incorrect result with Math.wrap()

Posted on Wed 22nd, January 2014

• #1

Kim

The result of Math.wrap(4,3) is 0.A. I assume this is a floating point bug of some sort?
• #2

Gordon

Heh, yes. Sorry - I was actually trying to fix this last night.

The artithmetic is absolutely fine - it's a bug in the float to string code. I was actually trying to fix this just yesterday, but I've added a bug for it to track it now: https://github.com/espruino/Espruino/issues/190
• #3

Kim

Thanks. I'll delve into the code myself some day so that I can help out in fixing these issues, but some day so far seems to have been a moving target ;).

As for the fix, I assume you'll just need to use some threshold when converting floating points as you will never get a perfect mapping. I have some code that I wrote a while back for a similar issue, but I'll have to dig it up though ...
• #4

Gordon

Hi Kim,

Yes, I thought I'd used a threshold - but it turns out to be slightly more tricky than that (or I'm doing something very wrong!).
• #5

Kim

Seems to be fixe with 1.46 :). Do you collect any release notes on new versions?
• #6

Gordon

Great! Info here:

http://www.espruino.com/ChangeLog

Yes, that is one of the things I fixed. It's not perfect IMO but it's an awful lot better :)

Post a reply
- Bold
- Italics
- Link
- Image
- List
- Quote
- code
- Preview
Formatting Help

Don't worry about formatting, just type in the text and we'll take care of making sense of it. We will auto-convert links, and if you put asterisks around words we will make them bold.

Tips:

Create headers by underlining text with ==== or ----

To *italicise* text put one asterisk each side of the word

To **bold** text put two asterisks each side of the word

Embed images by entering:
![](https://www.google.co.uk/images/srpr/logo4w.png)
That's the hard one: exclamation, square brackets and then the URL to the image in brackets.

* Create lists by starting lines with asterisks

1. Create numbered lists by starting lines with a number and a dot

> Quote text by starting lines with >

Mention another user by @username

For syntax highlighting, surround the code block with three backticks:

```
Your code goes here
```
Just like Github, a blank line must precede a code block.

If you upload more than 5 files we will display all attachments as thumbnails.

For a full reference visit the Markdown syntax.