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?

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?

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, 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

 

I had a look at the Maple application "An Interactive Stock Quote Importer"  www.maplesoft.com/applications/view.aspx

which is quite nice :-)  I did not really understand how the author (Samir Khan Maplesoft ) managed to download

yahoo finance data directly inside Maple so I sent him an email asking. He sent me some quite nice code (which I

simply put in a procedure ) that downloads data for any specified ticker symbol from yahoo finance:

 

Hallo!

I have converted a decimal number to hexadecimal, the result in hex is: 18DBD3547552C73BE4DE87731C500.

I think the from Maple converted (decimal to hexadecimal) number ist Big-Endian.

Is there a command in Maple to make this number 16 Byte long (00018DBD3547552C73BE4DE87731C500) and to convert this hex-number to Little-Endian (00C53177E84DBE732C554735BD8D0100)?

Thank's for help.

Johann

Is it possible to see the algorithm used by msolve(eqs,2) ? The help page just says

"The procedure msolve has special code for efficiently handling large systems of equations mod 2. "

but I would like to know exactly what it is doing.

I tried print(msolve); and then print(ModularSolver:-Solve); but didn't get anywhere.

Raphael
                 
 

How can i plot x-exp(-y^2)=o and sin(5x)/x + 2 − (y − 1)2 = 0.on the same graph maple just repeats whatever input i put in