## Switching off saving results when saving a workshe...

I have worksheet that generates very large matrices and it seems to save all results, so it requires large amount of RAM to load and storage to save it.

There used to be a pop-up prompt not to save the results of the worksheet - to save space, but that no longer occurs.  Can someone help me to switch on that prompt not to save results or otherwise prevent saving results, when I open the spreadsheet.  It maybe that I agreed not to be prompted again, but now I am regretting it!!

MRB

## Font size in workbook...

12pt type is difficult for me to read.  I would like to fix a workbook so that everything yet to appear will be in 18pt type, without my having to enlarge things one at a time.   (I am a new MAPLE user.)

## How to solve a system of ODEs first and then plot ...

Hello,

I am solving a large system of ODEs, using the following command,

> Sol := dsolve({seq(ode[j], j = 0 .. 21), seq(v[j](0) = 0, j = 1 .. 21), v[0](0) = 1}, [seq(v[j](t), j = 0 .. 21)]);

>

and then plot the quantities I want by something like

> plots:-odeplot(Sol, [t, v[3](t)+v[5](t)], t = 0 .. 1.5);

My problem is that, I do not know a priori which quantity I want to plot, and plotting using above method requires solving the ODEs each time separately, which takes a long time.

So I was curious if there is a scheme that I can solve my system for once and for all, and then plot any quantities that I would like to see.

## Large system of Equations Mod 2...

Hi i 2 questions. all pertaining to solving a systems of equations mod 2

First if i have a large set of equations, 11^3 equations in 11 unknowns and i want maple to give me ALL solutions mod 2 how can i do that? Maples msolve is loosing solutions.

Second suppose i want all unique solutions that say 6 of the variables can have but dont care what the solution to the other variables are as long as it is a solution.

mini example:

say x=1,y=1,z=1 is a solution as well as x=1,y=1,z=0, i just want to know about x=1,y=1.

## Plotting a big expression, results in an empty gra...

Hi all

I'm having a hard time, making Maple plot a pretty huge expression in my project.

I have solved a differential equation with initial conditions with method=laplace. The differential equation contains a fourier serie equation, so the more accurate i want the equation to be, the larger the differential equation will be.

Maple solves the equation just fine, and i can plot the solution with 2-4 fourier parts, but when i go higher as i need, the graph ends up empty?

with 20 parts i get the following equation:

0.*sin(52.88*t)+0.*cos(74.03*t)-0.*sin(74.03*t)-0.*cos(52.88*t)+0.*cos(200.95*t)-0.*sin(200.95*t)+0.*cos(158.65*t)-5.55*10^(-8)*sin(105.76*t)-0.*sin(116.34*t)+0.*cos(31.73*t)-.45*sin(10.58*t)+1.02*cos(10.58*t)+0.*sin(95.19*t)+0.*cos(116.34*t)+0.*sin(179.80*t)-0.*cos(179.80*t)+0.*sin(137.49*t)-0.*sin(31.73*t)-0.*cos(95.19*t)+5.53*10^(-993)*(-1.13*10^992*cos(10.61*t)+8.14*10^991*sin(10.61*t))*exp(-0.7e-1*t)+4.23*10^(-7)*cos(211.53*t)-6.69*10^(-7)*cos(63.46*t)-6.11*10^(-7)*cos(105.76*t)+5.79*10^(-7)*cos(126.92*t)+6.67*10^(-8)*sin(42.31*t)-5.88*10^(-8)*sin(148.07*t)+5.88*10^(-8)*sin(211.53*t)+7.09*10^(-7)*cos(42.31*t)+5.45*10^(-8)*sin(84.61*t)+6.40*10^(-7)*cos(84.61*t)+5.72*10^(-8)*sin(126.92*t)-9.01*10^(-7)*cos(21.15*t)+5.97*10^(-8)*sin(169.22*t)+5.06*10^(-7)*cos(169.22*t)-5.98*10^(-8)*sin(190.38*t)-4.65*10^(-7)*cos(190.38*t)-5.44*10^(-7)*cos(148.07*t)-1.33*10^(-7)*sin(21.15*t)-5.61*10^(-8)*sin(63.46*t)-0.*cos(137.49*t)-0.*sin(158.65*t)

if i plot that expression, the graph ends up empty?

I did also try to solve the equation numerical to plot it with odeplot, but when i try to solve it without the laplace method i get this error message:
"Error, (in dsolve) found the following equations not depending on the unknows of the input system:"

The differential equation is:

ode:=diff(Theta(t), t, t)+2*Zeta*omega[balanceue]*(diff(Theta(t), t))+omega[balanceue]^2*Theta(t) = M[p]/m[balanceue]

and the initial conditions:

ICS := Theta(0) = (1/8)*Pi, (D(Theta))(0) = 0;

when i do:

dsolve({ICS, ode}, Theta(t), method = laplace) it solves just fine.

but when i try with:

dsolve({ICS, ode}, Theta(t))

or

dsolve({ICS, ode}, Theta(t),numeric)

I get the message:

Error, (in dsolve) found the following equations not depending on the unknowns of the input system: {Theta(0) = (1/8)*Pi, (D(Theta))(0) = 0}

It doesnt seem logical at all, is it a bug? Or can anybody help me with this problem?

Regards

Nicolai

## Reducing the size of large pdf (due to figures) ex...

According to kernelopts(version), I am using Maple 16.02, X86 64 LINUX, Nov 18 2012, Build ID 7888210 , having just updated

Maple 16.

I have a Maple worksheet with some graphs of 10^5 data points. When I export the worksheet to a pdf for inclusion in a LaTeX document (with pdfpages package, this recognizes page breaks), the file is around 100 Mb, much larger than I would like.

It seems that the file is large as a figure in the pdf is not just an image, the pdf seems to contain all of the information necessary to plot each data point individually.

Is there some way to encourage Maple 16 to treat figures as bitmaps (or something similarly much smaller than the original figures) upon exporting a worksheet to a pdf? I'll be happy for any suggestions.

NOTES:

1. This question was originally for Maple 16.00. Updating to 16.02a has not solved the problem.

2. I am suspicious that there is some bug in how Maple 16 exports figures made with "plot" to a pdf file.

When I try various methods of compressing the pdf that I've seen on the web, such as with pdftk 1.44, or ghostscript 8.70 or 9.07,  or pdf2ps followed by ps2pdf ,

error messages are returned. For example using pdftk:

pdftk input.pdf output.pdf

gives

"Done. Input errors, so no output created"

## Solving Large Linear System of Algebraic Equations...

I have a large system of linear algebraic equations that I want to solve (2005 Unknowns, 2005 Equations). I was wondering that what are the proper commands to use in maple for solving the system as fast as possible. Take a look at the files in the download link if you want to see the system of linear algebraic equations.

http://pc.cd/h79

Please provide me any suggesitons that you may think will be helpful like using other sofwares that are good in doing this work such as MATLAB or something else.

## How to save values stored in the variables in a wo...

My problem is i am working with a very large randomly generated output, generated using maple's builtin in random generating functions. I have the output which i want to investigate but i want to be able to reproduce this result when i save and close the worksheet. Since the list of generators is very long copy pasting is not very nice and i donot know the seed of these generaters. I want to ask if i can store the values in variable in the worksheet so that when i open the worksheet i can get the same random generates stored in the variable.

## for loop for matrix...

Find a loop do define these matrices, even for large values of n. Record the Matrix Mn

all i,j=1,2,13,..,n for example

N := `<|>`(`<,>`(1, 2), `<,>`(2, 2))

P := `<|>`(`<,>`(1, 2, 3), `<,>`(2, 2, 3), `<,>`(3, 3, 3))

Q := `<|>`(`<,>`(1, 2, 3, 4), `<,>`(2, 2, 3, 4), `<,>`(3, 3, 3, 4), `<,>`(4, 4, 4, 4))

## (in expand/bigprod ) object too large...

Hello,

1-I have one calculation and the result is "Error, (in expand/bigprod) object too large"... What can I do with this error?

thamks alot.

## in expand/bigprod &Length of output exceeds limit ...

Hello,

1-I have one calculation and the result is "Length of output exceeds limit of 1000000"... What can I do with this error?

2-I have one calculation and the result is "Error, (in expand/bigprod) object too large"... What can I do with this error?

## large matrices and Rank mod p...

I'm trying to compute the rank of large, non-quadratic matrices modulo p=2,3,5 and 7.

For matrix-sizes of (approx.) 20000 x 20000 everything works fine with Rank(p,M) of LinearAlgebra[Modular].

But for (approx.) 40000 x 40000 even the parsing of the matrix is not finished after 5 days (for 20k x 20k this takes 1 or 2 hours) . The system I use has enough ram, so no swaping is involved.

First question: I expected the parsing to be O(n^2), why is this not the case?

## dsolve,numeric,stiff=true...

Hello all,

Is any anyone know how good is maple numeric stiff ode solver (stiff=true) ? What i mean is how many stiff ode's it can handle at a given time. I am having a hardtime solving a system of ode's (say 300 stiff ode's). Is there any other numeric stiff ode solver in maple that can handle large number of ode's?

I used islode advanced numeric solver for stiff ode's and it also has some limitations on the number of ode's and moreover it is slow.

## Determinants of huge 0-1 Matrices...

What would be the best way to compute the determinant of a very large (millions x millions) 0-1 matrix?