Fitbit (and other optical/LED-based devices’) HR Accuracy

Reposted here from Facebook for reference:

Not sure how many out there are Fitbiters but I believe this applies equally to all wrist/LED-based HR monitors (e.g. Apple Watch, Garmin devices, and other trackers). My own anecdotal testing corroborates this study as does DC Rainmaker’s review of the Garmin 235, i.e. they are good at low intensity but get less accurate as intensity increases.

NB: The study referenced was commissioned by the plaintiffs in a class action lawsuit agains Fitbit, so bias is a strong possibility. The descriptive language could be more neutral but it’s hard to deny the data.

NYT Article
Just How Accurate Are Fitbits? The Jury Is Out

Validation of the Fitbit® SurgeTM and Charge HRTM Fitness Trackers

DC Rainmaker Review of Garmin 235 (HR Accuracy)
Garmin Forerunner 230 & 235 In-Depth Review

Setting a UIButton’s Image in Swift

yourButton.ImageView?.image is a READ-ONLY property!!!
yourButton.ImageView?.image is a READ-ONLY property!!!
yourButton.ImageView?.image is a READ-ONLY property!!!
yourButton.ImageView?.image is a READ-ONLY property!!!
yourButton.ImageView?.image is a READ-ONLY property!!!

yourButton.setImage(UIImage(named: “name_of_image”), forState: UIControlState.Normal)

OpenMP Clang in Xcode

I’ve been playing around with prime numbers recently, which (naturally?) extended into an investigation into parallel programming. I installed the latest version of GCC 5 (v5.3.0 at the time of writing) using these instructions and got OpenMP running (support is built-in). I’m fine with using Terminal but I thought it would be interesting to try this in Xcode.

I installed the OpenMP C/C++ language extensions for Clang using homebrew with instructions from here. Unfortunately, I received the following error:

can't exec '/usr/local/bin/clang++-omp' (No such file or directory)

It turns out those instructions were missing a symlink that needs to be created. It’s as follows:

sudo ln -s /usr/local/bin/clang-omp++ /usr/local/bin/clang++-omp

Thanks to Stack Overflow for the “full” instructions. I can now build and run C++ parallelized code directly inside Xcode. I am finding a performance difference running the same code via the Terminal vs inside Xcode (which is slower). Hmm…

NBA Playoff Bracket 2016

I just realized I forgot to post this. It’s not pretty, in that it doesn’t look nice. It was done through OfficePoolManager. I couldn’t find an online tool that allowed you to pick your teams like they have for March Madness and the NHL playoffs.NBA Playoff Bracket 2016

UITextView Padding

If you align a UITextView with another element, particularly a UILabel, using Auto Layout you will notice the text in the UITextView is slightly indented. The UITextView is actually implemented inside an NSTextContainer which has some padding around it. To remove this (left/right) padding, set the following property of the UITextView to zero:

textView.textContainer.lineFragmentPadding = 0


Malware on the (Chinese) App Store

Here is a comment I wrote regarding the recent discover of apps containing malware on the Chinese App Store.

1. This is the first such event in over 7 years (and Billions of downloads) of the App Store’s existence, unlike the almost daily occurrence on other platforms.

2. You correctly didn’t echo the false and sensationalized comments of an “attack” on the App Store, as there was no attack.

3. This was limited to Chinese developers circumventing several Apple safeguards. Not that Apple shouldn’t be able to (ultimately) catch this, and they did, but developers should know better than to turn off Gatekeeper, download Xcode from unauthorized servers, and then not check it’s authenticity. Any of these measures would have prevented such an occurrence.

4. Not making excuses but given the security measures within the iOS environment, these apps did virtually no damage. Here’s a quote: Palo Alto Networks Director of Threat Intelligence Ryan Olson claims the impact was likely negligible, with no reports data theft, or “other harm.”