[sc-users] Converting Physical Model Code from Matlab

Hello,

I'm trying to convert some code for a physically based model in Matlab to an SC synth def. The model below represents an oscillating air bubble in water. In Matlab it would be possible to synthesise an array of pressure values which would be automatically scaled. If I read data into a buffer in SC, is it possible to do the same??

I'm also getting an error in the last line of the loop in the code below, maybe a syntax thing to do with the beta value?? Im not so sure about mathematical syntax in SC, I don't know how to multiply arrays with each other ("dot" product), hence the need for the loop, I can't work out why I'm getting an error though...

Thanks,

Patrick

Code:

(

SynthDef(\bubble2,{

var sr,c,bit,x,f2,r,r2,pres,pres2,rho,gamma,eps,f,gth,deltaTh,deltaRad,deltaTot,beta,xi;

sr = 44100;

//output - 1 sec

x=FloatArray.new(sr);

//frequency array - 1 sec

f2=FloatArray.new(sr);

//Speed of sound

c=1497;

bit =32;

r=0.015;

r2=FloatArray.new(sr);

//Minneart

pres=100000;

pres2=FloatArray.new(sr);

rho=1000;

gamma=1.4;

eps=0.05;

f=(1/(2*pi))*sqrt(3*gamma*pres/(rho*(r**2)));

//Vertical velocity

xi=0.1;

//Damping constant

gth=1.6*10**6;

//Thermal Damping

deltaTh=sqrt(9*(gamma-1)**2/(4*gth)*f);

//Radial Damping

deltaRad=sqrt(f*r/c);

//Total Damping

deltaTot=abs(deltaTh)+deltaRad;

//Decay rate due to damping

beta=pi*f*deltaTot;

for(1,sr,{arg i;

//Array of subsequent frequencies

f2(i)=f*(1+xi*beta*(i)/sr);

//Resulting pressure wave emitted from bubble

x(i)=eps*r*sin(2*pi*f2(i))*(i/sr)*exp(-beta*i/sr);

});

}).load(s);

)