← All changes | flot/FAQ.txt +76 -75 1.2 → 1.9.2 View file →

		@@ -1,76 +1,76 @@
1		-Frequently asked questions
2		-
3		-Q: How much data can Flot cope with?
4		-
5		-A: 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.
9		-
10		-1000 points is not a problem, but as soon as you start having more
11		-points than the pixel width, you should probably start thinking about
12		-downsampling/aggregation as this is near the resolution limit of the
13		-chart anyway. If you downsample server-side, you also save bandwidth.
14		-
15		-
16		-Q: Flot isn't working when I'm using JSON data as source!
17		-
18		-A: Actually, Flot loves JSON data, you just got the format wrong.
19		-Double check that you're not inputting strings instead of numbers,
20		-like [["0", "-2.13"], ["5", "4.3"]]. This is most common mistake, and
21		-the error might not show up immediately because Javascript can do some
22		-conversion automatically.
23		-
24		-
25		-Q: Can I export the graph?
26		-
27		-A: This is a limitation of the canvas technology. There's a hook in
28		-the canvas object for getting an image out, but you won't get the tick
29		-labels. And it's not likely to be supported by IE. At this point, your
30		-best bet is probably taking a screenshot, e.g. with PrtScn.
31		-
32		-
33		-Q: The bars are all tiny in time mode?
34		-
35		-A: It's not really possible to determine the bar width automatically.
36		-So you have to set the width with the barWidth option which is NOT in
37		-pixels, but in the units of the x axis (or the y axis for horizontal
38		-bars). For time mode that's milliseconds so the default value of 1
39		-makes the bars 1 millisecond wide.
40		-
41		-
42		-Q: Can I use Flot with libraries like Mootools or Prototype?
43		-
44		-A: Yes, Flot supports it out of the box and it's easy! Just use jQuery
45		-instead of $, e.g. call jQuery.plot instead of $.plot and use
46		-jQuery(something) instead of $(something). As a convenience, you can
47		-put in a DOM element for the graph placeholder where the examples and
48		-the API documentation are using jQuery objects.
49		-
50		-Depending on how you include jQuery, you may have to add one line of
51		-code to prevent jQuery from overwriting functions from the other
52		-libraries, see the documentation in jQuery ("Using jQuery with other
53		-libraries") for details.
54		-
55		-
56		-Q: Flot doesn't work with [insert name of Javascript UI framework]!
57		-
58		-A: The only non-standard thing used by Flot is the canvas tag;
59		-otherwise it is simply a series of absolute positioned divs within the
60		-placeholder tag you put in. If this is not working, it's probably
61		-because the framework you're using is doing something weird with the
62		-DOM, or you're using it the wrong way.
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.
	1	+Frequently asked questions
	2	+--------------------------
	3	+
	4	+Q: How much data can Flot cope with?
	5	+
	6	+A: Flot will happily draw everything you send to it so the answer
	7	+depends on the browser. The excanvas emulation used for IE (built with
	8	+VML) makes IE by far the slowest browser so be sure to test with that
	9	+if IE users are in your target group.
	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	+Q: Flot isn't working when I'm using JSON data as source!
	18	+
	19	+A: 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	+Q: Can I export the graph?
	27	+
	28	+A: This is a limitation of the canvas technology. There's a hook in
	29	+the canvas object for getting an image out, but you won't get the tick
	30	+labels. And it's not likely to be supported by IE. At this point, your
	31	+best bet is probably taking a screenshot, e.g. with PrtScn.
	32	+
	33	+
	34	+Q: The bars are all tiny in time mode?
	35	+
	36	+A: It's not really possible to determine the bar width automatically.
	37	+So you have to set the width with the barWidth option which is NOT in
	38	+pixels, but in the units of the x axis (or the y axis for horizontal
	39	+bars). For time mode that's milliseconds so the default value of 1
	40	+makes the bars 1 millisecond wide.
	41	+
	42	+
	43	+Q: Can I use Flot with libraries like Mootools or Prototype?
	44	+
	45	+A: Yes, Flot supports it out of the box and it's easy! Just use jQuery
	46	+instead of $, e.g. call jQuery.plot instead of $.plot and use
	47	+jQuery(something) instead of $(something). As a convenience, you can
	48	+put in a DOM element for the graph placeholder where the examples and
	49	+the API documentation are using jQuery objects.
	50	+
	51	+Depending on how you include jQuery, you may have to add one line of
	52	+code to prevent jQuery from overwriting functions from the other
	53	+libraries, see the documentation in jQuery ("Using jQuery with other
	54	+libraries") for details.
	55	+
	56	+
	57	+Q: Flot doesn't work with [insert name of Javascript UI framework]!
	58	+
	59	+A: The only non-standard thing used by Flot is the canvas tag;
	60	+otherwise it is simply a series of absolute positioned divs within the
	61	+placeholder tag you put in. If this is not working, it's probably
	62	+because the framework you're using is doing something weird with the
	63	+DOM, or you're using it the wrong way.
	64	+
	65	+A common problem is that there's display:none on a container until the
	66	+user does something. Many tab widgets work this way, and there's
	67	+nothing wrong with it - you just can't call Flot inside a display:none
	68	+container as explained in the README so you need to hold off the Flot
	69	+call until the container is actually displayed (or use
	70	+visibility:hidden instead of display:none or move the container
	71	+off-screen).
	72	+
	73	+If you find there's a specific thing we can do to Flot to help, feel
	74	+free to submit a bug report. Otherwise, you're welcome to ask for help
	75	+on the forum/mailing list, but please don't submit a bug report to
	76	+Flot.