Xu Cui
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564 Stories by Xu Cui
This is an example of brain activation plotted on surface. In many circumstances surface view is much more straightforward than a slice view. Here is how I created such a plot using MatLab and SPM. Environment and Tools: Windows XP MatLab (v7.6) SPM
We use TCP/UDP/IP Toolbox 2.0.5 to read and write data from/to a TCPIP port. It’s fast and reliable. The version we use is 2.0.5. Below is a matlab sample script showing how to connect to another computer (called ETG-4000) with TCPIP : %Connect
Noise removal methods in NIRS can be divided into 4 categories: reducing noise based on its temporal characteristics: The instrument noise is usually in the high frequency band and thus can be removed by band pass filtering. Band pass filtering can a
As I have quite some emails (>13000) in gmail, searching more efficiently becomes a necessity. Fortunately gmail offers some advanced search syntax. http://mail.google.com/support/bin/answer.py?hl=en&answer=7190 Search emails with attachment f
I just became a new father. My daughter Iris was born 4 days ago. Currently sleep deprived …
Assume you have a vector (x,y,z) and you want to rotate it to, say x-axis, you can multiply the rotation matrix to the vector. First, make the vector a column vector and append 1 to the end. It becomes a 4×1 matrix: v = x y z 1 Then, convert the
Several years ago in San Diego I was in a friend’s car when he hit the car in front. The accident was mild and nobody was injured. After the two cars pulled over, I was wondering what the other driver would say. He said, “I am sorry to me
I saw at least two web pages saying that the reference slice can be chosen during slice timing correction. For example, http://www.fil.ion.ucl.ac.uk/spm/doc/manual/spatial.htm. I disagree. Let’s take the first volume as example. Assume TR=2 and
y: dependent variable X: independent variable r: residual $$y=X\beta+r$$ $$\beta=inv(X’*X)*X’*y$$ $$\sigma^2=r’*r/df$$ $$df=N-rank(X)$$ $$\sigma_\beta^2=\sigma^2inv(X’X)$$ $$T_\beta=\beta/\sigma_\beta$$ $$contrast variance = c