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**MathsIsFun****Administrator**- Registered: 2005-01-21
- Posts: 7,608

I am part-way through developing Zoomable Number Line

Comments welcome!

"The physicists defer only to mathematicians, and the mathematicians defer only to God ..." - Leon M. Lederman

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 103,701

Hi MIF;

The zoom works fine but I could not get anything smaller than 1.999 to register on the number line.

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.** **A number by itself is useful, but it is far more useful to know how accurate or certain that number is.**

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**bob bundy****Moderator**- Registered: 2010-06-20
- Posts: 7,548

hi MathsIsFun,

Looks like you've made excellent progress; thank you!

For me the behaviour was a little different. (IE8)

As I zoomed in there was a slight left drift of the numbers, so that, although I had started centred on zero, I became centred on 3.4, then 3.45 and so on.

Just tried it again. Aaarrhh, the light dawns. It depends where I'm pointing on the number line; it zooms out from that point. That's good. Better than in my dream. But maybe it needs an instruction for dumb-brains like me who take ages to work it out.

After 3.450 I had no more resolution to see further digits, although the power of ten count must still have been working .... if I zoomed out, say, another 5 powers of ten, to zoom back took 5 zoom levels again before I was back to where I'd been. This is obviously always going to be a problem as there'll always be a point beyond which you cannot go.

..... Unless, and I'm not sure about this, only every other number is displayed to free up space; then every fifth number ....... Not sure if that would be a solution. Even then a limit point would be reached where the displayed numbers were off the screen and all that would be left would be the line.

So maybe just come up with a "You've reached the limit" notice and then stop zooming. Either way, I don't think it helps with understanding if the digits all start to look like the same number. So perhaps stick at say 6 character width numbers and lock the zoom after that. (But still track left and right with the arrows.)

I can picture learners just liking to operate the zoom and being fascinated by the result. Not realising that they are seeing and learning about the number system in action. Great!

Bob

ps. Shed in bits and moved. Now all I've got to do is put it back together again!!

Children are not defined by school ...........The Fonz

You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei

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**MathsIsFun****Administrator**- Registered: 2005-01-21
- Posts: 7,608

Thanks guys. Yes, after a while there is simply no space to put digits, they overlap badly. Maybe I just let them overlap, and provide a "reset" button.

Bob: all nails removed? how are your arms and hands?

"The physicists defer only to mathematicians, and the mathematicians defer only to God ..." - Leon M. Lederman

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 103,701

Hi MIF;

It would be nice to see more digits, then we could have more discussions about .9999999... = 1.

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.** **A number by itself is useful, but it is far more useful to know how accurate or certain that number is.**

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**bob bundy****Moderator**- Registered: 2010-06-20
- Posts: 7,548

hi MIF and bobbym,

More digits yes, but less numbers perhaps.

If you look at the three screen shots below, taken a few seconds after each other, the numbers are looking a bit crowded, then they spread out and are easily readable, then they get crowded again. Also, in the third shot, there should be another digit showing, but there isn't, so presumably you've got a 'number of characters showing' limit.

How about an algorithm that divides the space available by the number of digits that 'want to be shown according to that power of ten' , to arrive at the optimum amount of numbers so that all their digits will show?

Then, as the powers of ten get more negative, less numbers will show, but to a greater precision. So bobbym gets his wish as the screen fills with more and more 9s (see 4th fiddled screen shot).

I know you enjoy a challenge.

Bob

ps. Hands suffering from too much gripping and twisting. Just been to get some new timber for the base ... old stuff was rotten. Started to construct new base. Chicester would be proud of me.

*Last edited by bob bundy (2011-10-22 00:58:07)*

Children are not defined by school ...........The Fonz

You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei

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**MathsIsFun****Administrator**- Registered: 2005-01-21
- Posts: 7,608

Good thoughts, maybe by taking the log of the scale I can determine the appropriate number of digits and the space they take up. Will work on it.

To get to 0.9999... might be a problem as we run into computer accuracy problems (you know, when 0.345 shows as 0.3449999997) so I may need to have a limit there.

ps. pics of shed before, during (deconstructed), and after would be good!

"The physicists defer only to mathematicians, and the mathematicians defer only to God ..." - Leon M. Lederman

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 103,701

Whoa! I was just being funny with the crack about the .999999999... and needing more digits. I love digits and love seeing them but what was your original idea when you started on this one? Implement that!

A bit of advice: Stop listening to that bobbym fella, check with me first before you do anything he says.

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.** **A number by itself is useful, but it is far more useful to know how accurate or certain that number is.**

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**bob bundy****Moderator**- Registered: 2010-06-20
- Posts: 7,548

But bobbym; I liked the idea. Now let me see ... I should check with you first.

Woooaah. But before doing that, I should check with you first.

But before doing that I should check with you first.

But .....................................................

ERROR! INFINITY LOOP ENCOUNTERED! MAJOR OVERLOAD. ALL FUNCTIONS RESET!

Arrrhhhh. That's better.

Pics of shed before not available due to lack of time machine. Anyone got one I could borrow? If you have, send it to me last week, please.

Other pics possible without time machine. Just one snag. It's still too dark now. Will return to this during the hours of daylight.

Bob

Children are not defined by school ...........The Fonz

You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei

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**MathsIsFun****Administrator**- Registered: 2005-01-21
- Posts: 7,608

bob bundy wrote:

Pics of shed before not available due to lack of time machine.

Just set t = -2 days

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**MathsIsFun****Administrator**- Registered: 2005-01-21
- Posts: 7,608

Cool! Nice looking garden, too.

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**MathsIsFun****Administrator**- Registered: 2005-01-21
- Posts: 7,608

Just an update to let you know I am still working on this as time permits. I am trying to move some of the calculations to Full Precision as the rounding errors look really bad, but that is not as easy as it may sound.

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**bob bundy****Moderator**- Registered: 2010-06-20
- Posts: 7,548

hi MIF,

Well thanks for keeping going. I have every confidence.

Shed update. Had to get the roof on before it rained so Monday was hectic and I was on the roof fixing in wooden slats to hold the felt until it was too dark to see the nails any more. Tuesday, spent the day at my Mother's sorting out her garden. Today finished the slats but rain stopped play. So no final picture yet. Hopefully tomorrow.

Off to see Dave Gorman tomorrow evening. Wow, life is very busy when you're retired!

Really stuck on Juan's integral. I think it's directly integrable for the right choice of 'u' and 'v' in a quotient. But my paper attempts are full of near misses. About to start Version 5.

Bob

You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei

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**MathsIsFun****Administrator**- Registered: 2005-01-21
- Posts: 7,608

Full of rustic charm ... and it looks like it has been there forever!

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**MathsIsFun****Administrator**- Registered: 2005-01-21
- Posts: 7,608

Update: New version. Still a little buggy, but improved: Zoomable Number Line

What do you think? Best to speak up now!

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**bob bundy****Moderator**- Registered: 2010-06-20
- Posts: 7,548

hi MathsIsFun,

That's really brilliant! BIG WOW!

I could certainly go with that version. A few minor things.

As the line zooms there is a moment when only the centre number shows.

Shot below is at the transition from e -7 to e -8. This becomes more likely at higher zoom levels.

It also happens at the transition to 1000000.

What I'd like is that both the old level and the new are visible at the transition, and then the old disappears as the new zooms.

Does that make sense?

Thanks,

Bob

You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei

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**Arthur Bon Zavi****Member**- Registered: 2011-10-30
- Posts: 121

For a reason, I cannot un-zoom it.

In the heart of the night, when it's dark in the lights; I heard the loudest voice - a gun shot on the floor.

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**bob bundy****Moderator**- Registered: 2010-06-20
- Posts: 7,548

Hold the shift key.

Bob

You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei

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**Arthur Bon Zavi****Member**- Registered: 2011-10-30
- Posts: 121

bob bundy wrote:

Hold the shift key.

Bob

Now that works.

In the heart of the night, when it's dark in the lights; I heard the loudest voice - a gun shot on the floor.

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 103,701

Hi MIF;

Is v 0.81 the latest one?

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**

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**MathsIsFun****Administrator**- Registered: 2005-01-21
- Posts: 7,608

Nice. Shiny. Looks like garden shed, but inside it is a fully-fledged state-of-the-art game theater.

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**Sarah Rebekah****Member**- Registered: 2011-09-25
- Posts: 540

thats cool mathisfun

Love is the key to life

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**MathsIsFun****Administrator**- Registered: 2005-01-21
- Posts: 7,608

Thank you ... still working on improvements (when time permits)

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**Sarah Rebekah****Member**- Registered: 2011-09-25
- Posts: 540

u are welcome

Love is the key to life

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**MathsIsFun****Administrator**- Registered: 2005-01-21
- Posts: 7,608

Update of Zoomable Number Line

Can be zoomed up to about 30 digits now, hopefully that is enough

Try "Fullscreen"

Let me know what you think, and any bugs.

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