Version 2.0.0 Available now!

I recently (February 27, 2015) released an update for both iSlideRule and iSlideRule HD. I've moved them closer to being the "same" app in that both now support all the same scales, and both have identical features, other than the number of scales per stator/slide that are presented.

iSlideRule still has 4 scales per stator, while iSlideRule HD presents 5 scales.

I have fixed the "nudge" issue which plagued earlier releases. Touching the top or bottom stator on the left side of the rule should move the slide to the left, and a touch on the right moves the slide right 1 point. Similarly, touching the slide on the left or right side will move the stators left or right one point.

Updated documentation, support for iOS 8 and the iPhone 6 and 6 Plus devices, along with full retina graphics throughout, and newly generated scales for all scales, and additional gauge marks were all provided in this update.

That said, some issues have been discovered. The descriptions and equations displayed for the inverse log (LL/0, LL/1, LL/2, and LL/3) scales has the equations listed in reverse order. The equation given for LL/0 is for LL/3 and vice versa, as are the equations given for LL/2 and LL/1. I'll fix this in a patch update in a couple of weeks. I also saw that while my HTML documentation renders and displays fine on the desktop, the dimensional analysis table has some square block characters where a script-L and some other Greek characters are supposed to be. Again, I'll fix this in the upcoming 2.0.1 patch update.

If anyone finds anything else in the 2.0.0 release that is questionable, please let me know via email! Thanks!

1.2.1 and 1.0.1 are available, and 1.2.2 and 1.0.2 are in review

You have probably noticed; I released an update a few weeks ago for both the iSlideRule, and iSlideRule HD apps. These updates didn't add too much, but in were done to enable the multi-tasking features that were provided back in iOS 4, and fix a minor issue that resulted in the secondary and tertiary scale selections not being selected in the proper order on the scales.

So, today, I released two new updates to the App Store. This update adds iOS 6 support, and iPhone 5 support. I've also added a feature that was asked for some time back; the ability to view (rapidly) both ends of the slide rule without moving the cursor (something that was asked for clear back in the initial 1.0 release!)

Sorry it took me so long on this one. Anyway, in this update (1.2.2 for iSlideRule, and 1.0.2 for iSlideRule HD), touching the center slide with two fingers and panning left or right will rapidly move the view to the left or right index. Releasing the touch lets the view "snap back" to the cursor position. Hopefully, this will provide the feature that folks have been wanting.

I also added a two-finger swipe up/down gesture on the cursor to temporarily switch to the previous or next color in the settings order.

The big update is to the iSlideRule HD app, where I've added several new scales, used for "dimensional analysis" (think "Analon" slide rule and you've got it).
The new scales are ONLY available on the primary rule set, and ONLY available in specific positions on the top, center, and bottom slides; the primary reason for this is that the label descriptions for these scales are not the usual type of description; but instead show the dimensional relationships between the various properties provided on each scale. I highly recommend finding a copy of the Analon manual online and reading it while "playing" with these scales.

In other news; with the latest update in tools from Apple, it is nearly impossible to support devices that only use iOS 4.2.1 and earlier. Apple has removed support for devices that can only run iOS earlier than 4.3 from their development tools. So; with that in mind, the latest versions of iSlideRule and iSlideRule HD will only run on iOS 4.3 and later. So; what does this mean? It means the iPhone 3 and earlier versions, and iPod Touch 2nd generation and earlier are not supported in this latest update. I really hope that most folks are running newer harder by now…

iSlideRule HD running on an iPad Retina-display model, with a VGA dock connector to a big-screen projector is just plain cool!

Also, as my weblogging tool is losing the ability for folks to comment via my weblog, I suggest just emailing me your comments directly… I can always post general comments received by email to my log.

Thanks! - Steve

1.1.0 is out, and 1.1.1 update is in the works

Version 1.1.0 finally made it onto the App store. So, what am I to do now? Update the app yet again I guess.

I've already started (and nearly finished) a minor update, 1.1.1, that adds 2 additional scales (KZ and T2, fundamental scales folded at 360). Additionally, I've went in and added gauge marks on some of the scales for some key values...

On the CI, KZ, T2, C, and D scales, I've added gauge marks at 12 and 144.

On the C and D scales, I've added C and C' gauge marks at √(4/π) and √(40/π).

On the C and D scales, I've also added a p gauge mark at π/180, a p' mark at (180*60)/π, a p'' mark at (180*60*60)/π, and a p0 mark at 180/π, and a mark on the C scale only, at (200*100*100)/π.

Additionally, on the A and B scales, I've added gauge marks M at 100/π, and π/4 marks.

I also updated the documentation with the new scales, and added a "clear" cursor option (I don't really care for it too much, but there it is...), and I "tweaked" the timing on some of the touch-associated motions (like the delay for single-tap vs double-tap recognition to avoid moving things by 1 pixel when a slide scale change is really wanted...)

I should be sending this update out fairly soon, after I get done running my checks on it to ensure everything works.


1.1.0 Released (for Apple Review)

Yesterday, July 31st, I released version 1.1.0 of the iSlideRule app to Apple for review. Hopefully, if all goes well in review, the update will be available within the next week.

It's been quite a while since I had done an update (November of 2008 was the last update). This update includes a lot of changes from the previous version, mostly based on feedback from customers.

I've provided a means via the Settings application to specify the order in which to place scales. This was a prime issue in earlier versions and one I had to address.

I've also added what I think is a unique, educational aspect to the app; it can display a numeric value on the cursor that represents the value on each visible scale under the hairline. Of course, there is an option in Settings to turn this off.

Another new feature is double-tapping the scales. There are now three sets of four scales for each of the rules, and slider. This gives an effective 36-scale slide rule. Scales are selectable from the Settings application. Double-tapping each rule or slider changes the scales to the next set.

Single-tapping the rules or slider moves the opposite 1 pixel for fine-tuning of position. And this brings up something that people need to realize about slide rules, and slide rules on digital devices...

The scales in iSlideRule are 1964 pixels wide (32 pixels of "white" space on either end). So, the "C" scale for example has 1900 pixels between 1 and 10. This means, from a calculation standpoint, that there are only 1900 unique numbers available between 1 and 10. On a "real" slide rule, the user would "guess" or estimate position and value visually; mid-way between two "ticks" would be visually interpreted for value.

In iSlideRule, since there are limited locations for "ticks", if they were drawn in a distinct line, some scales would have ticks that would be four, then five, then four, pixels apart, and would have an uneven distribution.

When generating scales for iSlideRule, I took an approach wherein I generated the scales at 4x the size I needed, then reduced them to the final size with anti-aliasing. So; I get scales wth ticks that appear evenly spaced, however they are a bit "fuzzy" or blurred. It's still up to the user to visually interpret the position of the hairline over the values to come up with the answer. This was my solution to how to represent an "analog" device such as a sliderule, on a digital platform; while providing as close to a real, useful tool, as possible.

By the way, another new feature on iSlideRule is the "flip view", accessible from the main, portrait orientation by pressing the little "info" ( i ) button in the lower right of the display. This will bring up a simple quick guide that covers configuration and settings, gestures and usages, and short details on all sixty of the available scales (yes, I also update the scale selection from 40 to 60 in this release).

I hope everyone enjoys the update as much as I enjoyed spending time creating it!


Upcoming Features in future versions

There are many features that I plan on updating and/or adding to iSlideRule over the next weeks and months.

Primary among the features list that I'm planning and working on is moving the configuration and settings into the application so that scales and color can be updated while the application is running. In addition, I'll be adding a feature that will permit positioning of the scales on their individual slides. Settings will be accessible from "portrait" viewing mode via a control present on screen to flip the whole view over.

Another feature that will be added will be a flip-side view of each slide and rule with additional scales. Unlike a normal slide rule however, that has two sides, each slide will have three sides (think triangular engineering and/or drafting rulers), with 4 scales each (12 scales possible on each bar), and each one can be "flipped" independently of the others. I've got an approach that allows me to use up and down swiping on the rules to perform the flip, and flip to the appropriate view.

Lastly, of some use to those that have a hard time reading the numbers and ticks on the rules, I'll be adding a selectable feature to have the current viewable scales values shown on screen (in portrait mode, they'll be shown below the bars and labeled. In landscape mode, while I haven't completely settled on the approach, they'll probably be displayed, after a slight delay, on top of the cursor, in a semi-transparent way, and disappear while moving the cursor.