Solving Boundary Points & Limit of F(x,y) - Physics Forums

[LCKurtz]

As an example, look at:
https://www.physicsforums.com/threads/boundary-points-and-limit-of-f-x-y.772938/

Here, I have inserted parts of my reply at the points in the quote where they are relevant. But when you first open the thread, the first response doesn't make sense unless you "click to expand" so you can see the phrase to which I am replying.

The rest of the parts of the reply do have the whole context showing as they should.

I guess I am asking if you can get rid of the little "click to expand" window and show the whole quoted portion as the default.

 

[Jimmy]

If changing that behaviour isn't an option and you can use custom CSS in the browser you use, a simple work-around is possible.

.quoteExpand
{
  display: none !important;
}

.quote
{
  max-height: none !important;
}

Which browser do you use? Most modern browsers allow use of custom CSS via a file or addon.

Personally, I prefer the truncated quotes but my preference isn't paramount.

 

[Greg Bernhardt]

I guess I am asking if you can get rid of the little "click to expand" window and show the whole quoted portion as the default.

It's definitely a change from the old system. It doesn't appear to be alterable.

 

[phinds]

One thing you could do is to remove from the quote all but the relevant part. I know that's a little more work, but it's a solid workaround (unless the part that is relevant is long)

 

[TumblingDice]

Here, I have inserted parts of my reply at the points in the quote where they are relevant. But when you first open the thread, the first response doesn't make sense unless you "click to expand" so you can see the phrase to which I am replying.

The new system always inserts the entire quote when you click reply, and it presents new challenges and new opportunities at the same time.

I enjoy reading posts where the sender takes time to "break out" the phrases, point-by-point, that they're addressing. Quoting an entire post and typing responses in between the lines isn't as clear to me as when it's nicely laid out - quote : response, quote : response, and so on.

There are two ways I'm aware of that can help.

1) Quote once, insert breaks:
If you like hitting Reply to quote the entire post you're replying to, it only takes a moment to insert additional end/start quote delimiters, and it makes helpful replies so much easier to read.

Just "wrap" your replies inside quote delimiters like this, except use brackets ( [ ] ) instead of the parentheses I'm using for illustration:
(/quote)Here's my reply to your quote, above...(quote)

The first (/quote) will end the quote you're replying to. The ending (quote) will restart the quotation that you're replying to.

2) Quote multiple:
If your device allows you to select text (desktops for sure), you can select the quotes directly from the post you're replying to. The new system will offer popup choices of "Quote" and "Reply". I've been using this feature to select "Quote". The forum allows you to add and queue as many quotes as you like. The edit box where you're replying will display an "Insert Quotes" button at the bottom left corner. You can click this to insert all of the quote pieces you've gathered. This feature is very flexible - you can navigate to a post, select text and choose "Quote" from any message at anytime - the forum will queue it up and provide "Insert Quotes" whenever you like/need.

I hope this makes sense and helps!

 

[jtbell]

If your device allows you to select text (desktops for sure), you can select the quotes directly from the post you're replying to. The new system will offer popup choices of "Quote" and "Reply". I've been using this feature to select "Quote".

The edit box where you're replying will display an "Insert Quotes" button at the bottom left corner. You can click this to insert all of the quote pieces you've gathered.

Note that if you click "Reply" on a post, it quotes that entire post regardless of whatever you've already selected for quoting. You'll have to delete it, if all you want to quote is the stuff you've queued up using the "select and quote" feature. In that case it's better to scroll down to the end of the thread and use the empty edit box there (with the "Insert Quotes" button underneath it).

 

[TumblingDice]

Note that if you click "Reply" on a post, it quotes that entire post regardless of whatever you've already selected for quoting.

Thanks, @jtbell - I didn't think about how the two different quote options would perform if users tried to do too much at once!

So far, I've been using the Reply button when it's easier to quote a short post. On the other hand, I really like the ability to select/highlight specific text in posts, click "Quote" to add to the snippets I plan to respond to, and then use the generic edit box at the bottom of the page to construct my reply post with the aid of "Insert Quotes". Like this:

1) Quote once, insert breaks:
If you like hitting Reply to quote the entire post you're replying to

The "Insert Quotes" is standing by and ready when you create your new post, and always displays what it's prepared to insert before you proceed (for those like me who sometimes work more quickly than the laws of physics allow for...).

 

[Fredrik]

One thing you could do is to remove from the quote all but the relevant part. I know that's a little more work, but it's a solid workaround (unless the part that is relevant is long)
$$\int f(x)\mathrm dx$$ Line 1
Line 2
Line 3

The relevant part is very often too long. Look at how little I had to add to your quote to break it.

Weird. In the preview, two lines of text below the integral was enough. In the actual post, it takes three.

 

[Greg Bernhardt]

I may be able to adjust this but it's also a good opportunity to only be quoting what you are directly responding too.

 

[LCKurtz]

Well that **&^@@! edit/reply/insert quote mess is driving me crazy. I use the +Quote button but when I insert quotes nothing happens. And if I open another window because I want to copy something copy/paste messes up the latex. Then when you post it and it doesn't come out like you expected, good luck trying to include portions of some other quote when you try to edit it to fix it. I HATE it.

 

[Greg Bernhardt]

What browser are you using?

I use the +Quote button but when I insert quotes nothing happens.

Do the quote links change to a grey background when activated? Do you get the "quote added" notification message?

copy/paste messes up the latex

What are you copying and pasting? From editor to editor or from post to editor?

 

[LCKurtz]

What browser are you using?Do the quote links change to a grey background when activated? Do you get the "quote added" notification message?What are you copying and pasting? From editor to editor or from post to editor?

I am using Google Chrome. Just to see what happens, I clicked the +Quote button on my previous post before I hit the reply button for this post and it said "message added to multi-quote". So right now, right here, I am going to click on the Insert Quotes on the next line:

Well that **&^@@! edit/reply/insert quote mess is driving me crazy. I use the +Quote button but when I insert quotes nothing happens. And if I open another window because I want to copy something copy/paste messes up the latex. Then when you post it and it doesn't come out like you expected, good luck trying to include portions of some other quote when you try to edit it to fix it. I HATE it.

OK, that apparently worked. Now I'm going to add a Latex quote:

That would bother me too. In my previous post I showed you

x(t)=x(0)e∫t0p(s) ds​

x(t) = x(0)e^{\int_0^t p(s)~ds}Then I asked you what you get if you set x(t)=x(t+T)x(t)=x(t+T). You haven't done that. Write down exactly what that equation says and see what it says about p(t)p(t). You need to do that before you start considering the periodicity of p(t)p(t). Once you do that you can try to prove the iff thing about pp being periodic.

OK, that hosed the LaTeX. It also duplicated stuff like p(t)p(t).

I have tried various things, some of which work and some don't. I never know what's going to happen.

 

[Greg Bernhardt]

testing latex in a quote

That would bother me too. In my previous post I showed you
##x(t)=x(0)e∫t0p(s) ds##
##x(t) = x(0)e^{\int_0^t p(s)~ds}##Then I asked you what you get if you set ##x(t)=x(t+T)x(t)=x(t+T)##. You haven't done that. Write down exactly what that equation says and see what it says about ##p(t)p(t)##. You need to do that before you start considering the periodicity of ##p(t)p(t)##. Once you do that you can try to prove the iff thing about pp being periodic.

 

[Greg Bernhardt]

How are you adding latex to a quote? I appears to have worked for me. I don't see the latex tags in the quote you tried.

 

[LCKurtz]

How are you adding latex to a quote? I appears to have worked for me. I don't see the latex tags in the quote you tried.

You don't get the same ##c## on each interval. You could say there exists ##c_j \in [x_{j-1},x_j]## such that$$
f'(c_j)=\frac{f(x_j)-f(x_{j-1})}{\Delta x_j}$$

The rest of your argument has gone off the tracks. The next thing you should write down is the sum you are trying to work with:$$
L(P,f') = \sum_{j=1}^n m_j\Delta x_j$$Now think about how ##f'(c_j)## compares with ##m_j##.

OK. On the above I added the message with the multi-quote and inserted the quote in this message. Let's see how it looks.

[Edit] Looks ok that time. I dunno. Bedtime for now.

 

[LCKurtz]

OK, continuing on. Here's a specific problem I'm having. Let's say I decide a post I just posted needs clarification by adding an equation I have posted before in LaTeX. So I open the edit window on my post. Now there is no "insert quotes" button. How do I get a latex expression copied into my editing reply?

 

[Greg Bernhardt]

So I open the edit window on my post. Now there is no "insert quotes" button.

The edit window doesn't have multiquote functionality. You'll have to create the quotes manually. To get the latex code, right click on the equation, select "show math as" and select text command.

 

[LCKurtz]

The edit window doesn't have multiquote functionality. You'll have to create the quotes manually. To get the latex code, right click on the equation, select "show math as" and select text command.

OK, I hadn't noticed that was still available and I see it works fine for a single equation. However, suppose I want to include a full paragraph, text and latex, from some previous post as clarification in my edit, perhaps something I overlooked to include in my original post. How do I do it?

 

[Greg Bernhardt]

How do I do it?

How did you do it in the old site?

 

[Fredrik]

OK, I hadn't noticed that was still available and I see it works fine for a single equation. However, suppose I want to include a full paragraph, text and latex, from some previous post as clarification in my edit, perhaps something I overlooked to include in my original post. How do I do it?

Hit reply first. Copy the quote. Then edit your post and paste the quote into it. Then remove everything you don't need from that quote.

 

[LCKurtz]

Hit reply first. Copy the quote. Then edit your post and paste the quote into it. Then remove everything you don't need from that quote.

Thanks Fredrik, that seems to work. But I just did it on this post:

https://www.physicsforums.com/threa...ann-integrable-functions.773441/#post-4869097

If I bring up that post the "click to expand" is now missing and you can't see the equation after the "Now," which I added.

 

[Fredrik]

Thanks Fredrik, that seems to work. But I just did it on this post:

https://www.physicsforums.com/threa...ann-integrable-functions.773441/#post-4869097

If I bring up that post the "click to expand" is now missing and you can't see the equation after the "Now," which I added.

I'm not sure I understand what you did, or what your post looked like before you edited it. Are you saying that you decided that you had quoted too small a part of his post, and wanted to include more of it? And also that you tried to use my suggestion to include more? This is how I would have done it: 1. Click the Reply button next to his post. 2. Copy all the text from the editor window. 3. Click the Edit button next to your post. 4. Select the original quote tags and everything between them. 5. Paste the quote. (Since the original quote is selected, it's replaced by the new version). 6. Remove everything between the quote tags that you still don't want to include. 7. Either save the changes, or click "more options" to get a preview before you save the changes.

Alternatively, 4. Find the place where you want to insert more stuff and click it to place the cursor there. 5. Paste the quote. 6. Remove everything from (and including) the new opening quote tag to the start of the section that you want to include. 7. Remove everything from the end of the section that you want to include to (and including) the the new closing quote tag.

 

[Borek]

@Greg Bernhardt

https://xenforo.com/community/threa...ble-the-click-to-expand-quotes-feature.55243/

 

[Greg Bernhardt]

@Greg Bernhardt

https://xenforo.com/community/threa...ble-the-click-to-expand-quotes-feature.55243/

We'll put it to a vote next week.

 

[LCKurtz]

I'm not sure I understand what you did, or what your post looked like before you edited it. Are you saying that you decided that you had quoted too small a part of his post, and wanted to include more of it?

Yes. That's exactly what I wanted to do.

And also that you tried to use my suggestion to include more? This is how I would have done it: 1. Click the Reply button next to his post. 2. Copy all the text from the editor window. 3. Click the Edit button next to your post. 4. Select the original quote tags and everything between them. 5. Paste the quote. (Since the original quote is selected, it's replaced by the new version). 6. Remove everything between the quote tags that you still don't want to include. 7. Either save the changes, or click "more options" to get a preview before you save the changes.

I did what I believe was equivalent to that. I clicked reply. At that point I removed the parts of his quote I didn't want to add, just leaving the paragraph I wanted between the quotes. Then I edited my post, removed the old quote and I copied (ctrl-c) what I wanted. The final result has
the modified quote between his original quote tags.

What is weird is that if I edit it now it looks just as it should in the edit window. The lines that don't show in the quote window are there in the post and it's just that you can't expand the window to see them.

 

[Fredrik]

OK, that's pretty weird.

Okay...

There exists a ##c_j\in [x_{j-1},x_j]## such that $$f'(c_j)=\frac{f(x_j)-f(x_{j-1})}{\Delta x_j}$$ Now $$L(P,f')=\sum_{j=1}^n m_j\Delta x_j$$ And $$m_j=inf\{ f'(c_j):c_j\in [x_{j-1},x_j]\}$$ $$\Leftrightarrow m_j=\frac{inf\{ f(x_j)-f(x_{j-1})\} }{\Delta x_j}$$ $$\Leftrightarrow L(P,f')=\sum_{j=1}^n \frac{inf\{ f(x_j)-f(x_{j-1})\} }{\Delta x_j}\Delta x_j=\sum_{j=1}^n inf\{ f(x_j)-f(x_{j-1})\} $$ $$\Leftrightarrow L(P,f')=\sum_{j=1}^n m_j\Delta x_j\leq f(b)-f(a)$$

?

Edit: I'm getting the same result as you. It doesn't matter if I first quote a small segment and then edit in the rest, or if I quote that entire post in a new post. The part after the "Now," simply isn't displayed. This has to be a bug.

I don't see anything in that post that looks suspicious.

@Greg: If you click Edit on this post (my post), you will see that I'm quoting more than just the stuff that you see in the quote box.

 

[Borek]

Another test post.

Okay...

There exists a ##c_j\in [x_{j-1},x_j]## such that $$f'(c_j)=\frac{f(x_j)-f(x_{j-1})}{\Delta x_j}$$ Now, $$L(P,f')=\sum_{j=1}^n m_j\Delta x_j$$ And $$m_j=inf\{ f'(c_j):c_j\in [x_{j-1},x_j]\}$$ $$\Leftrightarrow m_j=\frac{inf\{ f(x_j)-f(x_{j-1})\} }{\Delta x_j}$$ $$\Leftrightarrow L(P,f')=\sum_{j=1}^n \frac{inf\{ f(x_j)-f(x_{j-1})\} }{\Delta x_j}\Delta x_j=\sum_{j=1}^n inf\{ f(x_j)-f(x_{j-1})\} $$ $$\Leftrightarrow L(P,f')=\sum_{j=1}^n m_j\Delta x_j\leq f(b)-f(a)$$

?

 

[Borek]

Okay...

There exists a ##c_j\in [x_{j-1},x_j]## such that $$f'(c_j)=\frac{f(x_j)-f(x_{j-1})}{\Delta x_j}$$ Now, $$L(P,f')=\sum_{j=1}^n m_j\Delta x_j$$ And $$m_j=inf\{ f'(c_j):c_j\in [x_{j-1},x_j]\}$$ $$\Leftrightarrow m_j=\frac{inf\{ f(x_j)-f(x_{j-1})\} }{\Delta x_j}$$ $$\Leftrightarrow L(P,f')=\sum_{j=1}^n \frac{inf\{ f(x_j)-f(x_{j-1})\} }{\Delta x_j}\Delta x_j=\sum_{j=1}^n inf\{ f(x_j)-f(x_{j-1})\} $$ $$\Leftrightarrow L(P,f')=\sum_{j=1}^n m_j\Delta x_j\leq f(b)-f(a)$$

?

 

[Borek]

Definitely a bug.

 

[Borek]

What if I use text/itex tags?

Okay...

There exists a ##c_j\in [x_{j-1},x_j]## such that $$f'(c_j)=\frac{f(x_j)-f(x_{j-1})}{\Delta x_j}$$ Now $$L(P,f')=\sum_{j=1}^n m_j\Delta x_j$$ And $$m_j=inf\{ f'(c_j):c_j\in [x_{j-1},x_j]\}$$ $$\Leftrightarrow m_j=\frac{inf\{ f(x_j)-f(x_{j-1})\} }{\Delta x_j}$$ $$\Leftrightarrow L(P,f')=\sum_{j=1}^n \frac{inf\{ f(x_j)-f(x_{j-1})\} }{\Delta x_j}\Delta x_j=\sum_{j=1}^n inf\{ f(x_j)-f(x_{j-1})\} $$ $$\Leftrightarrow L(P,f')=\sum_{j=1}^n m_j\Delta x_j\leq f(b)-f(a)$$

?

Okay...

There exists a ##c_j\in [x_{j-1},x_j]## such that $$f'(c_j)=\frac{f(x_j)-f(x_{j-1})}{\Delta x_j}$$ Now $$L(P,f')=\sum_{j=1}^n m_j\Delta x_j$$ And $$m_j=inf\{ f'(c_j):c_j\in [x_{j-1},x_j]\}$$ $$\Leftrightarrow m_j=\frac{inf\{ f(x_j)-f(x_{j-1})\} }{\Delta x_j}$$ $$\Leftrightarrow L(P,f')=\sum_{j=1}^n \frac{inf\{ f(x_j)-f(x_{j-1})\} }{\Delta x_j}\Delta x_j=\sum_{j=1}^n inf\{ f(x_j)-f(x_{j-1})\} $$ $$\Leftrightarrow L(P,f')=\sum_{j=1}^n m_j\Delta x_j\leq f(b)-f(a)$$

?

Okay...

There exists a ##c_j\in [x_{j-1},x_j]## such that $$f'(c_j)=\frac{f(x_j)-f(x_{j-1})}{\Delta x_j}$$ Now $$L(P,f')=\sum_{j=1}^n m_j\Delta x_j$$ And $$m_j=inf\{ f'(c_j):c_j\in [x_{j-1},x_j]\}$$ $$\Leftrightarrow m_j=\frac{inf\{ f(x_j)-f(x_{j-1})\} }{\Delta x_j}$$ $$\Leftrightarrow L(P,f')=\sum_{j=1}^n \frac{inf\{ f(x_j)-f(x_{j-1})\} }{\Delta x_j}\Delta x_j=\sum_{j=1}^n inf\{ f(x_j)-f(x_{j-1})\} $$ $$\Leftrightarrow L(P,f')=\sum_{j=1}^n m_j\Delta x_j\leq f(b)-f(a)$$

?Same bug apparently.

 

[Greg Bernhardt]

For some reason the comma after now was breaking it. I took it our and it worked.

edit, hmmm if I refresh it breaks again

 

[Greg Bernhardt]

Look at boreks last post. I added the same tex 3 times and it works. Something is conflicting before.

 

[LCKurtz]

OK Greg, since I started this thread and demonstrated this anomaly (bug?) do I get rewarded by Grandfathering my Gold membership without paying up again when my original one expires?

 

[Greg Bernhardt]

OK Greg, since I started this thread and demonstrated this anomaly (bug?) do I get rewarded by Grandfathering my Gold membership without paying up again when my original one expires?

That's only if you fix the problem :D

 

[LCKurtz]

That's above my pay grade.