Subject: The MATLAB Digest; Volume 6, No. 1 Date: Mon, 9 Mar 1998 19:27:21 -0500 (EST) From: The MathWorks Reply-To: matlab-digest-owner@mathworks.com The MATLAB(R) Digest is The MathWorks electronic news bulletin for MATLAB Access members. You can expect to receive it at the end of each quarter. To remove yourself from this mailing list, send e-mail to mailto:access@mathworks.com. Type "Unsubscribe Digest" in the subject line and your name and MATLAB Access number in the body of the message. ======================================================================= The MathWorks MATLAB Digest March 1998 Volume 6, number 1 ======================================================================= Table of Contents ----------------------------------------------------------------------- 1. Technical Examples & Tips 2. User Contributed M-Files 3. Product Releases: MATLAB(R) 5.2 and Simulink(R) 2.2 4. MATLAB Based Books: New Titles 5. Sneak Preview: pre-release product usability input ======================================================================= (1) Technical Examples & Tips (a) "Electrohydraulic Servo Control" by Stan Quinn [mailto:squinn@mathworks.com] This article entitled "Electrohydraulic Servo Control" introduces an example in which Simulink and Stateflow(TM) are used to create a simulation model for a hydraulic servomechanism. The hydraulic servo is controlled by a pulse-width modulated (PWM) solenoid. This mechanism could be used as a system in an industrial or manufacturing setting or as a subsystem controlling the position of a valve in an aerospace or automotive application. The magnetic, hydraulic, and mechanical components and the control law are represented in Simulink while the electronic circuit that interfaces the PWM waveform to the solenoid is best modeled in Stateflow. The article explains the principles of the physical situation, and presents the equations that represent the system. It shows how to proceed from the physical equations to the Simulink block diagram. Once the Simulink model has been completed, we run the simulation, analyze the results, and draw conclusions from the study. "Electrohydraulic Servo Control" is available at http://www.mathworks.com/publications/digest/electro/ (b) UINT8 Data Type for Image Processing In the Image Processing Toolbox version 2.0 a new data type, uint8, was introduced to help minimize the amount of memory necessary for the storage of image data files. The data in the uint8 arrays is stored as 8-bit unsigned integers and therefore requires one-eighth as much memory as a double array. MATLAB provides limited support for operations on uint8 arrays. IMREAD reads images into MATLAB as uint8 arrays, and the IMAGE and IMAGESC functions can display uint8 images. For a full listing of the operations that can be performed on uint8 arrays please refer to http://www.mathworks.com/support/solutions/v5/8914.shtml (2)User Contributed M-Files (a) Isosurface package for MATLAB version 5.0 Created by Lennart Bengtsson [mailto:tfylb@fy.chalmers.se] 11/3/97 The M-files and MEX-files in this tar file provide isosurface support in MATLAB. An isosurface is the 3-D analogue of a 2-D contour line and is defined by the solution of the equation f(x,y,z) = constant. Isosurfaces are very useful for visualizing 3-D data. ftp://ftp.mathworks.com/pub/contrib/v5/graphics/equisurf/ (b) Kepler Problem for Orbit Intersection Created by Russ Sexton [mailto:russ.sexton@pobox.tbe.com] 12/29/97 This is a solution for the Kepler problem for orbit insertion. Given a burn out velocity and a flight path angle, the apogee of the orbit and the circular orbit that can be achieved with one burn at apogee will be calculated. The delta-velocity for circularization is also plotted. Several other planets besides Earth are included and you can simply adjust the initial parameters to perform orbital analysis of several planets in our home solar system. ftp://ftp.mathworks.com/pub/contrib/v5/model/morbit.m (c) Viewing and Printing Sound Spectrograms Created by Dave Mellinger [mailto:dkm1@cornell.edu] 9/3/97 Osprey, version 1.3.1, is a program for viewing and printing spectrograms of sound files. It allows you to change various parameters that affect the computation and display of spectrograms, including the time/bandwidth tradeoff, the window type, and display brightness. It computes and caches spectrogram values on demand, minimizing computation time. It also allows manual logging of information about the sound (time, frequency, energy, etc.) for use in acoustic analysis. ftp://ftp.mathworks.com/pub/contrib/v5/signal/osprey/ The user-contributed archive is a service to the MATLAB community -- a place where MATLAB users can communicate ideas to one another. It is not a depository of MathWorks approved software; no warranties, expressed or implied, are made by The MathWorks that the M/MEX files contained in the archive are error free. Use of these programs is at the user's own risk and The MathWorks disclaims all liability for injury or damage that may result from their use. Visit http://www.mathworks.com/ftp/ for more user contributed M-Files and for submission instructions. (3) Product Releases Release 10 is now shipping. http://www.mathworks.com/products/10highlight.shtml Some highlights include: MATLAB 5.2 http://www.mathworks.com/products/matlab/newfor52.shtml Simulink 2.2 http://www.mathworks.com/products/simulink/ The MATLAB 5 compatible Compiler extends MATLAB by providing automatic C and C++ code generation of M-file programs directly from MATLAB. The MATLAB C and C++ Math Libraries make the core mathematical capabilities of MATLAB available outside the MATLAB environment. http://www.mathworks.com/products/compilerlibrary/ Power System Blockset 1.0: The new Power System Blockset for MATLAB 5.2 and Simulink 2.2 allows you to model and simulate the generation, transmission, and consumption of electrical power within Simulink. http://www.mathworks.com/products/powersys/ Control System Toolbox 4.1: New features are included to support an interactive environment for classical and modern control system design, analysis, and modeling. Features include the LTI Viewer (analysis tool) now accessible from Simulink and the Root Locus Design graphical user interface. http://www.mathworks.com/products/control/ DSP Blockset 2.2: New features include filter realization wizard for constructing filters with different architectures, frame-based processing, and new blocks for variable delays, discrete cosine transform and spectral estimation. http://www.mathworks.com/products/dspblockset/ Neural Network Toolbox 3.0: Recent enhancements include modular network representation, new network types and training algorithms, pre- and post-processing functions, and enhanced Simulink support. http://www.mathworks.com/products/neuralnet/ Signal Processing Toolbox 4.1: Recent additions include enhancements to filter designer, additional spectral analysis methods, new algorithm features including additional filter design methods and multirate filter bank implementation. http://www.mathworks.com/products/signal/ Current information on all products can be found at http://www.mathworks.com/products/ (4) MATLAB Based Books: New Titles "DSP First: A Multimedia Approach" is a hands-on multimedia package for learning about DSP applications, multimedia signals, and MATLAB. "Mastering MATLAB 5: A Comprehensive Tutorial and Reference" provides a 'learn while doing' approach covering all aspects of MATLAB 5. "Mastering SIMULINK 2", both a tutorial and a reference, covers all of the important capabilities of Simulink 2, including subsystems, masking, callbacks, and S-Functions. "Modern Control Systems, 8e" presents a control engineering methodology that stresses physical system modeling and practical control system designs. The MathWorks supports authors of books that incorporate MATLAB, Simulink, toolboxes, or blocksets in the text. For more information about the MATLAB based book program visit http://www.mathworks.com/books (5) Sneak Preview - pre-release product usability input on a new Integrated Control Design Environment ('ICDE' is only a preliminary name for this product. The actual name of the product when it is officially announced may be different. We apologize for any confusion this may cause.) MATLAB Access members are invited to give pre-release product feedback online. The Integrated Control Design Environment (ICDE) provides an integrated GUI-based environment for design, analysis, and simulation of control systems. This environment will streamline the control design process, allowing you to easily compare different design techniques. We are in the process of designing the tool and appreciate your input. Visit: http://ngate.mathworks.com/mla/flow.nsf/flow ===================================================================== You can access our Technical Support solutions database 24 hours a day at http://www.mathworks.com/support for the fastest answers to your technical problems. ===================================================================== The MATLAB Digest is The MathWorks electronic news bulletin for MATLAB Access members. For a complete listing of MATLAB Access benefits, visit: http://www.mathworks.com/mla/benefits.shtml To remove yourself from this mailing list, send e-mail to mailto:access@mathworks.com. Type "Unsubscribe Digest" in the subject line and your name and MATLAB Access number in the body of the message. To notify The MathWorks of both postal and e-mail address changes, send e-mail to: mailto:access@mathworks.com Include your name and MATLAB Access number in the body of the message. MATLAB Digest questions and comments can be sent to: mailto:digest@mathworks.com Please provide your MATLAB Access number when you contact us. (c) 1998 by The MathWorks, Inc. All rights reserved. MATLAB, Simulink, Handle Graphics, and Real-Time Workshop are registered trademarks, and Stateflow and Target Language Compiler are trademarks of The MathWorks, Inc. Other product or brand names are trademarks or registered trademarks of their respective holders.