Known problems in MATLAB Answers
At the present time, the following problems are known in MATLAB Answers itself:
- Symbolic output is not displaying. The work-around is to disp(char(EXPRESSION)) or pretty(EXPRESSION)
- Symbolic preferences are sometimes set to non-defaults
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For the last few days now, this page:
doesn't list anything under the "Explore MATLAB Answers" banner.
I've noticed it's been broken for a few weeks now where I'd get a list of suggested links, but the links at the bottom of the list wouldn't display properly. Now there's nothing.
I think I've seen the list of links flash for a split second when first opening the page (but not always).
Win 10, Edge.
Hi Paul. Thanks for reporting this issue to us. We are investigating on it.
It loads the summaries for me in Firefox ESR. Maybe browser-specific?
I recall occasionally having issues like that maybe a year ago, but I attribute that to how bad my network connection was at the time.
According to https://www.mathworks.com/matlabcentral/answers/2172128-ode45-not-able-to-solve-one-particular-ivp#comment_3319755 the file attachment problem has been fixed.
Previously wrong, repaired since then:
- @doc is presenting messed up text until something is selected
- Near the top of each Question is displayed a link of the most recent activity on the question. The link is normally clickable and takes you directly to the relevant contribution. But at the moment the link does not take you anywhere
Also previously wrong and repaired since then would be the issue with the mysterious variables in the initial workspace, which was shown to be repaired earlier today (16 Dec 2024).
With regard to:
- Symbolic output is not displaying. The work-around is to disp(char(EXPRESSION))
I prefer:
pretty(EXPRESSION)
It preserves the formatting.
Can/would you edit the top level post in this discussion to reflect all of the issues identified below and their current status?
I expect that every time I start to compose an answer or comment that the defaults (for everything) are active, and that when I click Run (or ctrl-enter) that the workspace "resets," i.e., as if I'm running everything in a fresh Matlab session, i.e., there is no memory between one Run, editing the code, and the next Run, and every Run starts with the defaults (and a clear workspace and a clear symbolic engine) in place.
However, I occasionally run into a problem on Answers where the Symbolic preferences (sympref) are NOT the default values when starting to compose an answer or when re-Run-ning the code. Usually, the problem is with the FloatingPointOutput being set to true, and I have force it to false with a call to sympref. A few minutes ago, I ran into the problem where the HeavisideAtOrigin did not start at the default value (1/2). As shown in the screen shot below, it starts at the non-default value of 1 and then only goes to the default value of 1/2 after I forcibly set the preference to the default. Needless to say, I was quite confused as to why I was getting unexpected results until I realized that I wasn't actually using default preferences. I guess the safest thing to do would be to always put sympref('default') before any symbolic code, as annoying as that may be.
Also, weirdly enough when I was playing around in the Answer shown below, I did once see the correct default value on the first call to sympref, but then hit ctrl-enter and got the result shown below.
I think I got FloatingPointOutput set once . My memory is fuzzy as to whether I ever got HeavisideAtOrigin to be anything other than 1/2. I haven't noticed any of the other preferences being mis-set.
In contrast, I have encounted i = [] several times.
I've been running into a new one today. Any file I try to attach for an example is made inaccessible by the uploading tool.
ls % why does it have a .html extension?
dir().bytes % it's an empty file
inpict = imread('inframe.png'); % obviously i can't use it
Note that if you click on the attachment link, the actual PNG file is accessible -- just not programmatically.
I too am unable to load data from a file that I attach with a paper clip, in Matlab Answers.
I happen to have reported the same kind of problem internally on Tuesday afternoon.
Ah good. At least I'm not going crazy.
I've also noticed some buggy behavior when trying to submit a question. Sometimes the main text entry form wont switch from disabled to enabled so you need to refresh or close the browser and navigate back to MATLAB Answers in order to input your question.
(Answers Dev) Hi @Clayton Allen, could you try clearing your browser cache if that happens again? Thanks,
Rena
Mysterious variables are in the workspace at the initiation of an answer or comment. Also here in discussions. The empty i is particularly problematic.
whos
Now fixed here and on Answers.
w = whos
Using "@doc:" does not list audioDeviceReader or audioDeviceWriter
Earlier today, "@doc:size" did not list size() at all -- it listed lots of other things where "size" was a keyword in the help summary but omitted all of the various size functions.
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