5 years, 67 days

## Get rhs of equation in matrix...

Maple

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]]);`

## Solve ode with time and input vector fro...

Maple

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

## How to find parameters that satisfy the ...

Maple 2015

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

## Piecewise function - How plot function ...

Maple 2015

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

## Problem with subs function in Maple...

Maple 2015

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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