Hi - I'm trying to solve a PDE using pdsolve() for the Graetz problem (heat transfer in a pipe). I can solve the PDE and get a general solution, but when I try to solve the equation with the boundary conditions, Maple thinks that the boundary conditions are new functions with the same name. Here is how I am doing it now: > heat := (1-z^2)*(diff(T(y, z), y)) = (diff(z*(diff(T(y, z), z)), z))/z; > cond := T(0, z) = 0, T(y, 1) = 1, diff(T(y, 0), z) = 0; > PDE := [heat, cond]; > sol := pdsolve(PDE, T(y, z)); This throws the error:

I need to find the square root of a large number, x (about 70 digits long).  If I use x^0.5, the answer is displayed in scientific notation and  is rounded.  How can I find this number exactly?

I have 2 functions, f(x) and g(x) both continous on [a,b] (a known interval). For which value of C ε [a,b] the area under f(x) and g(x) is minimal?

I know f(x) and g(x).

I have 2 functions, f(x) and g(x) both continous on [a,b] (a known interval). For which value of C ε [a,b] the area under f(x) and g(x) is minimal?

I know f(x) and g(x).

In implicitplot, to insure the accuracy  of a curve, I usually increase the number of points (numpoints=*** ) or increase the number of grids ( grid=[***,***] ). Both can improve the quality of the curve. And sometimes one works better than the other. But I don't quite understand the relationship between the two options , and which is more effective and more economical. Thanks.

I want to plot  the astroid by the following code, but only the part in the first quadrant appears. I don't know that is wrong and how to solve the problem. Thanks.

with(plots):
a:=1:
implicitplot(x^(2/3)+y^(2/3)=a^(2/3),x=-a..a,y=-a..a);

Hello

I am running NLPSolve within a loop over some values of parameters. For one of the parameter values, the NLPSolve gives me

Error, (in Optimization:-NLPSolve) no improved point could be found
 

and exits the loop. How do I change this behaviour? I would like the loop to continue for other parameters.

I have tried interface(errorbreak=0) interface(errorcursor=false) but this didn't work.

Can anyone help please.

Thank you, Best Regards

Jan Zapal

 

 

In Maple 11 I need to write define_external procedure with 23 arguments.

For example:
   test1 := define_external('myproc',
                                               N1::(integer[4]),

A few weeks ago I mentioned the ncrunch comparison of "mathematical programs for data analysis" in a comment in another thread.  There is now a new, 5th release of that review. The systems reviewed are:

• GAUSS
• Maple
• Mathematica
• Matlab
• O-Matrix
• Ox
• SciLab

The review is skewed towards statistical computation and data manipulation, but it includes several interesting comparisons of the major computer algebra systems (CAS).

There is a comparative performance section, and the worksheets used for that benchmarking are available for download. Here is the Maple worksheet, which was used with Maple 11.

Hi

 

how can i do this in maple

 

if(a>b>c) then 4

 

or maybe if(a>b) and if(b>c) then 4

All:

This should be simple but I am clearly missing some of the nuances - can you please help me see what I am doing wrong?  I would like to solve 2 eqns in 2 unknowns:

eq15 := Kzeff15 = (Kvr*Kz15)/(Kvr+Kz15);

eq33 := Kzeff33 = (Kvr*Kz33)/(Kvr+Kz33);

Kz33 := (3.3/1.5)*Kz15;

Kzeff15 := 150612;

Kzeff33 := 253629;

soln_z15 := fsolve ({eq15,eq33},{Kvr,Kz15});

 

 

Greetings all

I would like to show the x y values next to the point on the plot does maple have a command to do this?

data := [[0, 0], [.5, -1], [1, 0], [2, 2], [3, 0], [5, -4], [7, 0], [11, 8], [15, 0], [18.5, -7], [22, 0], [24.5, 5], [27, 0]];
 with(CurveFitting);
cubfit := BSplineCurve(data, x, order = 3);
plots[display](plot(data, style = point, color = black, symbol = BOX),
plot(cubfit, x = 0 .. 27, thickness = 2))

 

tia sal

What is the best way to print a maple file?  It seems that a lot of white space is added when making an html file.  Also it scrambles in a ton of strange symbols when its in a pdf, Im just trying to figure out how to print a 3 or 4 page maple worksheet without it printing on 20 pages!

 

Thanks!

How can I plot sin(y)>0, x>0 ?

I've tried using inequal:
with(plots):
inequal({sin(y)>0,x>0}, x=-2*pi..2pi, y=-2*pi..2*pi);

but I get the message 'unable to compute coeff' .

Thanks in advance.

I'm interested in finding a command that could stretch slope fields for me. Or perhaps I need to make a procedure of my own?

If that is the case, I would like to know how to draw a segment of a graph by varying the slope.

I think it is possible for me to use

with(geometry);

segment([y=y'*x+C, [x,y]],a,b);

But I don't have any idea how to make a program out of it yet.

 

Thanks in advance :)