root / hci / trunk / eneraptor-web-app / web-app / js / flot / FAQ.txt @ 11
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1 | 11 | alexbesir | Frequently asked questions |
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2 | -------------------------- |
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4 | Q: How much data can Flot cope with? |
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5 | |||
6 | A: Flot will happily draw everything you send to it so the answer |
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7 | depends on the browser. The excanvas emulation used for IE (built with |
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8 | VML) makes IE by far the slowest browser so be sure to test with that |
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9 | if IE users are in your target group. |
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11 | 1000 points is not a problem, but as soon as you start having more |
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12 | points than the pixel width, you should probably start thinking about |
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13 | downsampling/aggregation as this is near the resolution limit of the |
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14 | chart anyway. If you downsample server-side, you also save bandwidth. |
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17 | Q: Flot isn't working when I'm using JSON data as source! |
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18 | |||
19 | A: Actually, Flot loves JSON data, you just got the format wrong. |
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20 | Double check that you're not inputting strings instead of numbers, |
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21 | like [["0", "-2.13"], ["5", "4.3"]]. This is most common mistake, and |
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22 | the error might not show up immediately because Javascript can do some |
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23 | conversion automatically. |
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24 | |||
25 | |||
26 | Q: Can I export the graph? |
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27 | |||
28 | A: This is a limitation of the canvas technology. There's a hook in |
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29 | the canvas object for getting an image out, but you won't get the tick |
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30 | labels. And it's not likely to be supported by IE. At this point, your |
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31 | best bet is probably taking a screenshot, e.g. with PrtScn. |
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32 | |||
33 | |||
34 | Q: The bars are all tiny in time mode? |
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35 | |||
36 | A: It's not really possible to determine the bar width automatically. |
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37 | So you have to set the width with the barWidth option which is NOT in |
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38 | pixels, but in the units of the x axis (or the y axis for horizontal |
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39 | bars). For time mode that's milliseconds so the default value of 1 |
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40 | makes the bars 1 millisecond wide. |
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41 | |||
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43 | Q: Can I use Flot with libraries like Mootools or Prototype? |
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44 | |||
45 | A: Yes, Flot supports it out of the box and it's easy! Just use jQuery |
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46 | instead of $, e.g. call jQuery.plot instead of $.plot and use |
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47 | jQuery(something) instead of $(something). As a convenience, you can |
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48 | put in a DOM element for the graph placeholder where the examples and |
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49 | the API documentation are using jQuery objects. |
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50 | |||
51 | Depending on how you include jQuery, you may have to add one line of |
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52 | code to prevent jQuery from overwriting functions from the other |
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53 | libraries, see the documentation in jQuery ("Using jQuery with other |
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54 | libraries") for details. |
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55 | |||
56 | |||
57 | Q: Flot doesn't work with [widget framework xyz]! |
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58 | |||
59 | A: The problem is most likely within the framework, or your use of the |
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60 | framework. |
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61 | |||
62 | The only non-standard thing used by Flot is the canvas tag; otherwise |
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63 | it is simply a series of absolute positioned divs within the |
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64 | placeholder tag you put in. If this is not working, it's probably |
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65 | because the framework you're using is doing something weird with the |
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66 | DOM. As a last resort, you might try replotting and see if it helps. |
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67 | |||
68 | If you find there's a specific thing we can do to Flot to help, feel |
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69 | free to submit a bug report. Otherwise, you're welcome to ask for help |
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70 | on the mailing list, but please don't submit a bug report to Flot - |
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71 | try the framework instead. |