MaplePrimes Questions

0.733333e^-1

0.733333e^-3

0.733333e^-5

0.733333e^-7

 

no matter what e is , expect to output the same 0.733333

 

I am trying to plot y:=x^2+x-12 as a curve and as a series of point. It is just not working. Suggestions, please.

Digitalize.mw
 

restart

f := proc (x) options operator, arrow; x^2+x-12 end proc

n := 10

h := 5``

printf("\n    i        x       f (dec.form)    f (sci. notat.)\n"); printf("  ---------------------------------------------------\n"); for i from 0 to n do X[i] := i*h; Y[i] := f(X[i]); printf(" %5d  %9.4f  %13.9f  %17.10e\n", i, X[i], Y[i], Y[i]) end do


    i        x       f (dec.form)    f (sci. notat.)
  ---------------------------------------------------
     0     0.0000  -12.000000000  -1.2000000000e+01
     1     5.0000   18.000000000   1.8000000000e+01
     2    10.0000   98.000000000   9.8000000000e+01
     3    15.0000  228.000000000   2.2800000000e+02
     4    20.0000  408.000000000   4.0800000000e+02
     5    25.0000  638.000000000   6.3800000000e+02
     6    30.0000  918.000000000   9.1800000000e+02
     7    35.0000  1248.000000000   1.2480000000e+03
     8    40.0000  1628.000000000   1.6280000000e+03
     9    45.0000  2058.000000000   2.0580000000e+03
    10    50.0000  2538.000000000   2.5380000000e+03

 

``

plot1 := plot([X[k], Y[k]], k = 0 .. n, style = point, symbol = soliddiamond, symbolsize = 24, color = blue)

plot2 := plot(f(x), x = 0 .. 50)

with(plots)

display([plot1, plot2])

 

``


 

Download Digitalize.mw

 

 

restart;

with(IntegrationTools):

# A very simple double integral

J:=Int(Int(x^2, x = 0 .. y), y = 0 .. 1);

Int(Int(x^2, x = 0 .. y), y = 0 .. 1)

(1)

value(J);

1/12

(2)

# Try a simple change of variables

Change(J, x=t*y, [t]);   # Why this form?

Intat(Intat(_a^2, _a = _b)-Intat(_a^2, _a = 0), _b = 1)-Intat(Intat(_a^2, _a = _b)-Intat(_a^2, _a = 0), _b = 0)

(3)

value(%);

1/12

(4)

# Now the same for 2*J

Change(2*J, x=t*y, [t]);  # OK, but why?

2*(Int(y^3*(Int(t^2, t = 0 .. 1)), y = 0 .. 1))

(5)

value(%);

1/6

(6)

 


Download IntegrationTools-Change.mw

Am trying to analyse a set of strings.   Can anyone help?

We have 10 x10 matrix into which we need to add connection score.
ExY := [WPKCPYWFYWCXHY, WPKCTEYFHCFEEE, HYCYTFHYYWWKCE, HYHHTFHKFEYHEH, HKXWYHFECTFFTF, HKWEHPPECWWHTC, HKXWYTPXHFHWYP, HKFEXCTFECXFKP, HKFEYPPEEEPHYW, HYTHCCFEWPPEXX, HKXKXCKFCHTEWK, HYEKPPCKFTWXXW];
Here is the code to create the connection matrix 
A__c = A__a+A__d;
.
Blist:=[W,P,K,C,Y,F,X,H,T,E]:# basis letters
nWords:=numelems(ExY):Wletters:=length(ExY[1]):Bletters:=numelems(Blist):A:=Matrix(Bletters,Bletters):# set up dimensions
for iW from 1 to nWords do  # loop through words
  for iL from 1 to Wletters-1 do # loop through letters of each word
     fromLett:=C(iW,iL); # see char extraction from ExY list above 
     toLett:=C(iW,iL+1); # ditto
     BfromLett:=Search(fromLett,Blist);# column id   <<<<<< the search is returning 0, it works if one uses "A" rather than say fromLett=A 
     BtoLett:=Search(toLett,Blist);# row id   <<<<<  ditto here
     A(BfromLett,BtoLett):=A(BfromLett,BtoLett)+ 1; # add statistic to the A-matrix
  end do; # end letter loop
end do; # end word loop
Error, index out of bounds
The search function is failing: 
Blist; Wletters; Bletters; nWords; fromLett; toLett; BfromLett; BtoLett; A; iW; iL;
                 [W, P, K, C, Y, F, X, H, T, E]
                               14
                               10
                               12
                              "W"
                              "P"
                               0
                               0

                 [0  0  0  0  0  0  0  0  0  0]
                 [                            ]
                 [0  0  0  0  0  0  0  0  0  0]
                 [                            ]
                 [0  0  0  0  0  0  0  0  0  0]
                 [                            ]
                 [0  0  0  0  0  0  0  0  0  0]
                 [                            ]
                 [0  0  0  0  0  0  0  0  0  0]
                 [                            ]
                 [0  0  0  0  0  0  0  0  0  0]
                 [                            ]
                 [0  0  0  0  0  0  0  0  0  0]
                 [                            ]
                 [0  0  0  0  0  0  0  0  0  0]
                 [                            ]
                 [0  0  0  0  0  0  0  0  0  0]
                 [                            ]
                 [0  0  0  0  0  0  0  0  0  0]
 

Hello

I found this paper. 

http://benson-labs.com/uploads/stuff/POW15.pdf

I'm not sure if the population after 1 year is correct.

I wanted to get the formula from rsolve. But i have incorrorectly formulated the sum by day and the total.

Rattus_recursion.mw

 

Whilst trying to debug another problem on this site, this one

https://www.mapleprimes.com/questions/225688-How-To-Compute-Inverse-Of-A-Matrix-For

I came across a Maple bug(?) which was so serious, I thought either

  1. I'm being more than usually dim
  2. it needs it's own entry here, so that others can check

Problem can be summarized as:

When using 2D input, can the '.' character be used for simple matrix multiplication???? Because it isn't working for me!

Entering the '.' character places a bold, midline dot between the two arguments, but executing the result gives "Error unable to parse". Converting to 1-D input, no issues - everything works as expected.I should also point out that

  1. I never normally use 2D-input for my own work
  2. the attached worksheet executes correctly in Maple 2017.3, X86 64 WINDOWS, Sep 13 2017, Build ID 1262472.

If this is reproducible then wtf!

restart; with(LinearAlgebra); kernelopts(version)

`Maple 2018.1, X86 64 WINDOWS, Jun 8 2018, Build ID 1321769`

(1)

A := RandomMatrix(2, 2); B := RandomMatrix(2, 2)

Matrix(2, 2, {(1, 1) = 44, (1, 2) = -31, (2, 1) = 92, (2, 2) = 67})

 

Matrix(%id = 18446744074378134462)

(2)

A.B

Error, unable to parse

"A*B;"

 

LinearAlgebra:-Multiply(A, B)

Matrix(%id = 18446744074378136502)

(3)

A:= RandomMatrix(2, 2);
B:= RandomMatrix(2, 2);
A.B

Matrix(2, 2, {(1, 1) = -32, (1, 2) = -4, (2, 1) = -74, (2, 2) = 27})

 

Matrix(2, 2, {(1, 1) = -93, (1, 2) = -72, (2, 1) = -76, (2, 2) = -2})

 

Matrix(%id = 18446744074378132406)

(4)

 

Download matMulProb.mw

I'm start making an homepage about mathematic and wondt to link a workpage writen in Maple 16 into WP, thanks to whose ho have any idea :)

 

Hello,

I have a set of nonlinear equations (transcendental) containing variables and one free parameter. I want to solve this system for variables while varying parameter's value. I have tried with fsolve and solve commands keeping fixed the parameter value, but they are not solving yet. Is there any way to solve this system for a range of parameter's value.
The systmem is like this, x,y,z are the variables and 'a' is the parameter:
f1(x,y,z,a)=0,
f2(x,y,z,a)=0,
f3(x,y,z,a)=0.

Many thanks in advance.

Hi,

I submit you this strange result:
for somenumerical  values of a, b, c  (a, b, c real and b > a), Maple 2018 is not able to compute the mean of
c*U where U is a Uniform random variable with support [a, b].


 

restart:

with(Statistics):

interface(version);

`Standard Worksheet Interface, Maple 2018.0, Windows 7, March 10 2018 Build ID 1298750`

(1)

z := .4070716688*RandomVariable(Uniform(0.12-0.02*0.12, 0.12+0.02*0.12));
Mean(z);

.4070716688*_R

 

Error, (in Statistics:-Mean) the expression does not have a taylor expansion at t = 0

 

z := .4070716688*RandomVariable(Uniform(a, b));
Mean(z);
subs({a=0.12-0.02*0.12, b=0.12+0.02*0.12}, %);

.4070716688*_R0

 

.2035358344*a+.2035358344*b

 

0.4884860026e-1

(2)

 


 

Download Mean.mw


PLEASE: Maple still fails if I replace  a = 0.12 -0.02*0.12 by its value 0.1174
                                                                       and b = 0.12+0.02*0.12 by its value 0.1224
                   

This is incomprehensible and could hide a more profound problem.

Good day everyone,

I am trying to write HAM code for coupled ODE but getting errors like "table(...)" or

 

"Error, (in dsolve) found the independent variables {eta} also present in the names of the functions of the system {(diff(diff(diff((table( [( 0 ) = proc (eta) options operator, arrow, function_assign; eta*exp(-eta)-F[w] end proc ] ))(eta), eta), eta), eta))(f[1](eta)), (diff(diff((table( [( 0 ) = proc (eta) options operator, arrow, function_assign; exp(-eta) end proc ] ))(eta), eta), eta))(theta[1](eta)), (diff((table( [( 0 ) = proc (eta) options operator, arrow, function_assign; eta*exp(-eta)-F[w] end proc ] ))(eta), eta))(f[1](eta)), ((table( [( 0 ) = proc (eta) options operator, arrow, function_assign; exp(-eta) end proc ] ))(eta))(theta[1](eta))}"

 

Anyone with useful informations should please help.

Thank you.

Below is the attached of the file

untitled22222.m

Does Maple have a way to upload a screenshot of a worksheet or a savefile of a worksheet to MaplePrimes?

Hi.

How I can Plot voltage (v) versus time (t) in nonlinear differential equation.

if possible please provide a simple example for me. for instance the command that I must use!!

plot.pdf

Hello everyone, i've a problem working with Maple because i have a really big system of equations and for everything that i have to do with them, for example, collect terms, coefficients, take a lot of time from me. The problem it is when, for example, i wait 30 minutes to take the coefficients from a equation and in the next command Maple might stop, then i have to close and start all over again... My question it is if have anyway to save my file in a way that if i close and re open i dont have to compile all again. Maybe this is pretty obvious but i really dont know how to do it, because if i close my work and open again, i have to compile everything again.

Following creates a list of 10 numbers 1..10:

  L := []; for i from 1 to 10 do L := [op(L), i] end do;

Now suppose I have equations labelled (1) ... (10). Can I place these equations into a list by some analogy of the above code using the label references?

 

 

Y = (-2*k^3+6*k^2+sqrt(k^8-12*k^7+64*k^6-198*k^5+448*k^4-636*k^3+369*k^2)-7*k-15)/((k^3-3*k^2+5*k-15)*(1+k))

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