Rariusz

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5 years, 67 days

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These are questions asked by Rariusz

I have matrix:

m1 := Matrix([[x[0,0]=1,x[0,1]=1,x[0,2]=0,x[0,3]=0,x[0,4]=0,x[0,5]=0],[x[1,0]=0,x[1,1]=0,x[1,2]=1,x[1,3]=1,x[1,4]=0,x[1,5]=0],[x[2,0]=0,x[2,1]=0,x[2,2]=0,x[2,3]=0,x[2,4]=1,x[2,5]=1]]);

How to get values on the rhs of x without using for loops and create a matrix using these values?.

Results should be:

m2 := Matrix([[1,1,0,0,0],[0,0,1,1,0,0],[0,0,0,0,1,1]]);

 

I solve ode for simply DC motor system:

J:= 0.01;b:=0.1;K:= 0.01;R:=1;L:=1;
eq1:=J*diff(theta(t),t,t)+b*diff(theta(t),t)=K*i(t):
eq2:=L*diff(i(t),t)+R*i(t)=V-K*diff(theta(t),t):

ICs:= theta(0)=0, D(theta)(0) = 0, D(theta)(0) = 0, i(0) = 0:
sol:=dsolve({eq1,eq2,ICs},numeric,parameters=[V],output=listprocedure):
sol(parameters=[10]):
ode_x1:=sol[2];
ode_x1:=rhs(ode_x1);
ode_x2:=sol[3];
ode_x2:=rhs(ode_x2);

p1:=plot([ode_x1(t),ode_x2(t)],t=0..50,gridlines=true):
plots[display](array([p1]));

I have time wektor and input wektor V in csv file. How to change this code to simulate 

ode solution ode_x1 and ode_x2 with data from file? Now I set V as 

sol(parameters=[10])

and t in 

plot([ode_x1(t),ode_x2(t)],t=0..50,gridlines=true)

Best

Hello,

I have the follownig set of inequality:

{0 < p[1, 2], p[1, 1] < 2*p[2, 2]+(3/2)*p[1, 2], p[1, 2]^2/p[2, 2] < p[1, 1], (2/3)*p[1, 2] < p[2, 2]}

Now I need to find value of p11,p12,p22 that satisfy the above inequality. Is there any easy way to find

parameters p11, p12, p22 in maple?

Best

Hi

I have the following piecewise function in Maple:

sigmaP:=piecewise(u < -1,-1,u >1,1,u);

Now we can plot this function:

plot(sigmaP,u=-5..5,size=[1200,300],gridlines,discont=[showremovable]);

Next, I define a new piecewise  function as

sigmaF:=u->piecewise(u < -1,-1,u >1,1,u);

and I use this function in 

Fun:=proc(x1,x2,u1,u2)
	2*x1*(1+x2)*sigmaF(u1)+(1+x2^2)*sigmaF(u2);
end proc:

Now I need to find a minimum of this function so I use the following code 

GlobalOptimization:-GlobalSolve(Fun,x1,x2,u1,u2);

where 

x1:=-5..5;
x2:=-10..100;
u1:=-1..1;
u2:=-1..1;

And I have the problem with plot function Fun. How to plot function Fun???

Best

 

Hello,

For example, let's say we have the following function

 

Now if we want to calculate the value of a function we have to

subs([x1=10,x2=20],eval(hf));

My question is the following: How to substitute values for x1 and x2 using values from vector? something like that

x:=[10,20];

subs([x],eval(hf));

 

Best,

Rariusz

 

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