# Are there any systems where charts start positive on the left and decrease to the right? **URL:** \ **Category:** Factual Questions\ **Created:** [June 5, 2013, 5:05am UTC](https://boards.straightdope.com/t/are-there-any-systems-where-charts-start-positive-on-the-left-and-decrease-to-the-right/660184 "2013-06-05T05:05:52Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Wolverine](https://avatars.discourse-cdn.com/v4/letter/w/ba9def/32.png) [@Wolverine](https://boards.straightdope.com/u/Wolverine)\ **Post date:** [June 5, 2013, 5:05am UTC](https://boards.straightdope.com/t/are-there-any-systems-where-charts-start-positive-on-the-left-and-decrease-to-the-right/660184/1 "2013-06-05T05:05:52Z")
I’ve been drawing a lot of charts recently in both my calculus and statistics classes. All of my charts put the lowest value of the x-axis to the left and increasing x values to the right. Negative values are placed left of zero and positive values are placed right of zero. Are there any systems that put the highest horizontal value of the chart to the left and decreasing values of x to the right? ---
**Author:** ![DataX](https://avatars.discourse-cdn.com/v4/letter/d/e99b99/32.png) [@DataX](https://boards.straightdope.com/u/DataX)\ **Post date:** [June 5, 2013, 5:22am UTC](https://boards.straightdope.com/t/are-there-any-systems-where-charts-start-positive-on-the-left-and-decrease-to-the-right/660184/2 "2013-06-05T05:22:03Z")
Grrr - I know I have seen and used this, but am having trouble remembering where - sometimes I do it myself in excel by checking option to put axis in reverse order. In general - if memory serves it is most useful when you want to think of something going down - even when the numbers go up - an example would be a hypnogram of sleep stages. > **[Hypnogram](https://en.wikipedia.org/wiki/Hypnogram)** > > A hypnogram is a form of polysomnography; it is a graph that represents the stages of sleep as a function of time. It was developed as an easy way to present the recordings of the brain wave activity from an electroencephalogram (EEG) during a period of sleep. It allows the different stages of sleep: rapid eye movement sleep (REM) and non-rapid eye movement sleep (NREM) to be identified during the sleep cycle. NREM sleep can be further classified into NREM stage 1, 2 and 3. The previously consid... Unfortunately this doesn’t meet your requirement - as it is on the y axis instead of x, but principle is the same. I’ll try and remember something that traditionally uses this on x axis, but I’m sure someone else will find one first… ---
**Author:** ![wevets](https://avatars.discourse-cdn.com/v4/letter/w/e9a140/32.png) [@wevets](https://boards.straightdope.com/u/wevets)\ **Post date:** [June 5, 2013, 5:29am UTC](https://boards.straightdope.com/t/are-there-any-systems-where-charts-start-positive-on-the-left-and-decrease-to-the-right/660184/3 "2013-06-05T05:29:34Z")
Depth charts in oceanography frequently have the y-axis running from zero and increasing as it approaches the x-axis ([like this one](http://www.coexploration.org/bbsr/classroombats/html/chlordp.html),) just like the one mentioned by **DataX**. I can’t think of anything where this is commonly done on the x-axis. There’s probably something esoteric out there, though. ---
**Author:** ![Wolverine](https://avatars.discourse-cdn.com/v4/letter/w/ba9def/32.png) [@Wolverine](https://boards.straightdope.com/u/Wolverine)\ **Post date:** [June 5, 2013, 5:35am UTC](https://boards.straightdope.com/t/are-there-any-systems-where-charts-start-positive-on-the-left-and-decrease-to-the-right/660184/4 "2013-06-05T05:35:11Z")
I was particularly thinking it might happen in other cultures like those with right-to-left reading systems, but as far as I know Arabic and Japanese make charts similar to Western practices. I did a quick search, but everything was about writing numbers in other numerical systems, not charts. ---
**Author:** ![cmyk](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cmyk/32/3353_2.png) [@cmyk](https://boards.straightdope.com/u/cmyk)\ **Post date:** [June 5, 2013, 7:10am UTC](https://boards.straightdope.com/t/are-there-any-systems-where-charts-start-positive-on-the-left-and-decrease-to-the-right/660184/5 "2013-06-05T07:10:11Z")
It’s not cartesian, but by far, the wavelengths of the EM spectrum are typically depicted and graphed as the longer wavelengths increasing in size from right to left. ---
**Author:** ![cmyk](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cmyk/32/3353_2.png) [@cmyk](https://boards.straightdope.com/u/cmyk)\ **Post date:** [June 5, 2013, 7:25am UTC](https://boards.straightdope.com/t/are-there-any-systems-where-charts-start-positive-on-the-left-and-decrease-to-the-right/660184/6 "2013-06-05T07:25:03Z")
Other than that, any coordinate system or graphed data seems to be merely an arbitrary convention at this point, probably due the the prevalence of western left-to-right languages during scientific revolution since the 1600s; having a natural tendency to read progressive information from left-to-right. I think a deeper question, is is there anything that demands an intrinsically “chiral” representation from right to left? ---
**Author:** ![Isilder](https://avatars.discourse-cdn.com/v4/letter/i/cc9497/32.png) [@Isilder](https://boards.straightdope.com/u/Isilder)\ **Post date:** [June 5, 2013, 7:25am UTC](https://boards.straightdope.com/t/are-there-any-systems-where-charts-start-positive-on-the-left-and-decrease-to-the-right/660184/7 "2013-06-05T07:25:37Z")
> [@Wolverine](#): > > I’ve been drawing a lot of charts recently in both my calculus and statistics classes. All of my charts put the lowest value of the x-axis to the left and increasing x values to the right. Negative values are placed left of zero and positive values are placed right of zero. > > Are there any systems that put the highest horizontal value of the chart to the left and decreasing values of x to the right? Rocket launches countdown ? Oh but thats negative. “T -20 and counting”. Years ? 2000 BC , 1000 BC .. BEFORE CHRIST. there’s no minus sign… its not stated to be a negative number on the graph/chart. ---
**Author:** ![Khristy](https://avatars.discourse-cdn.com/v4/letter/k/57b2e6/32.png) [@Khristy](https://boards.straightdope.com/u/Khristy)\ **Post date:** [June 5, 2013, 8:06am UTC](https://boards.straightdope.com/t/are-there-any-systems-where-charts-start-positive-on-the-left-and-decrease-to-the-right/660184/8 "2013-06-05T08:06:14Z")
A chart showing the value of Facebook stock, perhaps? ---
**Author:** ![naita](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/naita/32/5862_2.png) [@naita](https://boards.straightdope.com/u/naita)\ **Post date:** [June 5, 2013, 8:20am UTC](https://boards.straightdope.com/t/are-there-any-systems-where-charts-start-positive-on-the-left-and-decrease-to-the-right/660184/9 "2013-06-05T08:20:35Z")
Hertzsprung-Russel diagrams, originally using spectral classes along the x-axis, have temperature decreasing towards the right. ---
**Author:** ![AaronX](https://avatars.discourse-cdn.com/v4/letter/a/7bcc69/32.png) [@AaronX](https://boards.straightdope.com/u/AaronX)\ **Post date:** [June 5, 2013, 8:49am UTC](https://boards.straightdope.com/t/are-there-any-systems-where-charts-start-positive-on-the-left-and-decrease-to-the-right/660184/10 "2013-06-05T08:49:17Z")
Shifts in NMR spectroscopy are shown with 0 on the right and increasing to the left. ---
**Author:** ![johnpost](https://avatars.discourse-cdn.com/v4/letter/j/f17d59/32.png) [@johnpost](https://boards.straightdope.com/u/johnpost)\ **Post date:** [June 5, 2013, 1:54pm UTC](https://boards.straightdope.com/t/are-there-any-systems-where-charts-start-positive-on-the-left-and-decrease-to-the-right/660184/11 "2013-06-05T13:54:43Z")
if the slide or transparency is flipped around then it is. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [June 5, 2013, 3:13pm UTC](https://boards.straightdope.com/t/are-there-any-systems-where-charts-start-positive-on-the-left-and-decrease-to-the-right/660184/12 "2013-06-05T15:13:26Z")
I’ve seen it in magazine articles, where the text flows around the chart and the layout designer decided it looked better with the chart to the right of the text. It can also be used when you’re plotting two different quantities on different sides of a central axis, [like this XKCD](http://xkcd.com/1127/). ---
**Author:** ![OldGuy](https://avatars.discourse-cdn.com/v4/letter/o/3bc359/32.png) [@OldGuy](https://boards.straightdope.com/u/OldGuy)\ **Post date:** [June 5, 2013, 4:54pm UTC](https://boards.straightdope.com/t/are-there-any-systems-where-charts-start-positive-on-the-left-and-decrease-to-the-right/660184/13 "2013-06-05T16:54:40Z")
There are some examples where the x axis concept might be measured by a variable which moves in the opposite direction where this is used. For example, in economics a commonly used utility function for consumption is C[sup]a[/sup]/a with a \< 1. For this function the aversion to risk is 1-a so you might see a graph of something plotted against a starting at 1 where it intersects the Y axis and decreasing. ---
**Author:** ![Napier](https://avatars.discourse-cdn.com/v4/letter/n/ce73a5/32.png) [@Napier](https://boards.straightdope.com/u/Napier)\ **Post date:** [June 6, 2013, 10:59pm UTC](https://boards.straightdope.com/t/are-there-any-systems-where-charts-start-positive-on-the-left-and-decrease-to-the-right/660184/14 "2013-06-06T22:59:12Z")
Wave number in infrared spectroscopy. ---
**Author:** ![excavating\_for\_a\_mind](https://avatars.discourse-cdn.com/v4/letter/e/e8c25b/32.png) [@excavating\_for\_a\_mind](https://boards.straightdope.com/u/excavating_for_a_mind)\ **Post date:** [June 7, 2013, 12:25am UTC](https://boards.straightdope.com/t/are-there-any-systems-where-charts-start-positive-on-the-left-and-decrease-to-the-right/660184/15 "2013-06-07T00:25:42Z")
> [@Wolverine](#): > > Are there any systems that put the highest horizontal value of the chart to the left and decreasing values of x to the right? That would just be sinister. excavating (for a mind) ---
**Author:** ![thelurkinghorror](https://avatars.discourse-cdn.com/v4/letter/t/7c8e57/32.png) [@thelurkinghorror](https://boards.straightdope.com/u/thelurkinghorror)\ **Post date:** [June 7, 2013, 12:53am UTC](https://boards.straightdope.com/t/are-there-any-systems-where-charts-start-positive-on-the-left-and-decrease-to-the-right/660184/16 "2013-06-07T00:53:39Z")
> [@cmyk](#): > > It’s not cartesian, but by far, the wavelengths of the EM spectrum are typically depicted and graphed as the longer wavelengths increasing in size from right to left. Yes, although this is likely done because it plots the inverse: _frequency_ of waves increases to the right. With the visible spectrum (a small range within the EM spectrum), the wavelength is considered the main description of light and thus more relevant (by some), thus wavelength increases to the right (VIBGYOR from left to right or ROYGBIV from right to left; 380 - 780 nm or so). Not the x axis, but in electroencephalography research, there are two main camps depending on research interest. Many people nowadays put time in ms on X and amplitude (typically microvolts) on the Y axis. Another group of people prefer to flip the whole thing along the horizontal axis, so that EEG amplitude increases as you go down. That means that a “positive peak” of brain activity is at the bottom. No, I don’t know why. ---
**Author:** ![cmyk](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cmyk/32/3353_2.png) [@cmyk](https://boards.straightdope.com/u/cmyk)\ **Post date:** [June 8, 2013, 11:56pm UTC](https://boards.straightdope.com/t/are-there-any-systems-where-charts-start-positive-on-the-left-and-decrease-to-the-right/660184/17 "2013-06-08T23:56:31Z")
> [@thelurkinghorror](#): > > Yes, although this is likely done because it plots the inverse: _frequency_ of waves increases to the right. With the visible spectrum (a small range within the EM spectrum), the wavelength is considered the main description of light and thus more relevant (by some), thus wavelength increases to the right (VIBGYOR from left to right or ROYGBIV from right to left; 380 - 780 nm or so). Good point. Although, as with any graph, it simply depends on how you look at it (i.e. wavelength; frequency; energy). Despite any misconceptions, I’ve always imagined it reading from right-to-left due to the planck length theoretically being factor being a limitation as the wavelength shortens inversely proportional to its frequency (and a longest wavelength, I believe more vaguely considered up to size of the universe itself, yet not sure if this potential limitation has a basis as sound as the planck length?). I can’t help but see some origin somewhere way off to the right of gamma rays in these ubiquitous charts. YMMV Of course the radiation/energies in relation to its frequency would be proportionally inverse to that, and if graphed, from left-to-right. 😉 As I said, I can’t really think of any graph that has some intrinsic property that makes sense to map it in on a particular cardinal axis or direction. It’s all convention/arbitrary, most likely due to the ubiquitous prominence of Cartesian coordinates throughout science, mathematics and geometry. ---
**Author:** ![cmyk](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cmyk/32/3353_2.png) [@cmyk](https://boards.straightdope.com/u/cmyk)\ **Post date:** [June 9, 2013, 12:03am UTC](https://boards.straightdope.com/t/are-there-any-systems-where-charts-start-positive-on-the-left-and-decrease-to-the-right/660184/18 "2013-06-09T00:03:57Z")
Of course, if you ignore the real numbers, imaginary or complex numbers are graphed right-to-left. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [June 9, 2013, 12:29am UTC](https://boards.straightdope.com/t/are-there-any-systems-where-charts-start-positive-on-the-left-and-decrease-to-the-right/660184/19 "2013-06-09T00:29:25Z")
> [@](#): > > Quoth **cmyk** : > > (and a longest wavelength, I believe more vaguely considered up to size of the universe itself, yet not sure if this potential limitation has a basis as sound as the planck length?). The long-wavelength limitation has a basis far more sound than the short-wavelength limitation. We know that there is a limit to the size of the observable Universe, and that one can’t meaningfully have a wave longer than that size. We don’t know that the Planck length has any particular significance, though: That’s just a plausible rough guess. And even if the Planck length does have real significance, it might be significance of a sort which does not preclude shorter waves. ---
**Author:** ![cmyk](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cmyk/32/3353_2.png) [@cmyk](https://boards.straightdope.com/u/cmyk)\ **Post date:** [June 9, 2013, 12:35am UTC](https://boards.straightdope.com/t/are-there-any-systems-where-charts-start-positive-on-the-left-and-decrease-to-the-right/660184/20 "2013-06-09T00:35:46Z")
> [@Chronos](#): > > The long-wavelength limitation has a basis far more sound than the short-wavelength limitation. We know that there is a limit to the size of the observable Universe, and that one can’t meaningfully have a wave longer than that size. We don’t know that the Planck length has any particular significance, though: That’s just a plausible rough guess. And even if the Planck length does have real significance, it might be significance of a sort which does not preclude shorter waves. Interesting, Thanks **Chronos.** We also figure the universe beyond the observable is far, far larger. And while I understand anything beyond this point is inaccessible to us forever (including any light since the big bang), due to the expansion of space/inflationary period, how does this impose a limitation on the wavelength of a photon being no longer than the observable dimensions? [Next page](https://boards.straightdope.com/t/are-there-any-systems-where-charts-start-positive-on-the-left-and-decrease-to-the-right/660184.md?page=2)