OK, enough just playing around with ChatGPT; let’s see if it can write some code:

Continue reading “ChatGPT Writes Decent Code For Binary to Decimal Conversion”

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# Tag: Kotlin

## ChatGPT Writes Decent Code For Binary to Decimal Conversion

## Jetpack Compose Byte Converter App: 2022 Version

## Anomalies In IntelliJ Kotlin Floating-Point Literal Inspection

## A Simple Binary To Decimal Converter App In Jetpack Compose

## Direct Generation of Double Rounding Error Conversions in Kotlin

## Double Rounding Errors in Decimal to Double to Float Conversions

Binary Numbers, Binary Code, and Binary Logic

OK, enough just playing around with ChatGPT; let’s see if it can write some code:

Continue reading “ChatGPT Writes Decent Code For Binary to Decimal Conversion”

I wrote a simple byte to decimal converter app less than two months into starting to learn Jetpack Compose. Now that I have more experience with Compose — in developing a real app and by participating on the #compose channel on Slack (login required) — I wanted to update this demo app to reflect my current understanding of best practices.

Continue reading “Jetpack Compose Byte Converter App: 2022 Version”

IntelliJ IDEA has a code inspection for Kotlin that will warn you if a decimal floating-point literal exceeds the precision of its type (*Float* or *Double*). It will suggest an equivalent literal (one that maps to the same binary floating-point number) that has fewer digits, or has the same number of digits but is closer to the floating-point number.

For *Double*s for example, every literal over 17-digits should be flagged, since it never takes more than 17 digits to specify any double-precision binary floating-point value. Literals with 16 or 17 digits should be flagged if there is a replacement that is shorter or closer. And no literal with 15 digits or fewer should ever be flagged, since doubles have of 15-digits of precision.

But IntelliJ doesn’t always adhere to that, like when it suggests an 18-digit replacement for a 13-digit literal!

Continue reading “Anomalies In IntelliJ Kotlin Floating-Point Literal Inspection”

I’ve been learning Jetpack Compose and Kotlin (and Android for that matter) so I decided to create a simple binary conversion app to demonstrate how easy it is to create (at least basic) UI in Compose.

(This app has been updated; see Jetpack Compose Byte Converter App: 2022 Version.)

Continue reading “A Simple Binary To Decimal Converter App In Jetpack Compose”

For my recent search for short examples of double rounding errors in decimal to double to float conversions I wrote a Kotlin program to generate and test random decimal strings. While this was sufficient to find examples, I realized I could do a more direct search by generating only decimal strings with the underlying double rounding error bit patterns. I’ll show you the Java BigDecimal based Kotlin program I wrote for this purpose.

Continue reading “Direct Generation of Double Rounding Error Conversions in Kotlin”

In my previous exploration of double rounding errors in decimal to float conversions I showed two decimal numbers that experienced a double rounding error when converted to float (single-precision) through an intermediate double (double-precision). I generated the examples indirectly by setting bit combinations that forced the error, using their corresponding exact decimal representations. As a result, the decimal numbers were long (55 digits each). Mark Dickinson derived a much shorter 17 digit example, but I hadn’t contemplated how to generate even shorter numbers — or whether they existed at all — until Per Vognsen wrote me recently to ask.

The easiest way for me to approach Per’s question was to search for examples, rather than try to find a way to construct them. As such, I wrote a simple Kotlin^{1} program to generate decimal strings and check them. I tested all float-range (including subnormal) decimal numbers of 9 digits or fewer, and tens of billions of random 10 to 17 digit float-range (normal only) numbers. I found example 7 to 17 digit numbers that, when converted to float through a double, suffer a double rounding error.

Continue reading “Double Rounding Errors in Decimal to Double to Float Conversions”