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gkokovidis

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20 years, 291 days
Draeger Medical Systems, Inc.
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Regards,
Georgios Kokovidis
Dräger Medical

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These are answers submitted by gkokovidis

How do I plot this?...

gkokovidis 2370
February 27 2011
2 0

You need to define your constants, otherwise you will get the error message unable to evaluate the function to numeric values in the region.

Your factored equation is missing a multiplication sign.  Using your original equation, your can use plot3d as below.

 

> 

restart:
> 

A:=1;m:=1;alpha:=1;beta:=1;

 

 

 

(1)
> 

y(theta,t):=1/4*Pi + A*sin(m*theta) + A*sin(m*theta)* (exp(-1/4 *alpha^2*beta^2)-2)/(4*Pi)*t;

(2)
> 

plot3d(y(theta,t),theta=-Pi..Pi, t=0..10);

 
> 

 

To see the plot with the parameter "A" varying, animate it as follows:

>with(plots):

>animate(plot3d,[y(theta,t),theta=-Pi..Pi, t=0..10],A=1..20,axes=boxed);

 

 

Regards,

Georgios Kokovidis

Dräger Medical

Break it up...

gkokovidis 2370
February 24 2011
2 0

As a workaround, you can break it up into 3 individual LineCharts, and use display to combine them.

 

> 

restart:with(plots):
> 

with(Statistics):
> 

> 

> 

> 

a:=LineChart(A, gridlines = true,linestyle=dash,thickness=3):
> 

b:=LineChart(B, gridlines = true,linestyle=solid,thickness=3):
> 

c:=LineChart(C, gridlines = true,linestyle=dot,thickness=3):
> 

display(a,b,c);

 
> 

 

 

Download LineChart.mw

 

Regards,

Georgios Kokovidis

Dräger Medical

One way...

gkokovidis 2370
February 24 2011
0 0

Look @ the help page for the ?op command.   Is the Matrix below adequate?

> 

restart:
> 

A:=sqrt(I);

(1)
> 

RealA:=op(1,A);

(2)
> 

ImagA:=op(2,A);

(3)
> 

Bs:=Matrix([[RealA, ImagA], [ImagA, RealA]]);

(4)
> 

 

 

Download MatrixRealImag.mw

 

 

Regards,

Georgios Kokovidis

Dräger Medical

You are correct...

gkokovidis 2370
February 23 2011
0 1

The Im command only returns the constant part in front of the"I", so what you see is corect.  In your specific example, the constant in front of the "I" is 1/2*2^(1/2).

As another example, try Im(I).  Maple will return 1 as the answer.  Again, the "I" does not get displayed.

 

Regards,

Georgios Kokovidis

Dräger Medical

Cube root as function...

gkokovidis 2370
February 22 2011
1 0

See an explanation of why you are getting a non-real answer here.

To use 'surd' with functional notation, you can do it like this.

> 

restart:
> 

f:=x->surd(x,3);

    (1)
> 

f(-8);

                          (2)
> 

 

Download CubeRoot.mw

Regards,

Georgios Kokovidis

Dräger Medical

Application Center...

gkokovidis 2370
February 19 2011
2 0

This link has a worksheet that is similar to what you are looking for.

 

Regards,

Georgios Kokovidis

Dräger Medical

DEplot error...

gkokovidis 2370
February 05 2011
0 1

Can you post your worksheet?  What is else do you have ahead of this?  Cutting and pasting the code where you show an error gives me a plot.

 

> 

restart:with(DEtools):
> 

deqn := diff(x(t), (t$2)) = -2*(diff(x(t), t))-25*x(t);
> 

DEplot(deqn, x(t), t = 0 .. 10, [[x(0) = 1, (D(x))(0) = 0]], stepsize = .1, linecolor = blue, thickness = 1);
>   

 

 
   

 

Download deplotprob.mw

 

Regards,

Georgios Kokovidis

Dräger Medical

?plotsetup...

gkokovidis 2370
February 02 2011
1 7

The code below will export a jpeg to currentdir, which for me is C:\EngineeringApps\Maple14

You can set this to whatever makes sense for you.  ?currentdir and ?plotsetup for more help on this.  The last line resets the plot setup to the original ouput device (screen).

currentdir();
                  "C:\EngineeringApps\Maple14"

plotsetup(jpeg,plotoutput="plotexport.jpg");
plot(2*x^2+3*x-4,x);
plotsetup(default);

Regards,

Georgios Kokovidis

Dräger Medical

Example...

gkokovidis 2370
February 02 2011
0 0

Here is an example that you can modify using your functions.  See the help page for ?piecewise for more details.

p := piecewise(x < 0, sin(x), 0 < x and x < 2*Pi, cos(x),x>2*Pi, 2);

plot(p);

 

Regards,

Georgios Kokovidis

Dräger Medical

Help page for dsolve command...

gkokovidis 2370
January 31 2011
0 0

See the help page for the dsolve command with initial conditions.  There are examples there that you can modify for your own equation.

?dsolve/ics will get you there.

 

Regards,

Georgios Kokovidis

Dräger Medical

?plottools[reflect]...

gkokovidis 2370
January 25 2011
0 1

How about this?  ?reflect for the help page.

> 

restart:with(plottools):
> 

plot(x^2,x=-1..1,y=-1..1);

 
> 

p:=plot(x^2,x=-1..1,y=-1..1):
> 

reflect(p,[[-1,0],[1,0]]);

 
> 

 

 

Download reflect.mw

 

Regards,

Georgios Kokovidis

Dräger Medical

Is it possible to re-orient the axis of ...

gkokovidis 2370
January 25 2011
1 1

See if the link below answers your question. 

http://www.mapleprimes.com/questions/42659-Reverse-Yaxis-Direction

 

Regards,

Georgios Kokovidis

Dräger Medical

Can this integral be calculated?...

gkokovidis 2370
January 22 2011
0 0

Not with the current version (14).  I also tried it with version 9.51 and it returned unevaluated.  No assumptions were made about a and b.

 

> 

restart:
> 

int((1/sqrt(2*Pi))*(1/(1+exp(x)))*exp(-(1/2)*((x-a)/b)^2),x=-infinity..infinity);

(1)
> 

 

 



Download uneval_int.mw

 

 

Regards,

Georgios Kokovidis

Dräger Medical

plotting Splines...

gkokovidis 2370
January 20 2011
0 0

I do not see any attachments.  It the example below similar to what you are doing?

 

> 

restart:
> 

with(CurveFitting):
> 

f:=x->Spline([[0, 0], [1, 1], [2, 4], [3, 3]], x);

(1)
> 

g:=x->1/f(x);

(2)
> 

plot(f(x),x=0..5,y=0..8,thickness=2);

 
> 

plot(g(x),x=0..5,y=0..8,thickness=2);

 
> 

 

 

Download splineplot.mw

 

 

Regards,

Georgios Kokovidis

Dräger Medical

?StringTools[CharacterFrequencies]...

gkokovidis 2370
January 20 2011
2 0

Look at the help page for ?StringTools[CharacterFrequencies] to get you started.  Look at some of the other help pages, and do a search on the web.  Please do not ask others to do your homework for you.  Show what you have done, and what you are having trouble with.  Then you might get some help.  Otherwise, ...

 

Regards,

Georgios Kokovidis

Dräger Medical

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