FAQ.md (3312B)
1 ## Frequently asked questions ## 2 3 #### How much data can Flot cope with? #### 4 5 Flot will happily draw everything you send to it so the answer 6 depends on the browser. The excanvas emulation used for IE (built with 7 VML) makes IE by far the slowest browser so be sure to test with that 8 if IE users are in your target group (for large plots in IE, you can 9 also check out Flashcanvas which may be faster). 10 11 1000 points is not a problem, but as soon as you start having more 12 points than the pixel width, you should probably start thinking about 13 downsampling/aggregation as this is near the resolution limit of the 14 chart anyway. If you downsample server-side, you also save bandwidth. 15 16 17 #### Flot isn't working when I'm using JSON data as source! #### 18 19 Actually, Flot loves JSON data, you just got the format wrong. 20 Double check that you're not inputting strings instead of numbers, 21 like [["0", "-2.13"], ["5", "4.3"]]. This is most common mistake, and 22 the error might not show up immediately because Javascript can do some 23 conversion automatically. 24 25 26 #### Can I export the graph? #### 27 28 You can grab the image rendered by the canvas element used by Flot 29 as a PNG or JPEG (remember to set a background). Note that it won't 30 include anything not drawn in the canvas (such as the legend). And it 31 doesn't work with excanvas which uses VML, but you could try 32 Flashcanvas. 33 34 35 #### The bars are all tiny in time mode? #### 36 37 It's not really possible to determine the bar width automatically. 38 So you have to set the width with the barWidth option which is NOT in 39 pixels, but in the units of the x axis (or the y axis for horizontal 40 bars). For time mode that's milliseconds so the default value of 1 41 makes the bars 1 millisecond wide. 42 43 44 #### Can I use Flot with libraries like Mootools or Prototype? #### 45 46 Yes, Flot supports it out of the box and it's easy! Just use jQuery 47 instead of $, e.g. call jQuery.plot instead of $.plot and use 48 jQuery(something) instead of $(something). As a convenience, you can 49 put in a DOM element for the graph placeholder where the examples and 50 the API documentation are using jQuery objects. 51 52 Depending on how you include jQuery, you may have to add one line of 53 code to prevent jQuery from overwriting functions from the other 54 libraries, see the documentation in jQuery ("Using jQuery with other 55 libraries") for details. 56 57 58 #### Flot doesn't work with [insert name of Javascript UI framework]! #### 59 60 Flot is using standard HTML to make charts. If this is not working, 61 it's probably because the framework you're using is doing something 62 weird with the DOM or with the CSS that is interfering with Flot. 63 64 A common problem is that there's display:none on a container until the 65 user does something. Many tab widgets work this way, and there's 66 nothing wrong with it - you just can't call Flot inside a display:none 67 container as explained in the README so you need to hold off the Flot 68 call until the container is actually displayed (or use 69 visibility:hidden instead of display:none or move the container 70 off-screen). 71 72 If you find there's a specific thing we can do to Flot to help, feel 73 free to submit a bug report. Otherwise, you're welcome to ask for help 74 on the forum/mailing list, but please don't submit a bug report to 75 Flot.