Some issues I've been having with worksheets

[Robert Jacobson]

I have experienced disappearing plot output. I evaluate, say,

plot(sin(x^2)*exp(-x), [x, 0, 7])

and the next time I open the worksheet, say, the output is replaced with a question block (404 error). I cannot reliably reproduce the issue. It can happen while I have the worksheet open, or after the third time I open the worksheet--I can't see a pattern.

Over the last two days I've had strange things happen when I evaluate cells. The cell will appear to evaluate but produce no output, or the spinner will spin forever. There is never an error message. Restarting the worksheet process does not solve the problem. This has been happening over the last couple of days, so maybe it's because you've been working on upgrading the server. Sometimes (maybe always?) the output appears if I close and then reopen the worksheet. Again, I can't reliably reproduce this.

The question mark operator gives "SyntaxError: unexpected EOF while parsing" instead of documentation.

How are public projects discoverable? Can I share a link to a public project somehow? Is there a directory of public projects?

Regards,

Robert

[William Stein]

On Sun, Jun 30, 2013 at 12:58 PM, Robert Jacobson <rljac...@gmail.com> wrote:
> I have experienced disappearing plot output. I evaluate, say,
> plot(sin(x^2)*exp(-x), [x, 0, 7])
> and the next time I open the worksheet, say, the output is replaced with a
> question block (404 error). I cannot reliably reproduce the issue.

Hi,

I'm fully aware of this, and simply haven't had the time to address
it. What is happening behind the scenes is somewhat
technical/complicated/interesting. First, what happens now is that
when you generate the plot, a link with a 10-minute time to live is
generated. After 10-minutes, that link is no longer valid, hence the
broken link you see in the browser. You probably don't reliably
always get the broken link because of browser caching.

The fix is for me to implement something that on save of a worksheet
copies all of these temporary links to permanent ones. The cool
thing about these permanent links is that you can copy/paste the text
of your worksheet around to other projects, other people can copy
them, etc., and the images in them will just work without any need to
regenerate them. This is particularly nice if you're using git to
keep track of worksheets.

I want to have some sort of trigger for saving the images to a
longterm store in the database, since when using interacts (say) there
are lots of short-term images, that should not be saved.

Motivated by your question, I'm moving this issue to the top of my todo list.

> Over the last two days I've had strange things happen when I evaluate cells.
> The cell will appear to evaluate but produce no output, or the spinner will
> spin forever. There is never an error message. Restarting the worksheet
> process does not solve the problem. This has been happening over the last
> couple of days, so maybe it's because you've been working on upgrading the
> server. Sometimes (maybe always?) the output appears if I close and then
> reopen the worksheet. Again, I can't reliably reproduce this.

1. Are there any errors in the Javascript console log (in the browser)?

2. What browser/os combination are you using?

3. How's your internet connection?

There are things I need to do to make code evaluation in worksheets
more robust -- everything is done via synchronization, and there are
edge cases that cause trouble, especially when something flaky happens
with the internet connection. (I implemented all the synchronization
stuff from scratch fairly recently.)

> The question mark operator gives "SyntaxError: unexpected EOF while parsing"
> instead of documentation.

That's due to me not having implemented that yet. What does work is

foo?[tab key] or foo([tab key]

and

foo??[tab key]

> How are public projects discoverable?

This is not implemented yet. In the future there will be an "Explore"
tab between "Help" and "Projects", where you'll be able to browse
popular public projects, search by keywords, etc.

> Can I share a link to a public project somehow?

Not yet, unfortunately. Coming soon!

>
> Regards,
>
> Robert
>
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--
William Stein
Professor of Mathematics
University of Washington
http://wstein.org

[William Stein]

On Sun, Jun 30, 2013 at 3:43 PM, William Stein <wst...@gmail.com> wrote:
> On Sun, Jun 30, 2013 at 12:58 PM, Robert Jacobson <rljac...@gmail.com> wrote:
>> I have experienced disappearing plot output. I evaluate, say,
>> plot(sin(x^2)*exp(-x), [x, 0, 7])
>> and the next time I open the worksheet, say, the output is replaced with a
>> question block (404 error). I cannot reliably reproduce the issue.
>
> Hi,
>
> I'm fully aware of this, and simply haven't had the time to address it.

And, as I mentioned in another post, this should now be fixed.

Be sure to (aggressively?) refresh your browser when viewing
https://cloud.sagemath.com to get the latest update.

[Robert Jacobson]

On Sunday, 30 June 2013 18:43:44 UTC-4, William Stein wrote:

On Sun, Jun 30, 2013 at 12:58 PM, Robert Jacobson <rljac...@gmail.com> wrote:
> Over the last two days I've had strange things happen when I evaluate cells.
> The cell will appear to evaluate but produce no output, or the spinner will
> spin forever. There is never an error message. Restarting the worksheet
> process does not solve the problem. This has been happening over the last
> couple of days, so maybe it's because you've been working on upgrading the
> server. Sometimes (maybe always?) the output appears if I close and then
> reopen the worksheet. Again, I can't reliably reproduce this.

1. Are there any errors in the Javascript console log (in the browser)?

2. What browser/os combination are you using?

3. How's your internet connection?

There are things I need to do to make code evaluation in worksheets
more robust -- everything is done via synchronization, and there are
edge cases that cause trouble, especially when something flaky happens
with the internet connection.  (I implemented all the synchronization
stuff from scratch fairly recently.)

I can no longer reproduce this and am beginning to suspect user error. :)  I'll return with more details if it happens again. For the record: Safari 6.0.5 on Mac OS X 10.8.4 with a solid internet connection. I didn't think to check the javascript console at the time.

Regards,

Robert