26 Replies Latest reply on Jul 15, 2016 3:36 PM by Slipp D. Thompson

# Rulers: Y axis. Why does it go bottom up?

Hi... below is a copy of what i posted as a reply/query in another thread. Sorry for repeating but just thought may get more answers here...

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Grateful if someone could explain why:

When turning on rulers, the default for the X axis is the left.

This is as should be and makes sense.

But why is the default for the Y axis the bottom? Shouldn't be the top? After all, other language versions, etc., aside, we're talking lets say :

Left to right, top to bottom flow of content and sight.

So why on earth would the Y axis start from the bottom and go up?

Cheers...

JJ

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PS: Mmmm.... bottom up?

• ###### 2. Re: Rulers: Y axis. Why does it go bottom up?

Larry G. Schneider wrote:

Thanks Larry...

Saw and replied...

JJ

• ###### 3. Re: Rulers: Y axis. Why does it go bottom up?

When you first learned about plotting points on a 2D coordinate system in junior high school, did the y axis positive values increase upward or downward?

JET

• ###### 4. Re: Rulers: Y axis. Why does it go bottom up?

JETalmage wrote:

When you first learned about plotting points on a 2D coordinate system in junior high school, did the y axis positive values increase upward or downward?

JET

Interesting response, I think the question refers to a problem a lot of people have with the technically correct but technically misguided approach to to a way of the practical world. We simply do not construct our graphic material starting from the bottom up and so it is a flaw in the way the thinking is applied in this situation.

It is possible to be completely correct and totally wrong at the same time.

As is the case in the way illustrator's rulers were implemented. probably time to correct it.

• ###### 5. Re: Rulers: Y axis. Why does it go bottom up?

When turning on rulers, the default for the X axis is the left.

This is as should be and makes sense.

By what logic do you assert that it "makes sense" for values of a horizontal axis to increase rightward, yet that values of a vertical axis should increase downward?

The standard coordinate system is completely appropriate for a program ostensibly intended primarily for illustration. Ever seen a set of default axes in a 3D program in which the values increase from the upper left front corner of a coordinate "cube", (i.e.; with height increasing downward) rather than from a central origin? Ever seen a drafting program that doesn't use standard Cartesian coordinates?

Mind you, there would be nothing wrong with Illustrator providing a user-controlled option for when it is being used for page assembly, as do other programs. But given that Illustrator does not provide such an option (for this, like many other things), the Cartesian coordinate system is the correct one for a drawing program.

JET

• ###### 6. Re: Rulers: Y axis. Why does it go bottom up?

In western writing, and book layout, it is expectable to start at the upper left corner and to work right and downwards; and the pages go from left to right; until the book is placed on the shelf.

Most flowers and trees grow upwards from the ground, and unless in water, most of the living always have a perception based on a surface below, and most objects rest upon one.

Illy is well grounded.

• ###### 7. Re: Rulers: Y axis. Why does it go bottom up?

From a program that costs 15% of Illustrator's price:

JET

• ###### 8. Re: Rulers: Y axis. Why does it go bottom up?

JETalmage wrote:

By what logic do you assert that it "makes sense" for values of a horizontal axis to increase rightward, yet that values of a vertical axis should increase downward?

The standard coordinate system is completely appropriate for a program ostensibly intended primarily for illustration. Ever seen a set of default axes in a 3D program in which the values increase from the upper left front corner of a coordinate "cube", (i.e.; with height increasing downward) rather than from a central origin? Ever seen a drafting program that doesn't use standard Cartesian coordinates?

Mind you, there would be nothing wrong with Illustrator providing a user-controlled option for when it is being used for page assembly, as do other programs. But given that Illustrator does not provide such an option (for this, like many other things), the Cartesian coordinate system is the correct one for a drawing program.

JET

Well... i'd say as most Illy users aren't maths students, etc. etc. I'm speaking logically... you have a sheet of paper (that's your Illy page), you tend to draw from the top left downwards to the bottom right...

I know that i work from the top down...(mmm interesting thoughts there if one were to reverse the process ) And, i'm sure most people do the same... kind of weird when you're at the top of a page, trying to position a logo, to see you're -280mm (or whatever). Wouldn't it make more sense to see that you're 17mm down (from the top)?

Simple as that...

At least then, Illy should have an option...

• ###### 9. Re: Rulers: Y axis. Why does it go bottom up?

Jacob Bugge wrote:

In western writing, and book layout, it is expectable to start at the upper left corner and to work right and downwards; and the pages go from left to right; until the book is placed on the shelf.

Most flowers and trees grow upwards from the ground, and unless in water, most of the living always have a perception based on a surface below, and most objects rest upon one.

Illy is well grounded.

Jacob, we're not growing flowers... nor beanstalks We're creating books/pages/whatever. The flow is left to right, top to bottom...

• ###### 10. Re: Rulers: Y axis. Why does it go bottom up?

There you go! Simple as that... an option for the user!

• ###### 11. Re: Rulers: Y axis. Why does it go bottom up?
There you go! Simple as that... an option for the user!

But it would be near the rock-bottom of my priority list. The much-more-important user-defined rulers (also depicted above), on the other hand, would be near the top (along with many other things taken for granted in most drawing programs).

Well... i'd say as most Illy users aren't maths students, etc. etc.

Math students? Are you saying most Illustrator users didn't pass 8th grade?

I'm speaking logically... you have a sheet of paper (that's your Illy page), you tend to draw from the top left downwards to the bottom right...

You're not speaking any more "logically" than anyone else. You're speaking only from the merely habituated preference for a page-building convention. I'm speaking just as "logically" from the much broader convention of illustration.

I know that i work from the top down...

So? When I construct an illustration, height values increase upward. Draw a sailboat. Its mast is 25' tall. Would you measure that from the top?

Simple as that...

Simple as that.

JET

• ###### 12. Re: Rulers: Y axis. Why does it go bottom up?

James,

How many complaints have you heard or read from InDesign, PageMaker, FreeHand, Corel, Word, QuarxXPress, or Photoshop users that the origin is at the top and down is the direction of positive movement? For me, it’s zero. That’s how the vast majority of us think, and it’s not our fault that Illustrator alone does things differently. Nobody (else) cares that up-is-positive is more mathematically correct. If it feels wrong, it is wrong.

The reason Illustrator uses up for positive values and puts zero at the bottom is that that was the basis of Adobe’s PostScript language even before there was an Adobe, and Illustrator’s roots are PostScript. For the first decade or so of its existence, Illustrator’s file format was PostScript. I can remember using free printer utilities to print Illustrator files when Illustrator was not even installed. Nice trick to show people, and faster than launching Illustrator.

As for Wade’s suggestion that ADobe change the behaviour for updates to Illustrator, I agree it would be desirable, but I also think it’s unworkable. Either the format is updated so that the values stored in the file are reversed, or the program leaves the values alone and just flips them as the user works. The latter option has “trouble” written all over it, as miles of code written by long-retired programmers is modified to use the new system. Of course, some routines will be overlooked, producing the buggiest version of Illustrator since the last one. The former would require the program to completely flip all Y-values in the file as it is opened, making opening legacy files slow and probably still introducing errors. Then there are all the plug-ins, actions, and scripts that would need rewriting to be compatible with the new system.

No, the only solution that can work is the one that will eventually fix all of Illustrator’s problems: scrapping the rust bucket completely and starting again. Looking forward to it.

• ###### 13. Re: Rulers: Y axis. Why does it go bottom up?

Scott:

Illustration programs, all.

JET

• ###### 14. Re: Rulers: Y axis. Why does it go bottom up?

See JET...

They all have it wrong!

• ###### 15. Re: Rulers: Y axis. Why does it go bottom up?

From what I can see the arguements for the default location of zero for the Y axis is irrelevent. For the fact that the ruler is user definable. Since the zero can be placed anywhere along the edge it wouldn't be very difficult to create an option for setting the default location along the side of the page. Internally it may have to do some simple math to determine the location should the new page be a different length, but it can easily be done. It really boils down to whether or not Adobe feels it deserves the time to do so.

• ###### 16. Re: Rulers: Y axis. Why does it go bottom up?

In Corel Draw's Options it has an origin option for the ruler. But it would have to be changed if you changed the page size. From what I can tell changing the page size resets the origin back to 0 which is the lower left corner.

• ###### 17. Re: Rulers: Y axis. Why does it go bottom up?

Corel Draw's ruler origin option only moves the origin (as you can do in Illustrator). It does not reverse the Y axis.

Canvas and Xtreme both provide options for reversing the Y axis.

Inkscape also properly has its Y origin at the bottom of the page. Inkscape allows multiple grids per document, including a proper implementation of axonometric grids.

All of these drawing progams provide user-defined ruler scales. Except, of course, Illustrator.

JET

• ###### 18. Re: Rulers: Y axis. Why does it go bottom up?

No one has said that the position of the Y axis should not be optional.

But, with the Y axis at the top and Y values increasing downwards, presuming a reference level at 0, just to mention a few cases:

Swimming duck: quacking beak in the - (range), paddling feet in the + (range);
Rose petals in the -, roots in the +.

Captain: How do you know?
Mastheadman: Jolly Roger at -150 feet.

Animation of funeral: coffin lowered to +6 feet, black hats lifted at -6 feet.

Animation of mourning flag: Y value decreased to hoist the flag to the top, then increased to lower the flag to half-staff/mast.

First floor in the -, basement in the +;
Each step up a building decreases the Y value, as does rising from a chair;
The second floor has a lower Y value than has the first floor;
A painting higher on the wall has a lower Y value.

Transform palette: Subtract from Y value to move up;
Character>Baseline Shift: Increasing shift diminishes Y value;
Font creation: Ascenders in the -, descenders in the -;
Functions and Graph Tool values: Values in the + = Y values in the -;
Nudging: Up Arrow decreases Y values, Down Arrow increases them.

Mariana Trench: down to +36,201 feet;
Dead Sea: down to +1,385 feet;
Denali: up to -20,320 feet;
Chomolungma: up to -29,029 feet.

Resting bat: this is just the way it is.

No one has mentioned the direction of rotation, yet.

• ###### 19. Re: Rulers: Y axis. Why does it go bottom up?

Ever scripted animation in Flash? Flash's stage abides by the silly Y increases downward convention. You know how cumbersome it is to have to continually flop vertical movement values in ActionScript?

Consider: What would be the big deal if raster image programs, page building programs, et al, also abided by the normal Cartesian convention with the origin at the bottom left and vertical values increasing upward? In those environments, you are dealing with nothing but positions on a plain-jane 2D grid (as opposed to transformations, constructions, etc.). What, in Photoshop for example, makes it so important that the "first" pixel is the upper left one? In Photoshop I just as often need to position a guide a given distance from the right edge of the image as from the left. If anything, Photoshop and programs like it should make toggling the direction of both rulers a one-click affair.

I dare say that if, in the mid 80s, the mainstream WYSIWYG software vendors had simply had the good sense to position the horizontal ruler along the bottom edge of the document window instead of along the top edge, fewer users would have a problem with the vertical-begins-at-the-bottom norm, regardless of what kind of program it is. That would appear more intuitive to all, just because the intersection of the two rulers would be at the origin.

JET

• ###### 20. Re: Rulers: Y axis. Why does it go bottom up?

JETalmage wrote:

All of these drawing progams provide user-defined ruler scales. Except, of course, Illustrator.

See, you're on my side! After all...

• ###### 21. Re: Rulers: Y axis. Why does it go bottom up?

Jacob Bugge wrote:

Swimming duck: quacking beak in the - (range), paddling feet in the + (range);
Rose petals in the -, roots in the +.

Captain: How do you know?
Mastheadman: Jolly Roger at -150 feet.

Animation of funeral: coffin lowered to +6 feet, black hats lifted at -6 feet.

No Jacob... while i get your drift, it would be more like...

Masthead at 1ft, deck at 150 ft

Funeral: Coffin lowered 12 feet, hats lifted to 6 feet... Don't forget everything would start at zero...and zero is now at the top. (Or they'd all be minus values...)

However, while i grant the logic of the Y=0 at the bottom, the same confusion applies to a designer...

Top margin= 10 cm. Hell, now, 297mm – 100mm = 197mm... ok so, my top margin is at 197mm.

The difference is actually a much of a muchness... it's just easier to calculate positively than negatively...

Option... set your main plane and put the Y zero there? <shrug> Possibly??

Basically, zero at top or zero at bottom is the same in terms of the paddling duck unless you put the zero at a point along the y axis of the page... other than top or bottom.

Cheers,

JJ

• ###### 22. Re: Rulers: Y axis. Why does it go bottom up?

Jay,

For all the cases in post #18, a reference level at 0 was presumed. That is often convenient when you draw something (maybe to scale) with known dimensions. It may be done by starting at the bottom of the Artboard, maybe at the lower left corner, and moving the artwork later.

But of course we are on your side.

• ###### 23. Re: Rulers: Y axis. Why does it go bottom up?
See, you're on my side! After all...

No, you're all in a tizzy about the direction of the Y axis. User-defined ruler scales is another thing altogether.

JET

• ###### 24. Re: Rulers: Y axis. Why does it go bottom up?

Every where in the world that uses a cartesian coordinate system, has negative values going left and down.

http://en.wikipedia.org/wiki/Cartesian_coordinate_system