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Old Nov 8, 2012, 01:02 PM   #226
isephmusic
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Quote:
Originally Posted by steve dave View Post
What if we like it and find it useful. Then do we have your permission to buy it?
it goes out on a debate because yes they are trying to cater to the casuals and the people who don't care about resolution, it saves them money. but for the rest of us who need a mini with good horsepower and HD PDF read-ability it sucks for us because we constantly have to let them catchup to standards that should really be the low standards. my transformer infinity has a micro sd card, 1900x1200 resolution, micro hdmi out, weighs less than ipad4 and a keyboard that not only adds 6 hours MORE battery life it includes a full size USB. i had the choice to switch over to it, but why cant apple just do it ? why do i have to always wait on them to release what should of been the first.

do whatever you want. my post is i really dont want americas consumers to be conditioned into waiting and low expectations. no one wins that way dude
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Old Nov 8, 2012, 01:26 PM   #227
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I had another go today thinking I'd been too hasty returning my launch day Mini. I use Google Currents, Pulse and Flipboard a lot and the font is just too small in the Mini. Some apps you can adjust the size but not in others. The font is simply too small.

I'm not a big fan of the lower resolution screen but the real deal breaker for me remains the size of the fonts. So back it goes again. And I love the size and the weight. It's just that screen simply isn't usable for me.
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Old Nov 8, 2012, 09:02 PM   #228
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Quote:
Originally Posted by rkuo View Post
This is a rather silly game of semantics and not really correct.
It's not semantic at all, apart from the apparent lack of understanding of what causality means.
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You are assuming PPI is held constant when the screen size changes, so therefore it doesn't change.
No, I am explicitly not making that assumption. I am saying that ppi is wholly independent of screen size.

Quote:
PPI does not have to change, but that doesn't mean it won't. In fact, due to Apple's desire for integer doubling of resolution or nothing at all, it's far more likely that PPI would change with screen size.
That's all true.

The point was and is a very simple one: there is no causal relationship between display size and pixel density, and pixel density is therefore not dependent either on screen size or resolution.

----------

Quote:
Originally Posted by emaja View Post
Really, how hard is it to understand "pixels per inch?"
It shouldn't be hard at all. But there's a staggering lack of basic mathematical and scientific literacy on these forums.

"Pixels per inch" is a very real, physical parameter defined and caused by the size of an individual pixel. Nothing more, nothing less.

0.00464" = 216ppi = 0.118mm dot pitch. Doesn't matter if it's a 0.5" display or a 40" display. Doesn't matter if it's a display with 8 pixels or 8 million. Doesn't matter if you build it to 1280x800 or 2560x1600 resolution.
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Old Nov 8, 2012, 11:46 PM   #229
rkuo
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Quote:
Originally Posted by lianlua View Post
It's not semantic at all, apart from the apparent lack of understanding of what causality means.

No, I am explicitly not making that assumption. I am saying that ppi is wholly independent of screen size.


That's all true.

The point was and is a very simple one: there is no causal relationship between display size and pixel density, and pixel density is therefore not dependent either on screen size or resolution.
No and no. It's not independent, and, yes, you are making that assumption even though you don't understand it yet. One can make an explicit decision to hold PPI constant while varying the screen dimensions, which is what you are referring to. That is not the same thing as independence.

The equation is simply pixels / inches = PPI. How much more obvious can it be that they are related? Pixels per INCH. If one varies inches in this equation, PPI changes. Therefore, a dependent variable. Furthermore, a display cannot be fully specified with a PPI measurement. It MUST have screen dimensions and it MUST have a resolution. Only then does PPI exist.

What you continue to harp on is the equivalent of claiming that V * A = W and that Watts aren't related to Volts. It just ain't so. They are, by definition, related measurements.

Causation is also irrelevant. What "causes" these measurements are human factor decisions. Units have no "causation", but they can be related. They are measurements.
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Old Nov 9, 2012, 02:03 PM   #230
lianlua
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Quote:
Originally Posted by rkuo View Post
It's not independent, and, yes, you are making that assumption even though you don't understand it yet.
Have you seriously read nothing in this discussion? Pixel density is not an abstract, mathematical fiction.

It is a restatement of pixel size. It has absolutely nothing to do with what you do to other variables in an equation that allows you to solve for other display attributes.

You and spungoflex are the ones making an assumption to hold values constant because you're trying to solve an equation rather than look at what's right in front of you.
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One can make an explicit decision to hold PPI constant while varying the screen dimensions, which is what you are referring to. That is not the same thing as independence.
No. In order for your argument to work that display size changes ppi, you have to hold a third value constant (resolution). I am saying that you cannot hold any of those values constant against each other.

Resolution and pixel density are independent of display size. You can pick any two values and solve for the third, but that does not create a causal relationship in the real, physical world that we live in.
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The equation is simply pixels / inches = PPI. How much more obvious can it be that they are related?
And the fuel economy measure is miles / gallons. But neither the number of miles driven nor the number of gallons in the tank causes fuel economy to change.
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Pixels per INCH. If one varies inches in this equation, PPI changes. Therefore, a dependent variable.
No. Display size is the dependent variable in the equation, because it cannot be adjusted in the real world by itself. You can't magically resize a display to any arbitrary size you want outside of theory land.

Here's how you build an LCD: you take pixels, which have a measurable physical size, which you can state in ppi, dot pitch, or outright inches or millimeters. Then you put a number of them together in a grid. Those two values, pixel size and resolution, both of which you can independently select, determine the third, display size. You can't do it the other way around. You can't say that you need a screen of exactly 6.632" in diagonal size and exactly 1000x1000 resolution and therefore the pixels are automatically .00632", because the size of the pixels is not dependent on the size of the display. They are the size that they are, no matter what you do to them.
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It MUST have screen dimensions and it MUST have a resolution. Only then does PPI exist.
No. The value of 'ppi' exists wholly independently of the display. All you need to calculate ppi is one pixel.

Say a pixel falls off the production line and you want to find out the density of the display it was going into. Take that one pixel and put it under a microscope. Measure it. Let's say it 0.05" across. You're done! You know it's for a 20ppi display. You don't need to know what the final size or resolution is. It's irrelevant. You don't even need 20 pixels. You don't need an inch of pixels. You just need that one, solitary pixel to calculate ppi.
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What you continue to harp on is the equivalent of claiming that V * A = W and that Watts aren't related to Volts.
No. What I'm saying is that a change in voltage is not a change in wattage unless you are specifically stacking the deck by holding amperage constant.

If I give you the two figures of 100W and 1000W in isolation, with no other information, you cannot tell me that the higher wattage necessarily is associated with a higher voltage. They're independent properties. One has no bearing on the other in isolation. That they're related in an equation does not make them caused by each other in the real world.

The same is true of miles per gallon. If I tell you that one vehicle has a 1 gallon fuel tank, and another vehicle has a five gallon fuel tank, you can't tell me that the 1-gallon vehicle necessarily gets higher mpg. You can't tell me from the fuel capacity either the consumption rate or the range.
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Causation is also irrelevant.
Causation is the entire point of this discussion. Causation is what makes an independent variable independent (although your lack of understanding this does explain why you misused "dependent variable" above). The comment was that smaller screens necessarily have higher pixel density. This is not true. There is no causal link between the size of a display and the size of its pixels.
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Units have no "causation", but they can be related. They are measurements.
Measurements must have causation or they cannot be defined. They are frequently related in mathematical equations that allow you to calculate variable C by knowing parameters A and B. That most definitely does not mean that changing A causes C to change as well. You need to know what all three are doing, and when you move from math to reality, you also need to know which two of the three you can actually physically manipulate.

Last edited by stridemat; Nov 13, 2012 at 01:15 PM. Reason: Cleanup
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Old Nov 9, 2012, 04:48 PM   #231
rkuo
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Quote:
Originally Posted by lianlua View Post
Have you seriously read nothing in this discussion? Pixel density is not an abstract, mathematical fiction.
Look, this is pointless because you refuse to acknowledge that you are arbitrarily holding PPI constant to make this silly argument.

PPI is a DERIVED measurement. You cannot measure PPI directly. You only calculate it by counting pixels and measuring inches. PPI by definition is related to screen dimensions and pixel count per the very simple equation. If you remove inches from the equation, you don't have an equation any more.

This can be demonstrated via a simple thought exercise.

Given a PPI measurement of 96 PPI, what does a display look like?
Given a screen of 16 inches wide by 9 inches tall, with 1920x1080 pixels, what does a display look like?

The first does not specify the display, the second does. That is a demonstration of primary measurements vs derived measurements.

None of whatever else you said makes any sense. I apologize if this is blunt but you really need think more about the difference between claiming two measurements aren't related and holding one constant in an equation.

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Old Nov 9, 2012, 07:53 PM   #232
lianlua
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Quote:
Originally Posted by rkuo View Post
you refuse to acknowledge that you are arbitrarily holding PPI constant
Because I am doing no such thing.
Quote:
PPI is a DERIVED measurement. You cannot measure PPI directly.
You most certainly can, as has been illustrated for you.
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PPI by definition is related to screen dimensions and pixel count
No, it isn't. It is by definition related to how many pixels fit into a linear inch. It is irrelevant whether you actually build a display with those pixels. Ppi does not change based on either resolution or size. All three are linked in a finished display, but it is the display length that changes based on the selected values of resolution and pixel density.
Quote:
per the very simple equation.
You don't need that equation at all!
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If you remove inches from the equation
No one is removing inches from anything. You're simply misunderstanding what the "inch" in ppi refers to.
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The first does not specify the display, the second does.
No, it doesn't. The first statement specifies pixel density. It doesn't fully describe a display because it's only providing one of the 3 values you need. The second statement also does not specify the display. It gives you only 2 of the 3 values you need. You can now compute the third. But it doesn't matter which two you provide. You can always calculate the third value.

You don't need a finished display to calculate pixel density. You need one damn pixel. That's it. A display built with 0.05" pixels will always be 20ppi, whether it's in a 1024x768 display or whether it's in a display measuring 100" by 50". It's 20ppi even if the finished display has neither 20 pixels in nor measures an inch long.
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That is a demonstration of primary measurements vs derived measurements.
It's a demonstration only of you continuing not to get it.
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I apologize if this is blunt but you really need think more about the difference between claiming two measurements aren't related and holding one constant in an equation.
You really need to think about the difference between two variables being related in a three-variable equation and one value causing a change in the other. It does not. Changing one of three values in an equation means that at least one of the other values must also change, but it doesn't specify which value changes, nor does the change in one cause a change in the other. You are the one arbitrarily holding a third value constant.

If I tell you that e=mc^2, you can't say that a change in c necessarily causes e to change. It doesn't. A change in c can result in a change in e, m, or both.

So it is here. If you tell me that one display is 7" and the other is 15", that means nothing with regard to pixel density. The only way you can claim that ppi is forced to change is by holding resolution constant. Even if we do hold resolution constant for you, resolution divided by physical display dimension produces an approximation of pixel density, not an exact measure.

The exact measure of ppi is 1/(width of one pixel).

Last edited by stridemat; Nov 13, 2012 at 01:20 PM. Reason: Cleanup
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Old Nov 11, 2012, 07:45 PM   #233
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The only measurement you need to know to measure PPI is the distance between electrodes. There is no need for a screen size or resolution.

PPI is determined by how close together manufacturers can print electrodes onto the glass substrate surface and still maintain acceptable yield rates and brightness/constrast ratios.

To claim that PPI is determined causally by the size of the screen is utter nonsense.
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Old Nov 11, 2012, 07:51 PM   #234
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A manufacturer does not build a screen by choosing a particular screen size and then fitting a certain number of pixels into that rectangle. If they went that route, the pixel size would be a result of the choices that were made for screen size and resolution. However, the pixel is the foundation on which the entire screen is built. The available pixel sizes are fixed via technical capabilities and production before they are ever assigned to a particular screen size. This is what lianlua is saying - and I quote:

Quote:
Here's how you build an LCD: you take pixels, which have a measurable physical size, which you can state in ppi, dot pitch, or outright inches or millimeters. Then you put a number of them together in a grid. Those two values, pixel size and resolution, both of which you can independently select, determine the third, display size. You can't do it the other way around. You can't say that you need a screen of exactly 6.632" in diagonal size and exactly 1000x1000 resolution and therefore the pixels are automatically .00632", because the size of the pixels is not dependent on the size of the display. They are the size that they are, no matter what you do to them.
Sure, the pixel-per-inch value may be derived from a particular screen size and resolution, but it's not how the screen is designed in the first place, and a given pixel may be translated to any panel size (within technological constraints).

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Old Nov 12, 2012, 07:13 PM   #235
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Electrode distance determines PPI. How far apart you want to cut the glass pieces determines screen size. Resolution is the determined by the above 2 combinations. End of story.
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Old Nov 12, 2012, 08:21 PM   #236
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I held off stating anything about the display until I was actually able to see an iPad Mini. This week I was at a Best Buy and I made it a point to go check one out. I thought the display was great. Looking at the icons, they were just as crisp as the ones on my iPad 3. I couldn't tell a difference. I played around on Safari and could barely notice a difference. I also played around on iBooks there I could notice a difference, but if I am busy reading the content, not studying the font, it wouldn't matter to me.

As long as iPads in general remain a quality product and I continue to use my iPad for the same uses that I am now, I am 99% certain that when it's time to upgrade my iPad 3, I will switch over to a mini. Although by then, they may have the retina display anyhow.
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Old Nov 13, 2012, 12:43 PM   #237
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MOD NOTE

Please ensure that the bickering / arguing behaviour is curtailed. We have spent a considerable amount of time going through this thread. Please keep it civil and inline with the Rules for Appropriate Debate.
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