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12:03 AM
Obviously, it is not the fastest thing on earth. If we do a 100 by 100 table, it takes a lot of time. But for now I'm only looking for the Mathematica concept of a Spreadsheet
12:16 AM
I can almost spreadsheet images. This is a new concept! I put one cell equal to an image, and then put a second cell equal do the first cell, but lighter. Just need to resolve small details with evaluation control...
12:29 AM
Lots of details needed: DynamicModule to keep the variable alive, data versus formating data structure; sliders and other dynamics inside cells; inport from Excel (a simple parser should be easy); Automatic transformation of a Mathematica spreadsheet into a customized app interface (taking out non used cells and exporting into a CDF)...
1 hour later…
1:31 AM
should this
Q: Why are recent entries in Windows Start Bar never up-to-date

Ernst StelzerRunning Windows (5,6,7), I have always pinned Mathematica to the Start Bar. This feature offers the Recent files for a quick load. However, the list has never been up-to-date. By never I mean, with any version of Windows I have used over the years and with any version of Mathematica up to vers...

really be closed and downvoted? OK it's expressed as a rant, but it's a genuine question and is in fact answered
I'd go for reopening (@rm-rf ?)
1:53 AM
@rcollyer so I gather your defence is today/tomorrow? best of luck!
2:04 AM
@P.Fonseca not sure how relevant this is but there is a third party app called BestViewpoints (or similar?) which looks like it is a spreadsheet like app built with Mathematica. ...if it is any good may be better than reinventing the wheel?
2:49 AM
@acl (I didn't vote either way) I just don't see it as an mma specific question, as it's more an operating systems 101 question — each app always shows the list of files opened from within it. The confusion might've arisen from not thinking about the explorer/finder as apps themselves. If not NC, I'd probably say TL. In any case, if people want to reopen, I won't stop it.
@rm-rf actually in that case I thought the question worthwhile because I finally realized what the difference is between which "recently opened" files are shown by the Dock menu and mathematica itself (and quicksilver/launchbar in OS X)
but maybe it is too localized
Let me see if I can find a home for it on Super User...
@rm-rf I pinged you as the last person voting to close and a moderator (you volunteered, didn't you :) )
yes superuser sounds better as this amounts to a question on what is shown in the recently opened lists in various places
@acl I don't mind being pinged anytime for any reason, regardless of whether I voted or not :) I might not always respond right away...
Q: Why are recent entries in Windows Start Bar never up-to-date

Ernst StelzerRunning Windows (5,6,7), I have always pinned Mathematica to the Start Bar. This feature offers the Recent files for a quick load. However, the list of files has never been up-to-date, i.e., I can never access my most recently opened Mathematica files. I would agree that it is not very importa...

We'll see if they reject it.. if they do, then it'll come back here and remain closed (as OT).
@rm-rf oh no.... I hovered my cursor over my name in the comment there, and I DON'T EXIST! oh dear.
terrible :)
3:04 AM
Must've gotten lost in the warp zone
@rm-rf as an aside, how's the sublime text thing going? given up? (I spent most of the last few days using it for both coding and finalizing papers, which is why I'm asking)
@acl Oh, I haven't used it actively... I got busy the past few days and holed up in the MATLAB IDE :)
3:30 AM
@AndyRoss How's it going?
4:07 AM
@acl tomorrow at 3 pm local time. I'm going to be flambeed. But, I will survive: either I will have initials, or I won't. It is mostly out of my hands now.
4:30 AM
Do you guys think it's safe and a good enough idea to just add new properties to TemporalData, or that I should do it in a dynamic environment as leonid usually suggests?
In the meantime, dynamic environment it is
@Rojo I think it's a bad idea, but I'm interested to know what properties you want to add.
@BrettChampion What a bad idea, adding them without a dynamic environment or adding them at all?
Well, given that now there's a wrapper for time-value pairs, I see myself using it a lot for the special simple case of equally spaced times
For those cases, I could use a "TimeStep" property, and a "TimeExtension" (or some other name) for the length of the domain, the "TimeStep" times the "PathLength"
@Brett I missed that message, I wasn't around unfortunately :(
@Szabolcs I was going to ask how you like Indiana so far.
4:45 AM
@BrettChampion Haven't been outside of South Bend yet, but I like it here
Should take the time to visit Chicago finally
@Rojo The main concerns (off the top of my head) are how it would work with saving the notebook and whether it would kill some of the performance. Andy is the expert on TemporalData, though.
@BrettChampion I see... Well, it's a property, so it would get evaluated before saving the notebook just like other functions I think. I'll ask andy
@Szabolcs I mean that, if you take TemporalData[{2, 1, 6, 5, 7, 4}, {{1, 2, 5, 10, 12, 15}}] and evaluate it, you get something that looks like TemporalData[Panel[1]]. But this actually contains all the original information, even if you kill the kernel. I'm guessing that it wouldn't preserve your custom properties, however.
@Szabolcs Do you have a car? (Though driving in Chicago can sometimes be intimidating for people who aren't used to it.)
@Szabolcs And you should get over to see the dunes at some point, though that's more of a warm weather activity.
2 hours later…
6:55 AM
@MikeHoneychurch Thank you for the info. Last Time I saw it, it was just a "view". I want the interactive building of the calculation.
Going to have a look again. But I think it is mainly based on data analysis, and not on free building (plus, it is not free).
2 hours later…
8:56 AM
@EliLansey that fixed it for me. Weird that disabling internet access doesn't also do this. I guess this is a bug.
I think the issue may be partly because I have IPv6 set up but no IP address or any routes configured, so it times out. Looks like this check is done asynchronously using the new libcurl functionality added in M9.
9:35 AM
Finally installed mma9. But it set mm8 to trial mode as well... :/
At least no BOSD this time
Fixed it
(just switched the lines in the mathpass file)
10:33 AM
Linked to this question: mathematica.stackexchange.com/questions/14658/… there is a small app for windows (called insideClipboard) that shows all the different formats that were saved to the clipboard. It would be nice to have inside Mathematica an import converter, that is, a tool that reads the different formats available, and for each one, suggests different past possibilities.
11:23 AM
Is there a simple way to center the ouput?
11:38 AM
@Giovanni of what? where?
@rcollyer nah don't worry about it. it'll be fine. and anyway it's out of your hands, so...
@acl In Mathematica output, inside the notebook. I would like to center the output of an expression, using code.
@Giovanni CellPrint[Cell["abc", "Text", TextAlignment -> Center]]
but probably that's not what you want
@acl Thanks, I'll give it a try.
@Giovanni I mean if you're more specific then maybe I can help. But this as it is is not very useful
@acl I managed to center the output using the Format > Text Alignment menu option, but if I clear all the output, I have to do it again. So I thought if I could set this inside my code.
Output of a cell.
11:52 AM
@Giovanni well, what I sent centers the string "abc". if you want to center something else, try defining pc = CellPrint[Cell[ToString@#, "Text", TextAlignment -> Center]] & then eg pc[132]
but this won't work for graphics (for instance) or typeset formulas since it converts to strings
you could assign it to $Post to do this for everything, but that's not a good idea the way I wrote pc
I guess I mean, you really do need to be more specific.
and maybe ask it as a question on the site if you want a robust solution
I don't know how I could specify more, sorry. But yes, I'll search a little more, and maybe ask on the site. Thanks
@Giovanni I mean, what sort of thing do you want to center? graphics? text? typeset equations? etc
@Giovanni actually try $Post = CellPrint@Cell[ToBoxes@HoldForm@#, TextAlignment -> Center] &
then Plot[Sin[x], {x, -5, 5}] or TraditionalForm[Cos@x/Sqrt[1 + x^2], x] seem to work
no guarantees though
(it prints Null if there is no output)
@acl I want to center tables. Inside the tables are Strings e and equations.
Your code worked, but turned Strings into this "string"
12:07 PM
@Giovanni well I don't know what you mean by a table... Probably best to ask this on the main site (try to be specific so people can answer your actual question, rather than randomly trying to guess as I did :) )
@acl A table using TableForm. hehe. right. Thanks
1:07 PM
Hello i have a question but i don't really know how to search for it: I want a table with elements a1[x],a2[x].... of course Table[ai[x], {i, imax}] doesn't work. How do i do that properly?
I think it's not really the right level for a "real" question on the frontpage ;)
@ungerade hello! I agree, it's not really a front page question, so thanks for asking here. How about this: Symbol["a" <> ToString[#]][x] & /@ Range[imax] ?
@OleksandrR. Thx, works! I thought there is some easier way ;) like "a\i" which says you mean "i" the variable! But thanks anyway!
@ungerade afraid not. Actually what you want to do is quite unusual in Mathematica. A more typical way to achieve it would be to have a[i][x] or a[i,x], in which case you can use Table.
Or, indeed, Through@Array[a, imax][x].
@OleksandrR. that's how i did it ;). But when i print the eqations they look very unnatural for a non-mathamatica guy
@OleksandrR. that's how i did it ;) was referencing to your first comment a[i][x]
@ungerade how about a /: MakeBoxes[a[i_], form_] := InterpretationBox[SubscriptBox["a", i], a[i]] first before using Through@Array[a, imax][x]?
1:22 PM
@OleksandrR. let me see what that does ;)
Wow! Very nice! It works but i get when i just enter:
MakeBoxes[a[i_], form_] := InterpretationBox[SubscriptBox["a", i], a[i]]
Through@Array[a, i][x]
Array::ilsmn: "Single or list of non-negative machine-sized integers expected at position 2 of Array[2,i]."
Array::ilsmn: "Single or list of non-negative machine-sized integers expected at position 2 of Array[2[x],i[x]]. "
(but it works very nice, i think i need some time to understand it properly as a mathematica beginner, but is very nice to see how one can do that)
@ungerade yes, you need to give an integer in that position (corresponding to your imax). BTW, you really should use TagSet like I showed and not set a DownValue on MakeBoxes directly.
1:38 PM
@OleksandrR. alright ! Very nice! Thx for the support.
@ungerade you're welcome!
Like the new mma9 interface uplift. It's snappy and useful.
Does anybody know if this is on purpose (that the Image3D is blurry?) Mathematica graphics
2:29 PM
@Ajasja yes, it's on purpose. The blurring comes about because the blocks are semitransparent. From different angles it's more or less blurred.
3:17 PM
@Rojo, there are some undocumented properties for TemporalData that can be obtained via "DeveloperProperties" I don't claim that these are tested or won't change so use with caution. There is a "MinimumTimeIncrement" property that gets that time step you are after for uniformly spaced data.
@Rojo as for adding properties to TemporalData. You can add basic key-value type properties via MetaInformation. This mechanism is a bit experimental so I'm keen to know how it works for you and how you end up using it.
@OleksandrR. what ended up working for you?
3:41 PM
@EliLansey disabling checking for documentation updates. But, in addition to having disabled internet access.
Hi; something always wondered about, how does one know what was changed, in a question/answer page? i.e. sometimes I see that a question was updated, but how do I know what was added? i.e. is there a way to highlight or see what was changed say from some time ago? like question mathematica.stackexchange.com/questions/18/… changes all the time, but I have no idea what was added to it since there is no marking or anything
Anyone notice that saving big notebooks in M9 is way slower than in M8?
@NasserM.Abbasi click on the revision time. For instance, mathematica.stackexchange.com/posts/259/revisions
@OleksandrR., where is this "revision time" link? I never saw such one. I am looking now at a question, and I do not see such an option?
@NasserM.Abbasi the bit that says "edited x minutes ago by ..." is a hyperlink that takes you to the editing history for the question.
Oh, I see. So I have to go down look at the bottom of EACH answer to see if that is the latest change on the page, and if so, click on it to see what has changed. So if there 10 anwers on the same page, I would not do which one has added something, unless I look at the time stamp of each. It is easier with newsgroups, as they are threaded, so one always knows which is the latest activity.
3:54 PM
@NasserM.Abbasi there may well be another way but that's how I've always done it. I seem to remember there being more ways to look at this with moderator tools available (which you aren't far from).
@NasserM.Abbasi maybe. A lot of crap tends to get interspersed into the messages in newsgroups so actually I often find it rather hard to follow. Especially when people (such as Alexei Boulbitch) don't quote what they reply to but just insert their comments at the end... very hard to tell who is replying to what in that case.
@NasserM.Abbasi actually you are farther than I thought. I was going by the 9394 I see under your name on chat.
@OleksandrR., this is a function of which usenet reader you are using. some have more features than others. One can always look at things as threaded, or by time, and possibly in many other ways. (but forums like are nicer only because one can edit a message (fix typos) and add things to it later, which is not possible on usenet)
Dumb question: Where is the preferences menu entry in Mathematica V9 under OSX 10.8?
@NasserM.Abbasi I don't think any newsreader will save you from the typical long thread that contains a mixture of top- and bottom-posting, sometimes quoted, sometimes not, with different quoting styles, weird posters' signatures, some messages posted by users with crappy clients like MS Outlook that quadruple-space the entire message...
4:02 PM
Cool.. it's gone! On my MacBook it's in the usual place. On my MacPro it's just gone ;-)
@halirutan Well on Win 7 the save button in the Save, Print and Option Inspector buttons are gone - fair is fair
![Mathematica graphics](http://i.stack.imgur.com/IN3G9.png)
Also, I have intermittent crashes when selecting text and pressing F1 - the help behaves erratically.
@YvesKlett Weird. Restarting everything and now I have it back. What the f***? It feels like I'm on Windows!
What comes next? A blue screen? Oh no, wait. It will definitely not be blue.. it will just show an apple.
how do I post images on chat?
@YvesKlett just put the link
Just post the URL
Or use the next generation uploader ;-)
Post the url as separate message!
;-) funny
4:08 PM
ahhhh... better :-)
@YvesKlett What exactly is wrong in the image above?
(Sorry, I never look at Windows windows)
I am used to this:
Mo´ buttons!
@halirutan yes, you are rather dogmatic about that, aren´t you?
@halirutan is there a new uploader?
one thing I really like in Mathematica is that it seems much more organized in terms on name space and packages. All names and functions start with Uppercase. And much easier to make packages. When I look at Matlab code, I have no idea which is a user function and which is a matlab function.
posted on December 05, 2012 by Wolfram Blog Team

Curious about Mathematica 9? You can see it in action in three free online events. Our experts will introduce you to new features in usability, computation, data manipulation, and visualization. Live Q&A sessions during each event will give you a chance to ask questions. Topics covered: Predictive Interface and Units: December 10, 1–2pm EST Get [...]

Limited seats? Fail.
Why don't they just use Google Hangouts?
4:20 PM
@Kiyura probably because it is pretty difficult to answer questions if you're inundated with thousands of users asking things like "hurr durr what's your favorite cheese"
You can still allow only a limited number of users asking questions with hangouts
But then you could have unlimited viewers
I see. Well, maybe they don't know that (I didn't).
Besides, that IS an interesting question :D
I'm a Brie fellow myself
Also it seems you need to use Google+ to use this service
Well, roquefort, myself...
Yes, that's one big disadvantage
4:24 PM
@YvesKlett Kind of, yes.
@YvesKlett I wrote an update for the image uploader.
I think they should integrate it more with Youtube and bill Hangouts as an option for live streaming/collaborating
@YvesKlett With this you can upload directly for chat, which means the url only is copied to clipboard.
@halirutan: Quote: Code or it didn´t happen :-)
@YvesKlett I'm not sure whether @Szabolcs already worked it into the master branch since he has a lot to do currently. Let me check.
ahhhh... alpha testing
4:26 PM
@Kiyura maybe. Probably not in their interest to do so. (People collaborating are not going to tolerate Google ads, and it gives them nothing useful in the way of marketing fodder.)
Google ads only for viewers/collaborators that do not have a Google+ account
@Kiyura anyway, I am not sure if the "seats limited" thing simply for enhanced attention (i.e. marketing)
@YvesKlett, Good point.
@halirutan will try... checking out for now
4:39 PM
@YvesKlett You have to use the ImageUploader.m since I did not update the Latest file.
@YvesKlett please see here:
no.. wait
Nov 27 at 3:13, by halirutan
@All and @Szabolcs I have tweaked the image uploader a bit. It does now show a small icon of our site next to the main-buttons. Additionally, you can now differentiate whether you like to
- mark an uploaded image for QA on the site. Then the url gets the style `![Mathematica graphics](http://i.stack.imgur.com/l2Nnp.png)` which can be directly used in a post
- mark and image for usage in chat, where the pure url only is copied to clipboard
The default button is always "Site" which means you can just hit enter and everything works as expected. Furthermore, I "Queued" the upload buttons so tha
4:59 PM
any one knows how to obtain a list/save to my PC, all the Mathematica twitter tips? I do not have a twitter account and do not want one. I mean the Mathematica tips here twitter.com/MathematicaTip, I wanted to save them as many are useful. Or are they archived there all the time? (sorry, I do not do twitter and no nothing about it really other than it is there)
@NasserM.Abbasi can't you just copy them to a file?
@acl, can't copy, I tried. also I wanted to list them all, I do not know how far in the past they go. too much manual work to copy each by hand. When I point the mouse top copy, it just opens up and does not allow me to copy
it copies fine here. maybe you can scrape the site with whatever language you like for this
@Acl, right. my mistake. I can copy one by one. still too much work but if that is only option,. thought there might be a way to automate it
Is this Mathematica tip correct?
@NasserM.Abbasi isn't that what HoldAll does?
5:11 PM
It says this:

SetAttributes[f, HoldAll]
f[x_] := Hold[x];
f[1 + 2 + 3]
Why we need the SetAttributes[f, HoldAll]?
It works the same by just doing

f[x_] := Hold[x];
f[1 + 2 + 3]
@NasserM.Abbasi without that, 1+2+3gets evaluated before getting to the Hold
I suppose
@NasserM.Abbasi no, did you remember to ClearAll@f first?
I mean, the line SetAttributes[f, HoldAll] is not needed.
@NasserM.Abbasi it's needed
@acl, opps. my mistake :)
forgot to restart the kernel again
@NasserM.Abbasi you just need to ClearAll@f, that's enough
5:13 PM
In Maple, it is much simpler. I always use the command restart;
@NasserM.Abbasi how's that much simpler than Quit?
you don't even need brackets!
In Maple, the command restart can be in the code itself, and not in separate cell.
I mean Quit has to be in a separate cell.
no this works
in a cell
You are right! I swear I tried this before, in old version and it needed to be in separate cell? was this like this all the time?
@NasserM.Abbasi no clue, I used to have it bound to ctrl-Q so I never typed it
5:15 PM
In this case, from now on, I'll just put Quit[] at top of each code I want to run from clean start
I remember trying it before, long time ago, and remember it had to be on its own cell. That is why I did not use it. to lazy to make new cell. thanks this helps now
Easier to type than Clean["Global`*"] also, less typing ;)
@acl, humm... something not right , please see. It is not working as expected
But now when I kill the kernel from the menu, and type this, now it is different
So, Quit; did not do what stopping the kernel did. You see?
I proof it below, it has to be in separate cell ! , look
hm yes that's true
ok, so I was not imaging things. I know I tried this before :)
In Maple, restart can be anywhere in the code, no need for separate cell. much easier to use.
well, if I put
SetAttributes[f, HoldAll]
f[x_] := Hold[x]
f[1 + 2 + 3]
in one cell, it just stops everything at the Quit[]
and so does
SetAttributes[f, HoldAll]
f[x_] := Hold[x]
f[1 + 2 + 3]
SetAttributes[f, HoldAll]
f[x_] := Hold[x]
f[1 + 2 + 3]
@acl. Ok. But this means I can't use it to clear things as I want and to go on to the next code. I have to break things into cells. That is what I meant
@NasserM.Abbasi no, just don't put ;
Don't ask me why
ah no we are idiots
5:27 PM
Sorry, I am do not get it. After Quit I should get Hold[6] not Hold[1+2+3]. You still get Hold[1+2+3] in all cases you show?
When all in one cell.
for this:
SetAttributes[f, HoldAll]
f[x_] := Hold[x]
f[1 + 2 + 3]
I don't
@acl, I do, please see
and I get nothing
OK then I don't know
@NasserM.Abbasi no wait, you're just seeing the previous output
5:30 PM
Actually I get nothing,. that Out[10] was from last time. So the point is, it does not work as when it is on a separate cell :)
Yes. sorry. But the point again, Quit has to be on separate cell. It does not matter if it Quit[] or Quit; or Quit
@NasserM.Abbasi what do you mean? it kills the kernel, what does it do if on a separate cell?
@NasserM.Abbasi I don't follow. It prints nothing because it's killed the kernel, right?
No, I mean I wanted to work like Maple restart, where it clear everything, but goes on to the next line of code with fresh state
not sure I see the difference, for line think cell
well anyway ok then just put it on a separate cell, it's not that big a deal :)
Ok, but the whole point is that it is easier if one did not. That is all. Like Maple restart
Well, restart can be used in Maple scripts, any where. not just in the notebook interface...I never used Mathematica for scripts, do not know how Quit[] will work in middle of code in a script.
@NasserM.Abbasi putting this in a script
and then doing math -script tmp.m prints 1.
but anyway I think there are more major differences between maple and mma than this!
5:46 PM
@acl, I know. But this is important actually. Making a new clean state in Mathematica is not easy. CleanSLate[] and other such tool can be tricky to use. I actually can make V9 kernel crash now when I try to use CleanSlate[] on some contexts I loaded. I reported this to WRI. But I need to make a small test case for them when I have time. But I can reproduce it all the time myself.
@NasserM.Abbasi yes, I agree it would be nice to be able to unload packages etc. but Quit does clean everything; I don't think it's hard to use!
This is useful for unit testing, where one have many tests and want to start each test from the same exact fresh state as when Mathematica started
2 hours later…
8:00 PM
@rcollyer is likely to be forced to fight a very large and very venomous snake very soon... wish him luck!
Q: How to communicate with a StackExchange member about something not specifically related to a question

George WolfeI noticed that Jagra made a comment about a question that is about something I'm interested in too. So I made a comment in the same question area asking him about it. But I assume we don't want to mix personal interest questions into answers. Is there a way to direct a question to a member th...

8:44 PM
@AndyRoss thanks! By the way, is there any use to the dt argument in TemporalData[data, {t0, te, dt}] other than error checking? Any case in which it doesn't provide redundant information?
@Rojo, not unless you allow one or both of t0 and t3 to be Automatic. In that case the endpoints are inferred from dt and the length of the states.
@AndyRoss TemporalData[Range[20], {0, Automatic, 1}] doesn't seem to work, am I doing something wrong?
@Rojo Hmm.. might have made it out the door without that working. It sort of works with dates but should work with number too. I'm actually doing a lot of work on this very thing as we speak. Date handling and specs like this will work much better in 9.0.1.
For example. TemporalData[Range[10], {Automatic, "May 24th 1982", "Day"}] works in 9.0.0.
@AndyRoss Yes it does. Thanks, I get the idea now. Given that you are working on it, what about also allowing a function as a first argument and let TemporalData sample it?
@Rojo, could you send me a notebook with an example of what you mean (andyr@wolfram.com) I welcome the suggestion and concrete examples are very helpful.
8:59 PM
@AndyRoss you menton you are working on date handling -- disclaimer I have not installed 9 yet, watching the discussion before installing -- I've been told that the date and time speeds are now more competitive in 9 compared to earlier versions. So similar fast handling of dates would be something I'd be looking for in TemporalData
which reminds me, in 8 is used to be faster to evaluate tick functions, convert time series to absolute time and then use ListPlot than just using DateListPlot straight up. Improved date and time speeds would have presumably made DateListPlot competitive?
@AndyRoss Sent
@MikeHoneychurch I'll be completely honest. The development of the new date functionality was going on slightly out of sync with TemporalData so it isn't completely rolled in to TemporalData for 9.0.0 and it will probably feel a little hacky until 9.0.1. I'm working to make it fast and hole free for 9.0.1. You should talk to @BrettChampion about DateListPlot.
Maybe @Brett will see this and comment. The slowness of DateListPlot vs ListPlot with custom tick functions was particularly evident when you made plots dynamic. (I'm talking financial series with e.g. 3000 points)
Propaganda for mathematica.stackexchange.com @stackberlin (twitter.com/BMarzewski/status/276397161862811648/photo/1)
9:42 PM
@acl In a notebook, if you have multiple cells you can put Quit in a cell by itself and set this option: SetOptions[$FrontEnd, "ClearEvaluationQueueOnKernelQuit" -> False]
Then if you have a cell above it and below it and select all three and evaluate, the kernel will Quit but the frontend evaluation queue will continue (and restart the kernel for the last cell)
1 hour later…
10:46 PM
@ArnoudBuzing - I can see me using ClearEvaluationQueueOnKernelQuit very soon. Thanks.
@ArnoudBuzing thanks
@NasserM.Abbasi perhaps what Arnoud mentioned is useful for you

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