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How to generate random elements of matrix ...

Asked by: jalal 380
matrix random
November 07 2020
0  12

Hi, how to generate a matrix ( 6X2) with different random integers  ( between 10 and 20) in the first column and others random integers ( between 50 and 100) in the second column ?

Thanks

SérieTabulateStat.mw

Workbook / access to other worksheets?...

Asked by: Anthrazit 750
embedded-components workbook
November 07 2020
0  1

Is it possible in one worksheet of a workbooks to access variables or embedded components in another worksheet programmatically?

As far as I can see it is possible to save and restore variables through the variable browser, so it is also possible to get them from one worksheet to another. This is however done by the user.

Now the question is, if it is somehow possible to e.g. access the contents of a embedded component like a Combobox in a different worksheet of the workbook - without opening the worksheet first?

How to sort and group by list of lists...

Asked by: ComputerUser 535
sort list
November 07 2020
0  0

[[1,1,["ab","xy"]], [0,1,["xy"]]]
 

how to sort by first number , second number , and list of string ?

how to count and group by third list of strings having first two number 0,0 or 0,1 or 1,0 or 1,1 

for example 

["xy"] at most count 4  , at least count 1

would like to find which is [1,1,... ] and only count 1

 

How to implement Prüfer's algorithm in Maple?...

Asked by: DJJerome1976 535
algorithm tree
November 06 2020
1  15

Is Prüfer's algorithm available in Maple (given a tree, produce the code, and vice versa)? If not, has anyone written the code for it?

How to compare solutions of a polynomial system?...

Asked by: emendes 395
polynomial simplification
November 06 2020
1  10

Hello

I need to check if the solution of a polynomial system (for instance a set of polynomial equations in y and z) using two different approaches is the same (equal or symmetric).  I thought if I use simplify plus abs I could solve the problem, but that is not the case.   Here is an example;

The first method returns the following solution:

aa := {{y = -2*X1*X2*alpha[1, 8]*alpha[2, 6]/(sqrt((X1^4*alpha[1, 8]^2*alpha[2, 4]^2 + 2*X1*((-2*X1*X2*alpha[3, 6] - 2*X2*alpha[2, 2] + 2*X3)*alpha[2, 6] + X1*X2*alpha[2, 4]*(alpha[2, 8] + alpha[3, 9]))*alpha[1, 8] + X2^2*(alpha[2, 8] + alpha[3, 9])^2)*alpha[1, 8]^2) + alpha[1, 8]^2*alpha[2, 4]*X1^2 + X2*alpha[1, 8]*(alpha[2, 8] + alpha[3, 9])), z = (-sqrt((X1^4*alpha[1, 8]^2*alpha[2, 4]^2 + 2*X1*((-2*X1*X2*alpha[3, 6] - 2*X2*alpha[2, 2] + 2*X3)*alpha[2, 6] + X1*X2*alpha[2, 4]*(alpha[2, 8] + alpha[3, 9]))*alpha[1, 8] + X2^2*(alpha[2, 8] + alpha[3, 9])^2)*alpha[1, 8]^2) - alpha[1, 8]^2*alpha[2, 4]*X1^2 + (-alpha[3, 9] - alpha[2, 8])*X2*alpha[1, 8])/(2*alpha[1, 8]^2*alpha[2, 6]*X1)}, {y = -2*X2*alpha[1, 8]*alpha[2, 6]*X1/(-sqrt((X1^4*alpha[1, 8]^2*alpha[2, 4]^2 + 2*X1*((-2*X1*X2*alpha[3, 6] - 2*X2*alpha[2, 2] + 2*X3)*alpha[2, 6] + X1*X2*alpha[2, 4]*(alpha[2, 8] + alpha[3, 9]))*alpha[1, 8] + X2^2*(alpha[2, 8] + alpha[3, 9])^2)*alpha[1, 8]^2) + alpha[1, 8]^2*alpha[2, 4]*X1^2 + X2*alpha[1, 8]*(alpha[2, 8] + alpha[3, 9])), z = (sqrt((X1^4*alpha[1, 8]^2*alpha[2, 4]^2 + 2*X1*((-2*X1*X2*alpha[3, 6] - 2*X2*alpha[2, 2] + 2*X3)*alpha[2, 6] + X1*X2*alpha[2, 4]*(alpha[2, 8] + alpha[3, 9]))*alpha[1, 8] + X2^2*(alpha[2, 8] + alpha[3, 9])^2)*alpha[1, 8]^2) - alpha[1, 8]^2*alpha[2, 4]*X1^2 + (-alpha[3, 9] - alpha[2, 8])*X2*alpha[1, 8])/(2*alpha[1, 8]^2*alpha[2, 6]*X1)}}

and the second Method:

bb := {{y = -2*X2*alpha[2, 6]*X1/(-sqrt(X1^4*alpha[1, 8]^2*alpha[2, 4]^2 + 2*X2*alpha[1, 8]*((alpha[2, 8] + alpha[3, 9])*alpha[2, 4] - 2*alpha[2, 6]*alpha[3, 6])*X1^2 - 4*alpha[1, 8]*alpha[2, 6]*(X2*alpha[2, 2] - X3)*X1 + X2^2*(alpha[2, 8] + alpha[3, 9])^2) + (alpha[2, 8] + alpha[3, 9])*X2 + alpha[1, 8]*alpha[2, 4]*X1^2), z = (sqrt(X1^4*alpha[1, 8]^2*alpha[2, 4]^2 + 2*X2*alpha[1, 8]*((alpha[2, 8] + alpha[3, 9])*alpha[2, 4] - 2*alpha[2, 6]*alpha[3, 6])*X1^2 - 4*alpha[1, 8]*alpha[2, 6]*(X2*alpha[2, 2] - X3)*X1 + X2^2*(alpha[2, 8] + alpha[3, 9])^2) - alpha[1, 8]*alpha[2, 4]*X1^2 + (-alpha[3, 9] - alpha[2, 8])*X2)/(2*alpha[1, 8]*alpha[2, 6]*X1)}, {y = -2*X2*alpha[2, 6]*X1/(sqrt(X1^4*alpha[1, 8]^2*alpha[2, 4]^2 + 2*X2*alpha[1, 8]*((alpha[2, 8] + alpha[3, 9])*alpha[2, 4] - 2*alpha[2, 6]*alpha[3, 6])*X1^2 - 4*alpha[1, 8]*alpha[2, 6]*(X2*alpha[2, 2] - X3)*X1 + X2^2*(alpha[2, 8] + alpha[3, 9])^2) + alpha[1, 8]*alpha[2, 4]*X1^2 + (alpha[2, 8] + alpha[3, 9])*X2), z = (-sqrt(X1^4*alpha[1, 8]^2*alpha[2, 4]^2 + 2*X2*alpha[1, 8]*((alpha[2, 8] + alpha[3, 9])*alpha[2, 4] - 2*alpha[2, 6]*alpha[3, 6])*X1^2 - 4*alpha[1, 8]*alpha[2, 6]*(X2*alpha[2, 2] - X3)*X1 + X2^2*(alpha[2, 8] + alpha[3, 9])^2) - alpha[1, 8]*alpha[2, 4]*X1^2 + (-alpha[3, 9] - alpha[2, 8])*X2)/(2*alpha[1, 8]*alpha[2, 6]*X1)}}

Notice (if I am not mistaken) that the first pair of the first solution is equal to the second pair of the second solution.   If I compare them using evalb(simplify(aa[1,1])=simplify(bb[2,1])), Maple returns false.  Again, if I am not mistaken I think they are the same.

a) How can the solutions be compared?

b) I also need to determine if there are symmetric roots in a set of solutions (either in aa or in bb) and a procedure that returns just one solution.  Something like:

func:=(auxsolsx,varsx)->`if`(nops(map(v->op(map(w->abs(subs(w[ListTools:-Search(v,varsx)],v)),auxsolsx)),varsx))=2,ifelse(nops(auxsolsx)=1,auxsolsx,{auxsolsx[1]}),NULL):

Many thanks

 

 

 

Typset in the seq command ?...

Asked by: jalal 380
typesetting plotting title
November 06 2020
1  3

Hi,

I try to represent the successive derivatives of a function using a tabulation . How do I insert titles in the seq command options?

Thanks

QuestionTabulation.mw

A digression about the US electoral college tie

by: mmcdara 6149 Maple 2015
statistics listtools randperm
November 06 2020
2  2

A fascinating race is presently running (even if the latest results seem  to have put an end to it).
I'm talking of course about the US presidential elections.

My purpose is not to do politics but to discuss of a point of detail that really left me puzzled: the possibility of an electoral college tie.
I guess that this possibility seems as an aberration for a lot of people living in democratic countries. Just because almost everywhere at World electoral colleges contain an odd number of members to avoid such a situation!

So strange a situation that I did a few things to pass the time (of course with the earphones on the head so I don't miss a thing).
This is done with Maple 2015 and I believe that the amazing Iterator package (that I can't use thanks to the teleworking :-( ) could be used to do much more interesting things.

 

> 

restart:
> 

with(Statistics):
> 

ElectoralCollege := Matrix(51, 2, [
> 

Alabama,        9,        Kentucky,        8,        North_Dakota,        3,
> 

Alaska,        3,        Louisiana,        8,        Ohio,        18,
> 

Arizona,        11,        Maine,        4,        Oklahoma,        7,
> 

Arkansas,        6,        Maryland,        10,        Oregon,        7,
> 

California,        55,        Massachusetts,        11,        Pennsylvania,        20,
> 

Colorado,        9,        Michigan,        16,        Rhode_Island,        4,
> 

Connecticut,        7,        Minnesota,        10,        South_Carolina,        9,
> 

Delaware,        3,        Mississippi,        6,        South_Dakota,        3,
> 

District_of_Columbia,        3,        Missouri,        10,        Tennessee,        11,
> 

Florida,        29,        Montana,        3,        Texas,        38,
> 

Georgia,        16,        Nebraska,        5,        Utah,        6,
> 

Hawaii,        4,        Nevada,        6,        Vermont,        3,
> 

Idaho,        4,        New_Hampshire,        4,        Virginia,        13,
> 

Illinois,        20,        New_Jersey,        14,        Washington,        12,
> 

Indiana,        11,        New_Mexico,        5,        West_Virginia,        5,
> 

Iowa,        6,        New_York,        29,        Wisconsin,        10,
> 

Kansas,        6,        North_Carolina,        15,        Wyoming,        3
]):
 

ElectoralCollege := Vector(4, {(1) = ` 51 x 2 `*Matrix, (2) = `Data Type: `*anything, (3) = `Storage: `*rectangular, (4) = `Order: `*Fortran_order})

 (1)
> 

add(ElectoralCollege[..,2]):
tie := %/2;

269

 (2)
> 

ec := convert(ElectoralCollege, listlist):
> 

# Sets of states that form an electoral college tie

R      := 10^5:
nbties := 0:
states := NULL:
for r from 1 to R do
  poll  := combinat:-randperm(ec):
  cpoll := CumulativeSum(op~(2, poll)):
  if tie in cpoll then
    nbties := nbties+1;
    place  := ListTools:-Search(tie, cpoll);
    states := states, op~(1, poll)[1..place]:   # see below
  end if:
end do:
> 

# electoral college tie is not so rare an event
# (prob of occurrence about 9.4 %).
#
# Why the hell the US constitution did not decide to have an odd
# number or electors to avoid ths kind of situation instead of
# introducing a complex mechanism when tie appears????

nbties;
evalf(nbties/R);

states := [states]:

9397

  

0.9397000000e-1

 (3)
> 

# What states participate to the tie?

names := sort(ElectoralCollege[..,1]):

all_states_in_ties := [op(op~(states))]:

howoften := Vector(
                    51,
                    i -> ListTools:-Occurrences(names[i], all_states_in_ties)
            ):

ScatterPlot(Vector(51, i->i), howoften);

 
> 

# All the states seem to appear equally likely in an electoral college tie.
# Why? Does someone have a guess?
#
# The reason is obvious, as each state must appear in the basket of a candidate,
# then in case of a tie each state is either in op~(1, poll)[1..place] (candidate 1)
# or either in op~(1, poll)[place+1..51] (candidate 2);
# So, as we obtained 9397 ties, each states appears exactly 9397 times (with
# different occurences in the baskets of candidate 1 and 2).

 
> 

# Lengths of the configurations that lead to a tie.
#
# Pleas refer to the answer above to understand why Histogram(lengths) should be
# symmetric.
lengths := map(i -> numelems(states[i]), [$1..nbties]):
sort(Tally(lengths))

[14 = 1, 15 = 2, 16 = 7, 17 = 36, 18 = 78, 19 = 179, 20 = 341, 21 = 507, 22 = 652, 23 = 849, 24 = 1015, 25 = 1041, 26 = 1056, 27 = 997, 28 = 862, 29 = 657, 30 = 515, 31 = 300, 32 = 158, 33 = 95, 34 = 41, 35 = 6, 36 = 2]

 (4)
> 

Histogram(lengths, range=min(lengths)..max(lengths), discrete=true)

 
> 

ShortestConfigurations := map(i -> if lengths[i]=min(lengths) then states[i] end if, [$1..nbties]):
print~(ShortestConfigurations):

[New_York, Wisconsin, Illinois, Kentucky, Florida, New_Jersey, Mississippi, Indiana, Virginia, Maryland, California, Massachusetts, North_Carolina, Texas]

 (5)
> 

LargestConfigurations := map(i -> if lengths[i]=max(lengths) then states[i] end if, [$1..nbties]):
print~(LargestConfigurations):

[Alaska, Tennessee, North_Carolina, South_Carolina, District_of_Columbia, Colorado, Minnesota, Georgia, South_Dakota, New_Hampshire, Wyoming, Ohio, Rhode_Island, Arizona, Delaware, Montana, West_Virginia, Vermont, Michigan, Kentucky, Louisiana, Arkansas, Maine, Missouri, New_Mexico, Virginia, Maryland, Oregon, Wisconsin, Iowa, Kansas, Connecticut, North_Dakota, Nevada, Hawaii, Oklahoma]

  

[West_Virginia, Maryland, Massachusetts, Colorado, South_Dakota, Kentucky, Kansas, Wyoming, North_Dakota, Indiana, Michigan, Utah, Louisiana, Ohio, Alabama, Nebraska, Connecticut, Illinois, Oklahoma, Alaska, New_Jersey, District_of_Columbia, Oregon, Nevada, Missouri, Delaware, Washington, New_Hampshire, Arizona, Maine, South_Carolina, Hawaii, Vermont, Montana, Rhode_Island, Idaho]

 (6)
> 

# What could be the largest composition of a basket in case of a tie?
# (shortest composition is the complementary of the largest one)

ecs   := sort(ec, key=(x-> x[2]));
csecs := CumulativeSum(op~(2, ecs)):

# Where would the break locate?

tieloc := ListTools:-BinaryPlace(csecs, tie);

csecs[tieloc..tieloc+1]

[[North_Dakota, 3], [Alaska, 3], [Delaware, 3], [South_Dakota, 3], [District_of_Columbia, 3], [Montana, 3], [Vermont, 3], [Wyoming, 3], [Maine, 4], [Rhode_Island, 4], [Hawaii, 4], [Idaho, 4], [New_Hampshire, 4], [Nebraska, 5], [New_Mexico, 5], [West_Virginia, 5], [Arkansas, 6], [Mississippi, 6], [Utah, 6], [Nevada, 6], [Iowa, 6], [Kansas, 6], [Oklahoma, 7], [Oregon, 7], [Connecticut, 7], [Kentucky, 8], [Louisiana, 8], [Alabama, 9], [Colorado, 9], [South_Carolina, 9], [Maryland, 10], [Minnesota, 10], [Missouri, 10], [Wisconsin, 10], [Arizona, 11], [Massachusetts, 11], [Tennessee, 11], [Indiana, 11], [Washington, 12], [Virginia, 13], [New_Jersey, 14], [North_Carolina, 15], [Michigan, 16], [Georgia, 16], [Ohio, 18], [Pennsylvania, 20], [Illinois, 20], [Florida, 29], [New_York, 29], [Texas, 38], [California, 55]]

  

40

  

Array(%id = 18446744078888202358)

 (7)
> 

# This 40  states coniguration is not a tie.
#
# But list all the states in basket of candidate 1 and look to the 41th state (which is
# in the basket of candidate 2)

ecs[1..tieloc];
print():
ecs[tieloc+1]

[[North_Dakota, 3], [Alaska, 3], [Delaware, 3], [South_Dakota, 3], [District_of_Columbia, 3], [Montana, 3], [Vermont, 3], [Wyoming, 3], [Maine, 4], [Rhode_Island, 4], [Hawaii, 4], [Idaho, 4], [New_Hampshire, 4], [Nebraska, 5], [New_Mexico, 5], [West_Virginia, 5], [Arkansas, 6], [Mississippi, 6], [Utah, 6], [Nevada, 6], [Iowa, 6], [Kansas, 6], [Oklahoma, 7], [Oregon, 7], [Connecticut, 7], [Kentucky, 8], [Louisiana, 8], [Alabama, 9], [Colorado, 9], [South_Carolina, 9], [Maryland, 10], [Minnesota, 10], [Missouri, 10], [Wisconsin, 10], [Arizona, 11], [Massachusetts, 11], [Tennessee, 11], [Indiana, 11], [Washington, 12], [Virginia, 13]]

  

 

[New_Jersey, 14]

 (8)
> 

# It appears that exchanging Virginia and New_Jersey increases by 1 unit the college of candidate 1
# and produces a tie.

LargestBasketEver := [ ecs[1..tieloc-1][], ecs[tieloc+1] ];

add(op~(2, LargestBasketEver))

[[North_Dakota, 3], [Alaska, 3], [Delaware, 3], [South_Dakota, 3], [District_of_Columbia, 3], [Montana, 3], [Vermont, 3], [Wyoming, 3], [Maine, 4], [Rhode_Island, 4], [Hawaii, 4], [Idaho, 4], [New_Hampshire, 4], [Nebraska, 5], [New_Mexico, 5], [West_Virginia, 5], [Arkansas, 6], [Mississippi, 6], [Utah, 6], [Nevada, 6], [Iowa, 6], [Kansas, 6], [Oklahoma, 7], [Oregon, 7], [Connecticut, 7], [Kentucky, 8], [Louisiana, 8], [Alabama, 9], [Colorado, 9], [South_Carolina, 9], [Maryland, 10], [Minnesota, 10], [Missouri, 10], [Wisconsin, 10], [Arizona, 11], [Massachusetts, 11], [Tennessee, 11], [Indiana, 11], [Washington, 12], [New_Jersey, 14]]

  

269

 (9)
> 

# The largest electoral college tie contains 40 states (the shortest 11)


 

Download ElectoralCollegeTie.mw

Continue code on error...

Asked by: Anthrazit 750
exception error
November 06 2020
0  4

Apparently when raising an error exception, Maple stops further code.

Is there any possibility to just show a popup message, and then continue with the code after the message?

ErrorGoOn.mw

Maple DEplot question...

Asked by: dim____ 45
ode homework differential-equations
November 05 2020
0  2

How to determine populations y for which y ' = 0? 

Maple Newton's law of cooling ...

Asked by: dim____ 45
ode homework dsolve
November 05 2020
0  3

Have no idea about solving Newton's law of cooling in maple. 

Is anyone can help me? Thanks! 

A question about fsolve...

Asked by: grosman 15
fsolve plotting
November 05 2020
1  8

Hello!

I have a function, say f(x,y), and I want to solve for x for a range of values of y. The function is complicated, and thus, I gather I need to use fsolve to find the set of solutions numerically. I know how to use fsolve to find x for a given (single) value of y, but I have never used it to generate a list of x values given a range of y values. Then, I would l like to plot x as function of y, but I will leave that for later.

 

Thank you!

Maple some problem solving question...

Asked by: dim____ 45
ode homework differential-equations
November 05 2020
0  1

Suppose we have a 200-litre tank. Suppose 10 litres per minute of salt water (brine) flows into the tank at the top, it mixes perfectly with the contents of the tank, and 10 litres per minute of the mixture flows out of the tank at the bottom. Assume for simplicity that the salt water in the tank is stirred so that its concentration is uniform in the tank. Let S(t) be the amount of salt, in grams, in the tank at t time minutes. Suppose the salt water flowing into the tank has concentration 80 grams per litre.

Find the differential equation to model the change in S(t).

Assuming that at t = 0 time the concentration of salt in the tank is 10 grams per litre, solve the differential equation using Maple.

What is S(infinite)? That is, how much salt is in the tank after a long time?

Now graph S(t) for a suitable domain so we can see the function approaching the value S(infinite)

---------------------

Have some difficulty to understand the problem. I mean, such modelling problem rather than pure math computation.

Thank you so much!

How do I plot a set of curves and a second funct...

Asked by: Trebron 20
multiple plotting
November 05 2020
2  1

I have a set of curves  :   plot({seq((6*x-2*t)/x^2, t = 1 .. 3)}, x = -1 .. 5, y = -1 .. 6)

and   a function           :   plot(3/x, x = 0 .. 5, y = -1 .. 6).

How is the calling sequence to plot the set and the function in the same graph ?

Error on unknown proc name...

Asked by: Anthrazit 750
programming spelling
November 05 2020
0  10

Is there a way to get a feedback from Maple, if it doesn't find any corresponding proc: to a procedure call?

Right now it takes very much time to bugtrack issues where there might be a spelling error in a call.

See example.

ProcNameWrong.mw

trouble with solving system of equations, substitu...

Asked by: jrive 160
November 05 2020
1  6

Hello, I'm new to Maple, transitioning over from Mathematica.  I have a system of equations I'm trying to solve, but am trying to substitute values for some of the variables.  I don't think I'm doing it right, because I don't see the value in place of the variable when it echos the expression. Here are my equations, and how I'm trying to solve them:

wres := sqrt(C1+C2)/sqrt)C1*C2*L1)

vores := -C1/C2*vin

z3 = (C1^2 *R1- j*sqrt(C1*C2*L1*(C1+C2)))/C2^2

sys :={wres=13.56e6*2*pi, C1=C2, z3=40,abs(vores/vin)>=1}

solve(sys, {C1, C2, L1, R1})

 

(I apologize; I coulnd't figure out how to enter the Maple code here, directly).

 

When I try this, solve returns nothing.  I then try forcing R1 to be 2000, for ex.  I tried modifying sys to be

 

sys:={wres=13.56e6*2*pi, C1=C2, R1=2000,  z3=40,abs(vores/vin)>=1}, but this does't work.

then I tried, R1:=2000, exepcting to see R1 substituted with 2000 in the echo from sys, but it stills shows R1....

 

How do I do this?  

Also, how do I go about investigating why solve is having trouble solving a system of equations?

 

Thanks

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