(eta), `$`(eta, 2)))*(f(eta)+g(eta)+a*(diff(phi(eta), eta)))-(diff(f(eta), eta))^2+k[2]+Un*(k[2]-(1/2)*eta*(diff(f(eta), `$`(eta, 2)))-(diff(f(eta), eta))) = 0

(101-100*lambda)*(1+a*phi(eta))*(diff(diff(diff(f(eta), eta), eta), eta))+(diff(diff(f(eta), eta), eta))*(f(eta)+g(eta)+a*(diff(phi(eta), eta)))-(diff(f(eta), eta))^2 = 0

(1)

Eq2 := (101-100*lambda)*(1+a*phi(eta))*(diff(g(eta), `$`(eta, 3)))+(diff(g(eta), `$`(eta, 2)))*(f(eta)+g(eta)+a*(diff(phi(eta), eta)))-(diff(g(eta), eta))^2+k[2]+Un*(k[2]-(1/2)*eta*(diff(g(eta), `$`(eta, 2)))-(diff(g(eta), eta))) = 0

(101-100*lambda)*(1+a*phi(eta))*(diff(diff(diff(g(eta), eta), eta), eta))+(diff(diff(g(eta), eta), eta))*(f(eta)+g(eta)+a*(diff(phi(eta), eta)))-(diff(g(eta), eta))^2 = 0

(2)

NULL

Valpha := [0, .1, .2]; Va := [0, 0]

etainf := 100

bcs := (D(f))(0) = k[1], (D(g))(0) = alpha, f(0) = 0, g(0) = 0, (D(f))(etainf) = k[2], (D(g))(etainf) = k[2]

(D(f))(0) = 1, (D(g))(0) = alpha, f(0) = 0, g(0) = 0, (D(f))(100) = 0, (D(g))(100) = 0

(3)

dsys := {Eq1, Eq2, bcs}

for j to 2 do for i to 3 do a := Va[j]; alpha := Valpha[i]; dsol[j][i] := dsolve(dsys, numeric, continuation = lambda); print(alpha); print(a); print(dsol[j][i](0)) end do end do

Error, incorrect number of arguments to _Inert_FORFROM

"for j from 1 to 2 do   for i from 1 to 3 do a:=Va[j]; alpha:=Valpha[i];  dsol[j][i]:=dsolve(dsys,numeric, continuation=lambda);  print(alpha);    print(a);  print(dsol[j][i](0));  od  end"

 

NULL

 


 

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