The best thing about Flot, I reckon, is that it gives you a nice-looking graph pretty much by default.

I think the trickiest thing I did on my monitoring thing was the day/weekend shading, and maybe the smoothing, although that was more a case of me being slow to understand how Savitzky-Golay works (it's actually pretty simple).

Well I seemed to have solved the major issue of being able to tell what the date/time is by using a proper time format in the database rather than doing conversions. All new entries are added with a unix time stamp.

Heh yeah using a numeric timestamp makes things much easier, for one thing because that's what the Flot-time thing expects, and for another it makes it easier to do comparisons.

Well that's definitely much better


Now to make it look nicer. Thanks for suggesting Flot!

One thing I did to make mine look slightly nicer is to trim the start to where the time is a whole number if minutes/hours – that way you get nice round "16:00" time labels, rather than "16:42" and such.

Good idea, that would make things look a bit better.

Looking much better

http://www.antthomas.co.uk/temperature/

Only real issue is that the database is on my home server so it's a bit slow, especially on the larger time periods.

Do you have indexes on the columns you are joining / sorting on in your database tables?

Yeah, all have an id which is auto incremented.

I did think of just getting odds or evens to half the data.

What are you monitoring?

I figured you'd have some sort of fancy AJAXy thing to update in real time.

Are you sorting the data (ORDER BY) on the primary key? If you're using another column you'll be wanting to add an index to it. MySQL will really thank you if you do.

You might get better performance by storing the date and time as MySQL's native datetime column and using the MySQL UNIX_TIMESTAMP() function to convert it to a Unix timestamp for Flot, just don't order on the function results as MySQL isn't very good at that, i.e.

SELECT UNIX_TIMESTAMP(datetime_column) as unix_timestamp FROM table ORDER BY datetime_column DESC.

 

This is the query I'm using...

$query = "SELECT * FROM (SELECT * FROM outside ORDER BY id DESC LIMIT $limit) AS foo ORDER BY id ASC";

	    $result = mysql_query($query);
	    while($row = mysql_fetch_assoc($result))
	    {
	    $dataset1[] = array(($row['unixtime'] * 1000 ),$row['temperature']);
            }

 

Hahaha I really can't use the code tags :'D

That's better....  I think.

The number of users active on my Guild Wars 2 Bounty Tracker app. The numbers have been a bit... wrong the past few days as I've been experimenting with different sync methods and some people apparently haven't refreshed their browser since Saturday :-/

There's no point in updating it in real-time, really – it'd just mean a huge amount of data that wouldn't really provide any more useful information than the current polling 2-minute interval.

Some thoughts:

1) drop shadow on a graph looks like wank and makes it harder to read. I keep thinking my eyes are failing to focus properly. WHERE DID YOU LEARN HOW TO GRAPH, POWERPOINT LOL?

2) increase the number of grid lines, 5 degrees apart seems a bit much.

c) I am picky

iv) that seems like an awfully big temperature variance, for optimum results your weed farm should remain between about 21 C and 26 C.

a) I agree. It's the default setting.

ii) I am going to increase the grid lines.

γ) There's nothing wrong with being picky

4) The sun reaches my balcony at about 5pm

That looks fine. How are you limiting the results when selecting the different scales, are you just assuming there will always be a maximum number of readings a day and adjusting the limit?

Yeah maximum plus 20 more to give few extra at the start.

1hour - 80
2 hours - 140
6 hours - 380
12 hours - 740
1 day - 1440
1.5 days - 2180
2 days - 2900
7 days - 10100

It defaults to 2900

To me graphs are about being able to see trends and anything less than 1 day doesn't really tell you much so I might get rid of them when I have a decent amount of data.

• Good

1. I'm glad