( Under Construction )
1. An Interactive Digital Filter Design Tool in MATLAB

This is an interactive digital filter design package I developed using MATLAB for GEO384R in the fall 1994 as a term project. Two windows will be required to perform the interactive filter designing. One window is used to operate the zeros or poles on the Z-plane, while the other window is used to display the response functions (power response and phase response) comparing to the desired response functions simultaneously. This software provides functions to ADD, DROP, and MOVE any one or one pair zeros or poles with simply button clicking

MATLAB not only contains mathematical functions, high level signal and image processing tools, but also provides powerful language functions which enable users to implement high level applications. MATLAB's script language characteristics make it very easy to learn, to apply, and even to access and expand the system functions by users.

2. A Supporting Library of MATLAB

I've developed a supporting library of MATLAB, which provides some extra functions for general popurse. All functions are written in standard MATLAB system format, and could be easily accessed from on-line HELP menu. As long as you have set your MATLABPATH to include my library path, you will be able to use all functions in my library.

For MATLAB users at CSR: path(path,'/users/chen/matlab/mylab')

For MATLAB users at GEO: path(path,'/home/h1/cjl/matlab/mylab')

 

The following is the on-line help menu of my MATLAB library.

 


>> help mylab

 MATLAB functions developed by Jianli Chen.

   arrow      - To draw an arrow vector.
   as_fit     - To compute annual/semiannual amplitude and phase.
   BWpred     - Backward prediction filter.
   de_as      - Removing annual & semiannual signals.
   departsl   - Moving average with same length output.
   departure  - Moving average.
   depoly     - Removing a polynomial fit from a series.
   filtlif    - Forward and reverse digital filter.
   FWpred     - Forward prediction filter.
   imrsp      - Impulse Response
   inte       - Interpolate the missing code to a proper value.
   int_extrap - Conbined interpolation and extrapolation.
   legends    - Adding legend(s) on current figure.
   lpr        - Print figure with handle.
   MANXM      - 2-D (N x M) Moving Average Filter.
   mycolorbar - Draw colorbar with extended option (real scale).
   neepd      - Bandpass filter, 'no' end effect, 'no' phase difference.
   plotspec   - Plot FFT spectrum.
   setbold    - Set the bold face of title, label and axis number.
   setfont    - Set the fontsize of title, label and axis number.
   setscale   - Set the physical scales of the figure on the paper.
   settick    - Set the tick labels on/off for X and Y axis.

						Last updated: 10/14/97

3. Image Processing in MATLAB

The right is a UTCSSA (University of Texas Chinese Students and Scholars Association) logo I designed in MATLAB. This design won the second (actually the top) prize (the first prize was absent in the contest ).



Here (the right) is a logo I designed for the Shanghai Astronomical Observatory , Chinese Academy of Sciences. A picture of the dome for the 1.56 m optical telescope is embeded in the middle of the logo. This logo has a transparent background.

Another example is the Chinese icon I designed for the Shanghai Observatory Oversea Fellows' webpage.


 
 

Email: cjl@maestro.geo.utexas.edu

Last updated: January 20, 1999