added modelica spring example, powershell clearfiles script

*.ini

*.mat

*.o

*.libs

*.log

*.makefile

*.c

*.h

*.xml

*.exe

*_info.json

.ipynb_checkpoints/

%% Cell type:markdown id: tags:

# Modelica x Jupyter

These cells contain modelica code that can be run via Jupyter.

To install:

* Install OpenModelica

* Install Anaconda

* Create environment in `env.yml`

```

    conda env create -f env.yml

```

%% Cell type:code id: tags:

``` OpenModelica

class Pendulum "Planar Pendulum"

class Pendulum "Pendulum"

   constant Real PI=3.141592653589793;

   parameter Real m=1, g=9.81, L=0.5;

   Real F;

   Real F;  // External force tengential to motion

   output Real x(start=0.5),y(start=0);

   output Real vx,vy;

   output Real vx,vy;      // x and y velocities

equation

   m*der(vx)=-(x/L)*F;

   m*der(vy)=-(y/L)*F-m*g;

   der(x)=vx;

   der(y)=vy;

   x^2+y^2=L^2;

   m*der(vx)=-(x/L)*F;     // Force equation in x direction

   m*der(vy)=-(y/L)*F-m*g; // Force equation in y direction

   der(x)=vx;              // Relating x position to x velocity

   der(y)=vy;              // Relating y position to y velocity

   x^2+y^2=L^2;            // Constraining x, y to string length

end Pendulum;

```

%% Cell type:code id: tags:

``` OpenModelica

simulate(Pendulum)

```

%% Cell type:code id: tags:

``` OpenModelica

plot(der(x),der(y),m)

```

%% Cell type:code id: tags:

``` OpenModelica

class Spring "Damped Spring"

    // mass, gravity, spring constant, air, contact resistance

    parameter Real m=0.5, g=9.81, k=3, r_a=0.1, r_c=0.0;

    output Real x(start=0.0);  // x position

    output Real vx(start=0.2); // x velocity

equation

    m*der(vx)= -k*x - r_a*vx - r_c*m*g; // force equation

    der(x)=vx;  // relating position to velocity

end Spring;

```

%% Cell type:code id: tags:

``` OpenModelica

simulate(Spring)

```

%% Cell type:code id: tags:

``` OpenModelica

plot(der(x), x)

```

```

    conda env create -f env.yml

```

On Windows, set the environment variable `OPENMODELICAHOME` to point to the installation directory for OpenModelica.

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rm *.o

rm *.libs

rm *.log

rm *.makefile

rm *.c

rm *.h

rm *.xml

rm *.exe

rm *_info.json

rm dygraph-combined.js

 No newline at end of file