问题
I'm getting some new students soon, who will be writing MATLAB code. They're new to MATLAB, but they have experience coding in Java and C++.
I'm going to have them go through the Getting Started section of the MATLAB help. In addition, I want to give a small tutorial with the goal to prevent them from making some of the most common mistakes people make when switching to MATLAB (e.g. "MATLAB starts counting at 1"), and show them some features that they may not be aware of when coming from other languages (e.g. "you can subtract a scalar directly from an array, and for vectors, there's bsxfun").
What are the most important things I should tell them?
回答1:
Enough snippy comments, here's something of an answer too:
- The Matlab desktop: what all the windows are for, dragging code from the history back into the command window, the variable inspector, etc.
- Plotting: not just the plot command, but how to use the plot GUI tools, and how to create an M-file from a graphic.
- M-files for scripts and functions, and the key differences between them.
- M-Lint, the profiler.
- Use Matlab as a vehicle for teaching the perils and pitfalls of floating-point arithmetic.
- Getting help: at the command line, on the web, documentation, the file exchange, ...
- Set path and the current working directory.
- Importing data from files, exporting data to files, loading and saving.
That should be enough to keep them busy for an hour or so.
To clarify, I propose these topics to help you teach your students to avoid common Matlab errors including;
- Unproductive use of the tool, retyping commands which can easily be recalled from the history, using C (or Java) style file reading commands instead of uuimport, slowly typing scripts to draw graphics when Matlab can do it for you, wondering what all the little orange lines in the editor right margin mean and the squiggly underlines, trying to figure things out for themselves when the help facilities could tell them, tons of other stuff that many much more experience Matlab users have taken ages to learn.
- Floating point arithmetic is not real.
- and probably a lot of other stuff too.
回答2:
I agree with previous answers, but I'd say indexing is the first and the most important and complex concept in studying MATLAB. I saw many C programmers starting with MATLAB just write loops, a lot of loops, something ridiculous like
for i=1:10
a(i)=i;
end
instead of simple a=1:10;
.
So I'd suggest them to read about matrix programming concepts:
- How to create simple vectors and matrices
- Which variables can be used for indexing
- How to create and apply indexes
- Logical operations and functions, logical and numeric indexes (find function)
- Indexing right and left side of expression
- Difference between indexing numerical matrices and cell arrays
- How to use indexes as output from different functions, like sort, unique, ismember, etc.
- You cannot apply indexes to intermediate results
As for productivity, I would add that knowing how to use editor's cell mode is very useful.
回答3:
For those coming from C-family languages, the element-wise operators are new. It took me a couple of months to discover the ./
and .*
operators. Before that, I used to write for loops for element-wise operations. So perhaps that's something that should be pointed out.
回答4:
With respect to unexpected or non-intuitive MATLAB features that may cause them confusion, there are some good pointers in this question:
- Corner Cases, Unexpected and Unusual MATLAB
With respect to cool time-saving/efficiency tricks, this other question has some nice examples:
- What are your favourite MATLAB/Octave programming tricks?
And for a few potentially more advanced topics, you can refer to the answers to this question:
- MATLAB interview questions?
Now for my $0.02. Based on the sorts of questions I've seen asked most frequently on SO, I'd say you will want to make sure they have a good understanding of the following concepts:
- Reading and writing data files of different formats, such as using CSVREAD, DLMREAD, TEXTREAD, FREAD, FSCANF, LOAD, and all their write equivalents.
- How to deal effectively with cell arrays.
- The different image formats, how these are represented, and how to modify them (which will involve a discussion of various data types and how to deal with multi-dimensional arrays).
- How to use handle graphics to control the appearance of various graphics objects.
And here are some neat features that are already implemented in MATLAB that may save them some time and effort:
- Functions for performing various array operations, like KRON, DIAG, and TRIU.
- Functions to create specialized matrices, like HANKEL and TOEPLITZ.
- Predefined dialog boxes, like UIGETFILE and INPUTDLG.
回答5:
MATLAB is conceptually in some ways very different from other languages you mentioned:
- cells are used were Java uses upcasting
global
andpersistent
variables arestatic
in Java- gui handles being just numbers of type
double
- nested functions are closures, neither Java nor C/C++ has such feature
- seldom used
private
and @TYPE folders for visibility scoping - array handling tricks
- very easy interoperability with Java/COM/.Net using MATLAB syntax
- variadic function arguments, handling of function arguments with
varargin
/varargout
- memory management
来源:https://stackoverflow.com/questions/2691569/matlab-tutorial-for-programmers