다음에 대한 결과:
What should you post where?
Next Gen threads (#1): features that would break compatibility with previous versions, but would be nice to have
@anyone posting a new thread when the last one gets too large (about 50 answers seems a reasonable limit per thread), please update this list in all last threads. (if you don't have editing privileges, just post a comment asking someone to do the edit)
This topic is for features you would like to see for the MATLAB Answers facility itself, and also for bug reports about the MATLAB Answers facility.
This topic is the follow on to the first Wish-list for MATLAB Answer sections and second MATLAB Answers Wish-list #2 (and bug reports). Those grew large enough to become unwieldy; and Mathworks has made enough changes to make a number of the past points no longer of relevance. More recently there was the limited purpose New design of the forum - grey on white which turned into a bug and wish list; I have renamed that for continuity.
I suggest one wish (or bug report) per answer, so that people can vote their wishes.
I've opened MATLAB Answers this morning and found the new design.
The field for typing the "Body" does not consider the font settings of my browser anymore, such that my preference of sans-serif fonts is ignored. In addition the text color is a medium gray, which is hard to read for me due to the too light contrast.
Blank lines in the code let two separate code boxes appear. This makes almost all code, I've posted in the forum, invalid. It has been discussed repeatedly, that blank lines in the code confuse the indentation of the display in the forum and that this is a really bad idea. But instead of improving this, it is made severely worse now.
The new design contains even more white space, such that standard questions cannot be answered without extensive vertical scrolling. It is a very bad drawback, that I cannot see the question while I type the answer.
There is still no suggestion to use a proper code formatting, such that I have to spend 20% of my forum time typing corresponding comments as before.
But I'm coming back to the most important problem for me: It is a physical problem for me to read the low contrast grey on white text. Does anybody know a tweak or CSS trick to increase the readability?
TMW, please take into account that this new design is physically hard to read for people without young and 100% perfect eyes. This is very annoying for me.
Splitting code blocks at white lines is simply a bug. I cannot imagine why this error has not been detected before the new design has been published. The argument, that TMW is extremely conservative with changes in the forum to ensure a stability does not convince me anymore.
[EDITED] The box around the thread, the preview box, the boxes for preformatted text and code have a grey background now. So some text is even medium grey on light grey.
I'd be glad if the designers refocus on the purpose of the forum. Whatever this purpose might be, the optical reception of the characters is fundamental.
Some of Matlab's toolbox functions are affected by magic strings or magic numbers, which are strings or numbers with a deeper meaning besides the normal value. Both are considered as bad programming patters, because they provoke confusions, when the magic keys appear with the normal meaning by accident. See http://en.wikipedia.org/wiki/Anti-pattern
Example 1:
clear('myVariable')
clear('variables')
While the 1st clears the variable myVariable, the later clears all variables. Here 'variables' has a meta-meaning. The problem appears, when 'variables' is an existing variable:
a = 1;
variables = 2;
clear('variables')
disp(a) % >> 1
Only variables is cleared, which cannot be understood directly when its definition is 1000 lines before.
Example 2:
uicontrol('String', 'default')
This creates a button with the empty string '' instead of the expected 'default', because this is the magic string to invoke the default value get(0, 'DefaultUIControlString'). The same concerns properties of other graphic objects also, e.g. the 'name' property of figure or the string of uimenu. There is a workaround which allows the user to display 'default': Simply use '\default'. Unfortunately this is doubled magic, because in consequence it is impossible to display the string '\default'. Obviously a bad idea.
Example 3:
Graphic handles are doubles (although gobject of the new R2013a seems, like this is subject to changes? [EDITED: Yes, it changed with HG2 in R2014a]). But then a handle can be confused with data:
a = axes; % e.g. 0.0048828125
plot(a, 2, '+')
But you cannot draw the point [0.0048828125, 2] by this way, because the 1st input is considered as handle of the parent. Here all possible values of handles are magic. Collisions are very unlikely, but there is no way to avoid them reliably - as long as handles have the type double.
Question:
Which functions are concerned by magic values? What are the pitfalls and workarounds?
This topic is for features you would like to see for the MATLAB Answers facility itself, and also for bug reports about the MATLAB Answers facility.
This topic is the follow on to the earlier Wish-list for MATLAB Answer sections. That topic grew large enough to become unwieldy; and Mathworks has made enough changes to make a number of the past points no longer of relevance. There was also a more limited purpose <http://uk.mathworks.com/matlabcentral/answers/216662-new-design-of-the-forum-grey-on-white-wish-list-3-bug-reports
I suggest one wish (or bug report) per answer, so that people can vote their wishes.
Hello all,
Please explain good MATLAB programming practice methods. It will help to the guys who are new to programming like me.
Previously I used
for i=1:10
after following some suggestions from this answers pages I learnt to use
for i1=1:100
This is the good way to write programs.
Like this, as a professional programmer, please mention some good programming practice techniques.
It will useful to all!
Now, I am still a novice when it comes to programming. I believe MATLAB is definitely a great programming tool, one that I can play with, particularly, when I have free time.
I would love to hear from all answerers, what are the ways that can make one proficient in this field?
Don't be shy, what was your matlab learning curve, how many years or months, what were the difficulties to begin with.
I think that the answers would be most valuable for new users, maybe you can also tell us the tricks that allowed you to master some parts or all matlab.
Now it's your turn...
I love MATLAB. It is so quick and easy to write software to do what you want. It has excellent debugging and profiling tools. It is cross platform, making code easy to share (assuming the other people have forked out for the not-so-cheap license). It has interfaces to other software.
However, there are some things about it that irk me. I'd like to hear from other people what things annoy them about MATLAB.
---------------------------------
Because this thread has become so large it is slow to load and navigate. Please post new answers in the second thread.
---------------------------------
What is the best way to learn MATLAB at home without a tutor?
As asked by Vieniava in "How to make a list of user's reputation?", some of us came up with interesting ideas on how to fill an updated list with the reputation scores of the contributors to Answers.
I took the initiative to compile a public list of users with meta info:
- position (desc ordering by reputation)
- id
- nickname (truncated to fit the page)
- reputation
- # of comments
- # of questions asked
- % accept rate
- # of posts answered
- # of accepted answers
The code used to compile the list is available at the bottom.
EDIT
TMW team implemented a page with the metascores: http://www.mathworks.com/matlabcentral/answers/contributors
Please refer to it and congrats to the team!
Use this function to retrieve info from the link above:
function [metainfo, elapsedTime] = metainfo(type,order)
% METAINFO - Retrieve metainfo on contributors to www.matworks.com/.../answers
%
% METAINFO Retrieve data sorted by reputation in descending order
%
% METAINFO(TYPE,ORDER) Specify TYPE and sorting ORDER as
% type : 'reputation'
% 'questions'
% 'answered'
% 'accepted'
%
% order: 'asc'
% 'desc'
%
% Examples:
%
% % Standard call (rep, disc)
% info = metainfo;
%
% % Sort by question answered in descending order
% info = metainfo('an','d');
%
% See also: URLREAD, REGEXP
% Author: Oleg Komarov (oleg.komarov@hotmail.it)
% Tested on R14SP3 (7.1) and on R2009b. In-between compatibility is assumed.
% 28 feb 2011 - Created
tic
% Check # inputs
error(nargchk(0,2,nargin))
% Retrieve inputs
if nargin == 0
type = 'reputation';
order = 'desc';
end
if ~exist(type,'var')
sortTypes = {'reputation','questions','answered','accepted'};
type = sortTypes{strncmp(type,sortTypes,numel(type))};
order = 'desc';
end
if ~exist(order,'var')
orderTypes = {'asc','desc'};
type = orderTypes{strncmp(order,orderTypes,numel(order))};
end
% Build url string
url = ['http://www.mathworks.com/matlabcentral/answers/contributors?'...
'dir=' order '&sort=' type '&page='];
% First read
[page, ok] = urlread([url '1']);
% Catch number of pages to read
if ok
totcon = regexp(page,'>1 - 50 of (\d+)','tokens');
totcon = dataread('string',totcon{1}{1},'%d');
nPages = ceil(totcon/50);
else
error('Cannot read ".../contributors?page=1"')
end
% Loop over contributors pages
metainfo = cell(totcon,7);
metainfo(1:end,1) = num2cell(1:size(metainfo,1));
for p = 1:nPages
if ok
endpos = 50*p;
% Id, Rep
expr = '><a href="\/matlabcentral\/answers\/contributors\/(\d+)';
data = regexp(page, expr,'tokens');
if 50*p > totcon; endpos = 50*(p-1)+numel(data); end
metainfo(1+(p-1)*50:endpos,2) = [data{:}];
% Nickname
expr = ['"Reputation: (\d+)">([\w\ ' reshape([repmat(92,1,137);33:59,61:64,91:97,123:126,161:255],1,[]) ']+)</a></h2>'];
data = regexp(page, expr,'tokens');
metainfo(1+(p-1)*50:endpos,[4,3]) = cat(1,data{:});
% Qcount, Ans, Acc
data = regexp(page, '<span >(\d+)</span>[A-z<>"-\s\/]+','tokens');
metainfo(1+(p-1)*50:endpos,5:7) = reshape(cat(1,data{:}),3,[]).';
else
error('Metainfo import stopped. \nCannot read ".../contributors?page=%d"',p)
end
[page, ok] = urlread([url sprintf('%d',p+1)]);
end
% Convert to doubles
metainfo(:,[2,4:7]) = cellfun(@str2double,metainfo(:,[2,4:7]),'un',false);
elapsedTime = toc;
This topic (which was not started by Mathworks) is for features you would like to see for this MATLAB Answers facility.
I suggest one wish per answer, so that people can vote for individual wishes.
What should you post where?
Next Gen threads (#1): features that would break compatibility with previous versions, but would be nice to have
@anyone posting a new thread when the last one gets too large (about 50 answers seems a reasonable limit per thread), please update this list in all last threads. (if you don't have editing privileges, just post a comment asking someone to do the edit)
