## How to extract data from implicit function with a ...

Asked by:

I plotted number of functions y=y(x) with different parameter aa for given value of tau (see the code below)

restart;
R0:=gamma+2*ln(2)+Re(Psi(1/2+(1+I)*tanh((1+I)*x)/((tau+0.25e-1*a)*y)))+ln(y);
tau := 9.975;
with(plots);
implicitplot({seq(R0, a = 1 .. 50)}, x = 0 .. 5, y = 0 .. 1, numpoints = 1000);

Thanks in a advance.

## How to hide the commands in a quiz created with Ma...

Asked by:

Hi, I try to create quizes in Maple 2016, but I don't know how to hide the Maple commands. Is it possible?

I'd like my students to see only

when they access the quiz. Any help will be highly appreciated. Thank you.

## Plot points in a plot component...

Asked by:

I can not understand why the following statement works perfectly:
with (plots);
P1: = plot (f (x), x = xmin .. xmax, y = ymin .. ymax, color = "green");
P2: = plot (orddir, x = xmin .. xmax, y = ymin .. ymax, color = "blue");

Plots [display] (plottools [line] ([ascf, ymin], [ascf, 10]), color = red;
Plot ([5, y, y = 0 .. 10]);
P3: = implicit plot (x = ascf, x = xmin .. xmax, y = ymin .. ymax, color = red, linestyle = 3, thickness = 2);
P4: = plot (points, x = xmin .. xmax, y = ymin .. ymax, style = point, symbol = circle, symbolsize = 20, color = "black");
P5: = plot (h, x = xmin .. xmax, y = ymin .. ymax, color = "yellow");
Display ({p1, p2, p3, p4, p5}, axes = normal, scaling = unconstrained, title = "Parallel, vertice, focus, direction and axis of symmetry", gridlines = true);

While in the following
Points: = [F, V, A, B];
with (plots):
P1: = plot (f (x), x = xmin .. xmax, y = ymin .. ymax, color = "green");
P2: = plot (yd, x = xmin .. xmax, y = ymin .. ymax, color = "blue");
P3: = implicitplot (x = xv, x = xmin .. xmax, y = ymin .. ymax, color = red, linestyle = 3, thickness = 2);
P4: = plot (points, x = xmin .. xmax, y = ymin .. ymax, style = point, symbol = circle, symbolsize = 20, color = "black");

Do (% Plot0 = display ({p1, p2, p3, p4}, axes = normal, scaling = unconstrained, title = "Parallel, vertices, focus, direction and axis of symmetry", gridlines = true));

P4 does not print anything. In thanking you for the kind attention, I cordially greet you. Carmine Marotta ..

## TravelingSalesman - speed...

Asked by:

How is it possible that  GraphTheory:-TravelingSalesman
is much slower than a simple brute-force solution?

 > restart;
 > n:=10:
 > A:=Matrix(n, (i,j)->`if`(i=j,0,n*(n-i)^4+2*j+(n-i)^2+j^3)):A[1,2]:=100*n^3:A;
 (1)
 > with(GraphTheory):
 > G:=Graph(A);
 (2)
 > t:=time[real](): TravelingSalesman(G); 'time'=time[real]()-t;
 (3)
 > ############### brute-force #############
 > t:=time[real](): P:=Iterator:-Permute([seq(2..n)]): cmin:=infinity: ord:=<"none">: for  v in P do   f:=add(A[v[k],v[k+1]],k=1..n-2) + A[1,v[1]]+A[v[n-1],1];   if f
 (4)
 > # And for n=11 I had to interrupt TravelingSalesman; # brute-force still works for n=12.

Download TravelingSalesman-test.mw

## how to find unused local variables in a proc?...

Asked by:

Sometimes when one write a proc(), and later make changes, some of the earlier local variables could no longer used after the new edits.

In a small proc, it is easy to spot visually which ones are no longer needed and to remove them. But for a large proc() with many local variables, it is harder.

Does maple have a tool  to help one find which are the unused local declarations are not used? For example

foo:=proc(x)
local y,z:
x^2;
end proc;

I'd like maple to tell me that `y` and `z` are unused when I asked it to. (may be by highlighting or warning)

Mathematica has such a tool (and more) in its workbench editor which is very useful. does one need an external tool in Maple to do this?

## Minimum cost of a TRP...

Asked by:

Experts.

I'm trying to solve a Truck Routing Problem. I set in up in Maple and Excel, but I get a smaller minimum in the spreadsheet, than in Maple. Its like as if I havn't generated enough possible routes, even though i feel i've done an exaustive search. I realise the distance matrix violates the triangle inequality.  Any suggestions....

TRP_14x3.mw

## How to convert an imported data to Vector?...

Asked by:

A very big data was imported by me through

data := Import("http://fs3.fex.net/get/245716150875/11071260/data.txt");
"3.0994584798345
22.889020258043
....

26.082759642081
42.911810680717
6.4578968130322"

I need to convert it to Vector/Array. Now its type is "string":

whattype(data);
string

Here is my unsuccessful attempt:

convert(data,Vector);
Error, invalid input: `convert/Vector` expects its 1st argument, V, to be of type {Array, Matrix, Vector, array, sequential}, but received 3.0994584798345
22.889020258043
....

data.mw

## GlobalMaximum of a function with various constrain...

Asked by:

Hey. Sorry if this is the wrong place to post, as I'm new here. Anyways, I'm trying to find the global maximum of a function, directly via Maple Commands, I've found that Maximize, does a good job to some degree, but when faced with "harder" constraints such as x^2+y^2=>1 it fails (or atleast I do :) ). I know that in WolframAlpha you can write that following as an example:

Maximize[{(1-y^2)/(x^2), x^2 + y^2 <= 1,x>=1/2}, {x, y}]

http://www.wolframalpha.com/input/?i=Maximize%5B%7B(1-y%5E2)%2F(x%5E2),+x%5E2+%2B+y%5E2+%3C%3D+1,x%3E%3D1%2F2%7D,+%7Bx,+y%7D%5D

How would I do this in Maple? Any help would be more than welcome!! Thanks :D

## Simplified form of equation/function ...

Asked by:

I am new user of Maple, couldn’t find solution for my problem in the last two days therefore I would like to turn to your community with my question. I am trying to replicate the calculations from a study to be sure about my understanding of the topic.

I cannot simplify the final equation even though the variables with their values are given. A screenshot and the file are attached, that might make easier to understand my problem.

I know what the solution should be. I cannot simplify/replace the values in the equation to get a simpler form; [(D0 - d1c - R)/ 2d1)]+c

Thank you if you have the time to help.

Joint_Pricing_Sol_.maple

## how to calculate probability of matrix in this cas...

Asked by:
i count the number among group
but when the list a large such as over 1000 records, the count will be over 30,000
use which denominator to find probability?
is there any functions in maple for this case?

with(LinearAlgebra):
correlationlist1 := [[1,2,3],[1,3,5]....]:
PAB := Matrix(50):
for ii from 1 to nops(correlationlist) do
for jj from 1 to nops(correlationlist[ii]) do
for kk from 1 to nops(correlationlist) do
for qq from 1 to nops(correlationlist[kk]) do
if ii <> kk then
#print("scan=",correlationlist2[kk],"kk=",kk,"qq=",qq,"row=",correlationlist[ii][jj],"column=",correlationlist[kk][qq]):
PAB[correlationlist[ii][jj],correlationlist[kk][qq]] := PAB[correlationlist[ii][jj],correlationlist[kk][qq]] + 1: # group to group relations
end if:
od:
od:
od:
od:

## problem with higher order equations roots...

Asked by:

hey guys ,

i have problem to obtain roots for a higher order equation

thanks for your helppp.mw

## How to use statistics correlate function with a li...

Asked by:

If there is a list

[[1,2],[2,2],[3,3]...

how to use correlate function?

assume [1,2] and [2,1] count as 2

when find correlation between 1and 2

and how about

if [1,2] and [2,1] are different

first position as key

means 1 relate with 2 count as 1 case for 1 only

[2,1] count as 1 case for 2 only

## Solving equation with two reststricted variables...

Asked by:

How do I check if there are any solutions to this equation:
1/(u+v)^2+4*u*v-1=0
where both u and v are real numbers larger than 0.

## on what grounds do posts get deleted?...

Asked by:

on what grounds do posts get deleted from this website? like i just dont see the problem if its non offensive and math related to be honest it just seems a bit ridiculous to regulate content to that extent

## back on the horse of course...

Asked by:

Hi, my question is concerning a "summand counting function" i require ie suppose for the following input

of [a+b+c,a+b,a+b+c+d,a] mapping this function will produce the output [3,2,4,1]

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