Comments on: How to plot dates in Google Charts API http://www.tomfotherby.com/blog/index.php/2009/01/how-to-plot-dates-in-google-charts-api/ My little place in cyberspace Thu, 22 Jul 2010 05:57:40 +0000 hourly 1 http://wordpress.org/?v=3.0 By: Hansinator http://www.tomfotherby.com/blog/index.php/2009/01/how-to-plot-dates-in-google-charts-api/comment-page-1/#comment-7762 Hansinator Fri, 30 Oct 2009 23:32:22 +0000 http://www.tomfotherby.com/blog/?p=742#comment-7762 Hi. I am running a personal training blog/diary and your WP plugin was very valuable and interesting. I am tracking a graph over "records", that is, the time i use on different routes. Unfortunately, the plugin stalls when i enter too many dates and the site wont even show up. Any smart solutions? Hi. I am running a personal training blog/diary and your WP plugin was very valuable and interesting. I am tracking a graph over “records”, that is, the time i use on different routes. Unfortunately, the plugin stalls when i enter too many dates and the site wont even show up. Any smart solutions?

]]> By: Greg Fitzgerald http://www.tomfotherby.com/blog/index.php/2009/01/how-to-plot-dates-in-google-charts-api/comment-page-1/#comment-6821 Greg Fitzgerald Sun, 17 May 2009 21:59:42 +0000 http://www.tomfotherby.com/blog/?p=742#comment-6821 I have another solution for charting dates. The problem with caluclating differences from the first date, is it works fine when the data points are evenly spaced time intervals and tehre is no gaps in the data, otherwise the data points do not line up with the labels. This solution may not work under all scenarios. Instead, know the range of dates you are plotting, and put in a fixed number of labels. and base the data point value on the nuber of pixels per label. e.g. I'm charting 24 hours from midnight through to midnight, therefore i have 25 labels, i.e. 00:00 to 24:00, showing hourly intervals. Each graph will always have 25 labels and 24 spaces between them as google evenly spaces the lables along the axis. I make the axis 1000 pixels long, therefore each space btween the labels is 1000/24 pixels long. The first data point 00:00 is plotted as zero pixels across, the last data point 24:00 is = (1000/24) * 24 pixels across. general formula is for each data point extract the number of hours and minutes from each timevalue associated with that data point and worked out the axis value with (hrs * 1000/24) + (mins/60 * 1000/24). I have another solution for charting dates. The problem with caluclating differences from the first date, is it works fine when the data points are evenly spaced time intervals and tehre is no gaps in the data, otherwise the data points do not line up with the labels.

This solution may not work under all scenarios.
Instead, know the range of dates you are plotting, and put in a fixed number of labels. and base the data point value on the nuber of pixels per label. e.g.
I’m charting 24 hours from midnight through to midnight, therefore i have 25 labels, i.e. 00:00 to 24:00, showing hourly intervals. Each graph will always have 25 labels and 24 spaces between them as google evenly spaces the lables along the axis.
I make the axis 1000 pixels long, therefore each space btween the labels is 1000/24 pixels long.
The first data point 00:00 is plotted as zero pixels across, the last data point 24:00 is = (1000/24) * 24 pixels across.
general formula is for each data point extract the number of hours and minutes from each timevalue associated with that data point and worked out the axis value with
(hrs * 1000/24) + (mins/60 * 1000/24).

]]> By: Danysworld http://www.tomfotherby.com/blog/index.php/2009/01/how-to-plot-dates-in-google-charts-api/comment-page-1/#comment-6646 Danysworld Thu, 30 Apr 2009 10:03:34 +0000 http://www.tomfotherby.com/blog/?p=742#comment-6646 Hi! I saw your plugin but I can't get out of it :( It does not work :( How can I have (like you) a list with "weight(kgs)". In that list, I only have "views" and it does something weird :( If it is possible, I can modify the code but I need some help to do it in the right place :) Hope to hear from you soon because I would so much use you plugin in my blog :) Take Care Hi!
I saw your plugin but I can’t get out of it :( It does not work :( How can I have (like you) a list with “weight(kgs)”. In that list, I only have “views” and it does something weird :( If it is possible, I can modify the code but I need some help to do it in the right place :)

Hope to hear from you soon because I would so much use you plugin in my blog :)
Take Care

]]> By: KarlP http://www.tomfotherby.com/blog/index.php/2009/01/how-to-plot-dates-in-google-charts-api/comment-page-1/#comment-5399 KarlP Fri, 13 Mar 2009 19:31:26 +0000 http://www.tomfotherby.com/blog/?p=742#comment-5399 Having some similar issues with this myself, and while you've got the values plotted along the x-axis correctly, have you noticed that your labels are not? Per the google api, they are placed evenly from start to finish. It's actually more complicated than you'd think, as you have to create all the intermediary values for the x-axis, making sure that there are corresponding blanks in the y-data, but still having labels. I'd post my solution, but I'm still working on it unfortunately :( Having some similar issues with this myself, and while you’ve got the values plotted along the x-axis correctly, have you noticed that your labels are not? Per the google api, they are placed evenly from start to finish.

It’s actually more complicated than you’d think, as you have to create all the intermediary values for the x-axis, making sure that there are corresponding blanks in the y-data, but still having labels.

I’d post my solution, but I’m still working on it unfortunately :(

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