When I use Openmaple with C#, if the command line involves "MapleEngine.StopMaple" or "restart", or the command line including "MapleEngine.EvalMapleStatement" is executed twice (sometimes more), it always cause a crash. Can anybody help me out with this problem? Thank you in advance!

The following is the crash report:

unhandled System.AccessViolationException
  Message=Attempted to read or write protected memory. This is often an indication that other memory is corrupt.

i'm using maple 15 and trying to solve the following PDE without success, can you help please.

(ab+(a*sin(x1))^2-(c*cos(x1))^2)*d/dx1(V(x1,x2))=-dsin(x1)/exp(x1).

where a,b,c and d are constants. and i need it to be solved as a PDE please.

thank you,

Mutaz

hello,everyone,
I have a problem to make a figure, commands are below:

restart;
1+(2*(S1*e2/(S2*e1)+S2*e1/(S1*e2)))*tanh(S2*k*d);
S1 = sqrt(beta^2-e1), S2 = sqrt(beta^2-e2);
e1 = 4, e2 = -19-.53*I;
subs(`%%`, %, k = 2*Pi/(0.633e-6), `%%%`);

I want to plot the relation between d and beta(real part named betar and imaginary part betai),but meet some trouble.
I got some points from the article is when d=400e-10, betar in the range (2.1,2.2...

Is there another way to plot 3d intensity levels in an image?  Using matrixplot takes a long time. 

restart;gc():
with(ImageTools):
with(plots):

a:=Read("c:/lighthouse1.jpg"):
b:=convert(ToGrayscale(a),Array):
c:=convert(b,Matrix):

matrixplot(c,style=point,shading=zhue)

martixplot(c,style=point,shading=zhue,orientation=[0,0])

The operation: 2^29.403243784 gives me 7.0999999820*10^8.

However, using WolframAlpha, the answer is 7.10000000139658667836958142950829925944726171959 × 10^8.

These are 2 different answers. Can someone offer an explanation as to why this occurs and how I can avoid this problem?

Thanks in Advance!

Eddy Liu

Good morning everbody,

I am currently trying to get string and numerical datas from a txt.file but I don't get how to do this.
I have done this in matlab but I would like to make it in maple.
I have read other post about the subject and try tried this command:

 fd := fopen(dataFile,READ,TEXT):
    theData:=readdata(fd,string, 3): # 3 columns
  fclose(fd):

  A:=convert(theData,Array);

but it didn't help me. 

Hi , 

 u(t-n*Pi)=0 if (t-n*Pi)<0

 u(t-n*Pi)=1 if (t-n*Pi)>=0

need to plot y(t) against t where t=0..30:

y(t)=sum(sin(t-n*Pi)u(t-n*Pi),n..infinity)

I appreciate 

How should I save my result-expression so as to be able to use it directly in other file without having to generate it again.

please help
regards,

Hi,

My work requires me to use derivative a lot. Especially, the partial one. Given F(x,x_dot). Maple has this partial expression, however I'd like to partial differentiate F with regard to x_dot (the derivative of x over time).

Is this possible? If possible, please tell me how.

Thank you.

Abe

i had a 15 set of nonlinear PDEs,i convert them to nonlinear set of ODEs, i try to solve them using the command dsolve(numeric) , but when solving i face this erroe :

Error, (in DEtools/convertsys) numeric exception: division by zero

what should i do?the problem is in my equations ? or what?

with regards,thnx. 

Hello, 

I'm importing some other modelica models from other softwares (like open-modelica and dymola) inside maplesim. I can work in a full compatible code, except for the lookup table. Some of the models I'm importing as a library uses the standard lookup tables (not the ones given by maplesim) - I tried to run those standard lookup tables (from the modelica library) in maplesim, but it does not work.

Is there a way to solve...

A wonderful plot I have found created by Matthius Kawski in Maple 8.  But newer versions creates an Error, (in f) unsupported type `complex(float)` in evalhf in the DEplot.  Can someone fix the error?  Worksheet is attached.

lyap-not-proper.mws

I have this csv file on my website (the file is hosted on dropbox.com) that I want to load into Maple:
Hence I type:

URL := "https://dl.dropboxusercontent.com/s/7fqalrdtn0c3r8u/Stockholm%20Stock%20Exchange%28Percentage%20Change%29.csv?token_hash=AAGxpzva90O6oNlLAie3T1h0UNP06I5EPg2qrROHMglRMw&dl=1":
HTTP:-Get(URL, 'timeout' = 100)

Then I get:

Error, (in HTTP:-Get) timed out waiting for initial response from server

If you past the url into...

Here is a relation: t[n+1]:=((a*n^2+a*n+b)*t[n]+c*(n^2)*t[n-1])/(n+1)^2

t[-1]:=0 and t[0]:=1

a,b,c are integers and a,b,c are from 1 to 20 and n is from 0 to 20

the series t[n+1] is integer

I want to know how to list (a,b,c) that satisfies the above. Please help!

I was using the Finance package and used the command ImpliedVolatilitySurface(...). But it is showing the following error 
"Error, (in Finance:-ImpliedVolatilitySurface) external linking: error loading external library finance.dll: The specified module could not be found."Please help..