Signal Generators: Models and Emulations

## planet

```
ax,     planet     kmass1, kmass2, ksep, ix, iy, iz, ivx, ivy, ivz, idelta, ifriction

ay, az

```

### Description

planet simulates a planet orbiting in a binary star system. The outputs are the x, y and z coordinates of the orbiting planet. It is possible for the planet to achieve escape velocity by a close encounter with a star. This makes this system somewhat unstable.

### Initialization

ix, iy, iz – the initial x, y and z coordinates of the planet

ivx, ivy, ivz – the initial velocity vector components for the planet.

idelta – the step size used to approximate the differential equation.

ifriction – a value for friction, which can used to keep the system from blowing up

### Performance

kmass1 – the mass of the first star

kmass2 – the mass of the second star

ksep – determines the distance between the two stars

ax, ay, az – the output x, y, and z coodinates of the planet

### Example

```
instr 1

idur       =     p3

iamp       =     p4

km1        =     p5

km2        =     p6

ksep       =     p7

ix         =     p8

iy         =     p9

iz         =     p10

ivx        =     p11

ivy        =     p12

ivz        =     p13

ih         =     p14

ifric      =     p15

kamp       linseg 0, .002, iamp, idur-.004, iamp, .002, 0

ax, ay, az planet km1, km2, ksep, ix, iy, iz, ivx, ivy, ivz, ih, ifric

outs   ax*kamp, ay*kamp

endin

;   Sta  Dur  Amp   M1  M2  Sep  X   Y  Z  VX  VY  VZ   h   Frict

i1  0    1    5000  .5  .35 2.2  0  .1  0  .5  .6  -.1  .5  -0.1

i1  +    .    .     .5  0   0    0  .1  0  .5  .6  -.1  .5   0.1

i1  .    .    .     .4  .3  2    0  .1  0  .5  .6  -.1  .5   0.0

i1  .    .    .     .3  .3  2    0  .1  0  .5  .6  -.1  .5   0.1

i1  .    .    .     .25 .3  2    0  .1  0  .5  .6  -.1  .5   1.0

i1  .    .    .     .2  .5  2    0  .1  0  .5  .6  -.1  .1   1.0

```

### Author

Hans Mikelson
December, 1998
New in Csound version 3.50

Signal Generators: Models and Emulations