Hi all,

i was trying to make a package at my new maple 13. When bad and i ended up getting a error, when doing:

Driving me crazy:

lowest_gradient := proc(a) local i, b, c, gp, gn;

b := Array(1..5):
gp := Array(1..5):
for i from 1 to 5 do:
print(a);
b := a;
b[i] := a[i] + eps1;
gp[i] := b;
end do:
end proc:

d := lowest_gradient(initial_point);

 

If you try the loop for yourself, you will see that it is changing the value of the local variable a each time the loops runs, yet I have no idea why, since I have not put any code which should change the value of a.

 

I want to build a sequence with random step between numbers, the first number must be 0 and the last must be 10, for example:

No of numbers 6

[0,2,3,6,9,10]

seq function does not allow rand function, is there any other way?

Dear forum,

i have a MapleSim model that works flawlessly, no errors occur and the plot results are as expected. When i try to use a template however(Analysis, Equations), the following message pops up:

(in PiecewiseTools:-is) Wrong kind of Parameters in piecewise.

 

What could cause this ? Unfortunately, my model is not for the public yet, so i cannot show you the sheet.

 

Hints ?

I have a vector and after some manipulation, some of its values are rational and some are decimal with fixed 10 digits after decimal point which is default for maple 13, I want to show all of them in decimal numbers with no zeros, e.g.

[1.1000000000, 2/3, 2.3150000000,10.0000000000]

 

is there any way to do this?

Hi,

assume we have a cooling box that we open for a time period delta t. The box may be opened on top, so no cold air gets lost. What is the best way to model this in Maplesim ? So far, i have a heat capacity as box model for the cold air in it. I modeled a constant negative signal   during the time window delta t  and connected  a prescribed heat flow component to it.

 

Is this a reasonable model  in the easiest case ?

 

 

I have some troubles in solving a system of a complex equation using the function 'solve' of Matleb.The program finds no solution but a message of 'Warning: Warning, Warning: Explicit solution could not be found.

x=0:10000:500000;

solve('((2*y*(y/r^2-x)^0.5*besselj(1,(y/r^2-x)^0.5)*besselj(1,(y-x)^0.5))-((y-2*x)^2*besselj(0,(y/r^2-x)^0.5)*besselj(1,(y-x)^0.5))-(4*x*(y/r^2-x)^0.5*(y-x)^0.5*besselj(1,(y/r^2-x)^0.5)*besselj(0,(y-x)^0.5)))=0','y');

 

Hi all,

first of all I have to say that I'm newbie with Maple.

I tried soluting a 9 non linear equations system reading http://www.mapleprimes.com/forum/solving-a-set-of-linear-and-non-linear-equations but there's nothing to do: with solve or with a Groebner basis Maple looks for a solution for hours and then ends the memory available..

Is the system too much difficult? Can I calculate a solution? (My problem is a pole placement problem)

Thank you very much,

Riccardo

Hallo!

The Secure Hash Algorithm SHA-1 is based on the Federal Information Processing Standards Publication: http://csrc.nist.gov/publications/fips/fips180-3/fips180-3_final.pdf

Is there a procedure, function, maple worksheet, etc. availabe to calculate the SHA-1 with maple?

Thank you!

Johann

question1:When I Input a complex expression,the superscript is sometimes acceptable

I copy a good-form letter with superscript to the destination box,but the superscript is too high,a little far away the letter,and in the whole expression,they're not the same form!

How to solve it？

Hi,

Is there any way to generate a list of symbols from the equations in the worksheet automatically? If not is it possible to attach a note to each symbol and when the cursor is moved over it the description is displayed?

It is annyoing to generate a list of symbols manually.Any help is appreciated.

Regards,

Rishi

Hi,

have a look at this circuit, a simple Opamp-oscillator.  I can't get it to work with Maplesim, can someone show me how to simulate this ?

Btw it would be helpful if we could upload .msim files to mapleprimes. I renamed it to .doc, if you want the source.

Download 3795_oscillator1.doc
View file details

 

 

 

Hi, I have function like t^2+t+1 and I want to differentiate it with respect to time and set it an a new function, in order to calculate its derivation at some points. for example: a1_Func := (t)-> t^2 + t + 1; a2_func:=d/dt a1_Func(t); it works fine, but I can not call a2_func(t) at t=2 sec for example and it gives me an error saying "Error, (in a2_Func) invalid input: diff received 2, which is not valid for its 2nd argument". Please let me know how I can tell that the second function is also a function of time? Thank you,

Dear all, Is it possible to get a contourplot with NO contourlines? For example, I specified the "filledregions=true" in plot options. contourplot(-5*x/(x^2+y^2+1), x = -3 .. 3, y = -3 .. 3, grid = [15, 15], filledregions = true) But i do not want to show the contour lines inbetween... Thanks again for you help.

I am solving a dynamic problem however due to the complexity of the problem, the software runs out of memory. To avoid the memory los i am tring to write each time step solution into a text file however in order to do that i need to open a file using "fopen"

unfortunately this command enables writing to a file only if followed by "fclose" yet if the program stack before the file is closed the data is lost. on the other hand if i close the file after every time step the new file overrides the old one