Date Range Google Chart Tools

问题:

I'm trying to display data on a line graph using Google Charts. The data displays fine, however I would like to set a date range to be displayed.

The data is sent from the database in a JSON literal format:

{
    "cols": [
                {"label": "Week", "type": "date"},
                {"label": "Speed", "type": "number"},               
                {"type":"string","p":{"role":"tooltip"}},   
                {"type":"string","p":{"role":"tooltip"}},   
                {"type":"string","p":{"role":"tooltip"}},   
                {"type":"string","p":{"role":"tooltip"}},   

            ],
    "rows": [
               {"c":[{"v": "Date('.$date.')"},{"v": null},{"v": null},{"v": null},{"v": null},{"v": null}]},
               {"c":[{"v": "Date('.$date.')"},{"v": null},{"v": null},{"v": null},{"v": null},{"v": null}]}
            ] 
}

Data is either displayed by week or month (null for easy reading) for example this week:

2012, 02, 06
2012, 02, 07
2012, 02, 09 

Data isn't set for everyday of the week, therefore in this example only the dates above are shown. What I would like to be shown is the start of the week (2012, 02, 06) to the end of the week (2012, 02, 12) similar to the third example here.

I managed to get the whole week showing by checking if the date exists in the database and if not append an extra row will null data, this however meant the line was not continuous and the dates where not in order.

Could anyone offer any advice on how to I could go about doing this?

Thanks!

回答1:

Did you try leaving the missing dates be missing dates (i.e. let the database return 2 values instead of 7)?

The continuous axis should handle missing dates, you just need to set the axis range from start to end of the week.

UPDATE

for interactive line chart the axis ranges can be set like this (as inspired by this thread):

hAxis: {...
        viewWindowMode: 'explicit',
        viewWindow: {min: new Date(2007,1,1),
                     max: new Date(2010,1,1)}
        ...}

see http://jsfiddle.net/REgJu/

回答2:

"I managed to get the whole week showing by checking if the date exists in the database and if not append an extra row will null data, this however meant the line was not continuous and the dates where not in order."

I think you are on the right track you just need to do it in a slightly different way. I have the function like the below to make data continuous.

$data = array(
    1 => 50,
    2 => 75,
    4 => 65,
    7 => 60,
);
$dayAgoStart = 1;
$daysAgoEnd = 14;

$continuousData = array();

for($daysAgo=$daysAgoStart ; $daysAgo<=$daysAgoEnd ; $daysAgo++){
    if(array_key_exists($daysAgo, $data) == true){
        $continuousData[$daysAgo] = $data[$daysAgo];
    }
    else{
        $continuousData[$daysAgo] = 0;
    }
}

continuousData will now hold:

$data = array(
    1 => 50,
    2 => 75,
    3 => 0,
    4 => 65,
    5 => 0,
    6 => 0,
    7 => 60,
    8 => 0,
    9 => 0,
    10 => 0,
    11 => 0,
    12 => 0,
    13 => 0,
    14 => 0,
);

in that order, and then the data can be used in the charts without any gaps.

回答3:

Perhaps you can use a different chart type? Dygraphs looks like it might be helpful.

Otherwise you may have to write your own custom chart type.