( 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 Zplane, 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 online
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 online 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  2D (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.


Last updated: January 20, 1999