Can you find any pattern in the two signals, green and blue? The blue signal is the brain wave (measured by NIRS) of a person when he is pressing some buttons (the timing of button pressing is shown i
Wavelet transform coherence (WTC) is a method for analyzing the coherence and phase lag between two time series as a function of both time and frequency (Chang and Glover 2010). Here I played with it
SVM is mostly commonly used for binary classifications. But one branch of SVM, SVM regression or SVR, is able to fit a continuous function to data. This is particularly useful when the predicted varia
Update 2021/2/27: If you find griddata3 not working, try to change griddata3 to griddata. I was asked where to get nirs2img script. Here it is. The download link is at the bottom of this article. nirs2img is to create an image file from the input data. Then theimage file can be viewed by a
Ric Elias is the CEO of Red Ventures, a marketing services company that grew out of Elias’ long experience in business. He had a front-row seat on Flight 1549, the plane that crash-landed in the Hudson River in New York in January 2009. What di
Laplace introduced the sunrise problem in 18th century. With prior knowledge that the sun has risen N days in the past consecutively (not knowing the gravity rules etc), what is your confidence that the sun will rise tomorrow? Let p be the probabilit
Let’s say you have two correlated variables, x and y. You may have more then one data points with x=10 and y=5. But if you do a scatter plot all these data points of the same value will become a single dot. You may want to use circles with size
In case you need to visualize your time series in both time and frequency domain (or just frequency domain), you can use the wt (wavelet transform) function in the Cross Wavelet and Wavelet Coherence toolbox by Grinsted et al. I often find the color
Sometimes you wish to know the spectrum of a time series. plotFFT is a handy function for this purpose. You instantly know the power of the signal at each frequency. Here is an example on how to use this function: figure; plotFFT(randn(1,1000)); Sour
Often you need to view the spatial pattern of activation as in the example below. plotTopoMap allows you to do that. It probably only works for Hitachi devices where the spatial relationship between channels are known. In the above example, the activ
You often need to plot the time series of NIRS signal from all channels with event indicators (See the example below). plotTraces can do that easily. In the above example, time series of all 24 channels are plotted. The number on the y-axis indicates
Quite often you need to call external or system commands inside MatLab. If those external commands are not in path, you need to add them. Here is how: setenv('PATH', );
I use SPM’s dicom import function to convert DICOM files to Analyze files. But it’s quite inconvenient if I have 20 subjects. Below is a script to do this conversion automatically. You can call this function inside a loop. function dicom2
