MaplePrimes Questions

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displayprecision and typesetting...

According to the help page:
interface(displayprecision=n)
sets the number of decimal places to be displayed to n.
But this is true only if interface(typesetting=extended).
For interface(typesetting=standard),  n represents the number of decimal places after the decimal point.
Is there any reason for this decision?

restart;
x:=123.456789012345:
interface(displayprecision=4):
interface(typesetting=standard): x;

123.4568
interface(typesetting=extended): x;
123.5

Using subscripts to solve equations?...

I'm trying to calculate forces between particles. I defined all my variables and the equation for force, but when I plug it all in, it gives me 0 when I know for a fact it's not 0. I should be getting something like f12=-0.4, f13=-0.24, and f23=-0.5.

failforce.mw

Basically I defined variables like x1,y1, m1 , etc. and made my force equation fij with all variables having appropriate i and j subscripts.

I want to write this function with  "for"...

hello. i want to write this function with  "for"loop. but i don't know
1.mw

3D animation of rotation?...

Hello!
Used PolyhedralSets for plotting.
At the moment there are a number of questions in the construction of graphs:
How to adjust the rotation of this figure around the z axis?
How to make, what color of a figure received in a cut would be much darker or Darker color?

with(PolyhedralSets);
P1 := PolyhedralSet({-x-20 <= 0, -x-20 <= 20-y, -x-20 <= -(1/2)*y, -x-20 <= -z, -x-20 <= -(x+y)*(1/2), -x-20 <= -(y+z)*(1/2)});
Plot(P1, axe
s = normal, view = [-40 .. 40, -40 .. 40, -40 .. 40], orientation = [30, -30, -60], color = blue, thickness = 2);
Plot(P1, axes = normal, view = [-40 .. 40, -40 .. 40, -40 .. -40], orientation = [0, 0, 0], color = blue, thickness = 2)

I'm trying to obtain integral of Planck radiation law in Maple:

with this command:

f := (2*h*(c)^(2))/((x)^(5))*(1)/(exp((h*c)/(x*k*T))-1);
int(f,x=0..infinity);

but I get some terrible limit that cannot be solved instead of the correct result:

How to obtain correct integral?

planck.mw

DC Motor example - How do i get output in plot...

I followed the basic example RLS circuit first. It worked out well for R = 24 ohms, L = 160 mHand C = 200 microF. Signal is step input h = 1 and  t0 =  0.1 s. Simulation td = 0.5 s

When I extended it for DC motor, the output for torque (tou) and speed (w) not plotted for h = 1  t0 =  1s and simulation td = 5 s for the same parameters as above the output required (shown in manual) is not coming. Is it because default values shown were different? Then how do i change? I am enclosing the file for view and help.

DCmotort_model1.msim

Thanks.

Ramakrishnan V

How to lebel a big math expression on vertical axi...

How to lebel in inline math mode. I tried labels = ['theta', Typesetting:-Typeset(cos(1/theta)/sqrt(1-theta^2))] which gives a big expression on Y axis spreaded in two lines. But i want to lebelin one line as in latex $\cos(1/\theta)/sqrt(1-\theta^2))$ . Is there a way to do it ?

boundary conditions...

the program shows that the error please verify it sirprogram11.mw

Constraints on Revolute Joints...

Hello,

I have an industrial robot model and I need to define constraints for the revolute joints. For example, R2 joint is only allowed to move between -165 to 165 degrees. Could you please tell me how I can impose these constraints?

Thank you.

Önder

problem with PDE ...

what's the problem with PDE below? tnx for help

 > restart:
 > PDE:=diff(u(x,t),t)=k*diff(u(x,t),x\$2)-h*u(x,t);
 (1)
 > IBC := {u(-Pi,t)=u(Pi,t), (D[1](u))(-Pi, t) = (D[1](u))(Pi, t),u(x,0)=sin(x)};
 (2)
 > pdsolve(PDE,IBC);
 >

Solving and optimizing problem...

Hi

I have two equations as follows:

The goal is finding the parameter 'phi'. This parameter is a positive real numeric constant.

I uploaded two files that they are included two methods to solve the problem.

1.mw

2.mw

Is method in the first file mathematically logical? If it is a correct method, why the command fsolve dosent work?

In file 2, we have 2 equations with further indeterminantes. The constant 'phi' must be minimum possible amount. How we can use the commands like the Minimize in Optimization? Please hint me.

Thank you very much

Insering Legend inside the figure plot ...

I want to set the position of the legend inside the figure window for example say top right in the figure window. Maple chose the legend to be at right, left, top, bottom outside the figure window. How can I place the legend of my own wish?

thanks,

Maple cause error but doesn't show the reason...

I am coding a big module to solving my project : analyze function in math, but when I compile my module maple return "Error," but it doesn't tell me what error happened.

I check the maple help and it said:" If no msgString is given, error raises the most recently occurring exception" but I have no exception before.

This is the pic of that error.

Can I plot3d with an condition?...

I would like to look at a 3d plot including an condition about the tree variables of the plot

For this simple case, I only want to see the plot with the condition that
{40 < y, x < y-40, z < y-40} or {x = 0, y = 40, z <= 0}, {y = x+40, 0 < x, z < x}, {y = x+40, z = x, 0 < x}

. Is that possible?

In 2d there is no problem. And in 3d I do not know how.

how do i get rid out of error for ploting hardenin...

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print(output redirected...); # input placeholder