Monthly Archives: April 2012

Unsupported hardware watermark box with AMD video driver.

I upgraded my Ubuntu system from 11.04 to 11.10 and Unsupported hardware watermark box was appeared on the right-corner of the screen, which is quite annoying and eyesore. For information, I have a 15 inch macbook pro 8,2. It was solved by:

http://wiki.cchtml.com/index.php/Ubuntu_Oneiric_Installation_Guide

and remove default AMD driver that delivered with 11.10 from “Additional driver option”. Then install the proper AMD driver. Commands that I used for reinstall AMD driver can be found from Installing Catalyst Manually section from the above link.

 


 

Nonlinear regression practice.

Nonlinear regression using MATLAB built in function. (LM algorithm)

http://en.wikipedia.org/wiki/Gauss%E2%80%93Newton_algorithm

Please download this data if you want to run a Matlab script

data

data = importdata('data.txt');
y=data.rate';
x=data.S';

myfunc = @(b,x)(b(2)*x./(b(1)+x));

b0=[0.1;0.1];
[ahat,r,J,cov,mse] =nlinfit(x,y,myfunc,b0);

xrange = min(x):.01:max(x);
hold on
scatter(x,y)
plot(xrange,myfunc(ahat,xrange),'r')
hold off
ahat
ahat = 0.5563, 0.3618