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Dynamically add a marker line to a chart [message #725746]

Thu, 15 September 2011 12:29

Eclipse User

Hi,

I have a Chart with bar series. I would like place a vertical marker line on a point on the X axis to denote a cut-off point. Is there a way to do this in the chart script given that the cut-off point is not known until runtime. I can retrieve it from a global variable.

Re: Dynamically add a marker line to a chart [message #726125 is a reply to message #725746]

Fri, 16 September 2011 12:03

Eclipse User

Here is an example that sets the location based on a parameter.

Jason

On 9/15/2011 12:29 PM, Mike Wulkan wrote:
> Hi,
>
> I have a Chart with bar series. I would like place a vertical marker
> line on a point on the X axis to denote a cut-off point. Is there a way
> to do this in the chart script given that the cut-off point is not known
> until runtime. I can retrieve it from a global variable.
>
>

Attachment: markerlinebasedonparm.zip
(Size: 6.15KB, Downloaded 712 times)

Re: Dynamically add a marker line to a chart [message #726177 is a reply to message #726125]

Fri, 16 September 2011 14:10

Eclipse User

Thanks for this Jason. One problem though. In my chart I have a bunch of series but only one data value per series. The marker I'd like to insert is between to series bars not between two groups of series. Is this possible?

Re: Dynamically add a marker line to a chart [message #726777 is a reply to message #726177]

Mon, 19 September 2011 10:36

Eclipse User

Mike,

Can you take a screenshot of where the marker line is, and use paint to
show where you want it?

Jason

On 9/16/2011 2:10 PM, Mike Wulkan wrote:
> Thanks for this Jason. One problem though. In my chart I have a bunch of
> series but only one data value per series. The marker I'd like to insert
> is between to series bars not between two groups of series. Is this
> possible?

Re: Dynamically add a marker line to a chart [message #727099 is a reply to message #726777]

Tue, 20 September 2011 08:14

Eclipse User

The green line is where the marker line comes out but the red line is where I want it. The problem is that all the bars are from different series and there is only one row so the x axis only has one point on it.

Attachment: markerlines.png
(Size: 9.06KB, Downloaded 2710 times)

Re: Dynamically add a marker line to a chart [message #727170 is a reply to message #727099]

Tue, 20 September 2011 10:52

Eclipse User

Mike,

Add the following beforeDrawMarkerLine script:

function beforeDrawMarkerLine( axis, markerLine, icsc )
{
importPackage(Packages.org.eclipse.birt.chart.model.component.impl);
importPackage(Packages.org.eclipse.birt.chart.model.data.impl);
importPackage(Packages.org.eclipse.birt.chart.model.attribute);
importPackage(Packages.org.eclipse.birt.chart.model.attribute.impl);
importPackage(Packages.org.eclipse.birt.chart.util);
markerLine.setValue(NumberDataElementImpl.create(0.5));

}

On 9/20/2011 8:14 AM, Mike Wulkan wrote:
> The green line is where the marker line comes out but the red line is where I want it. The problem is that all the bars are from different series and there is only one row so the x axis only has one point on it.

Re: Dynamically add a marker line to a chart [message #727479 is a reply to message #727170]

Wed, 21 September 2011 08:15

Eclipse User

Hi Jason,

Doh! For some reason my mind was stuck on integral values... this was just too easy. Well actually it was too easy. In actual fact I don't want the marker line at the halfway point. I'd like to place it on the right edge of the 2nd bar (as shown by the arrow). I'm not sure how to calculate this offset and tie it to the number of bars. I tried multiples of 6 (number of bars) and multiples of 7 (number of edges). The image shown is 3*(1/7) but as you can see it places the marker a little too far to the right. Is there an easy formula I can use or do I just have to fudge it and hardcode a value that works?
index.php/fa/4016/0/

Attachment: markersample.png
(Size: 8.82KB, Downloaded 2625 times)

Re: Dynamically add a marker line to a chart [message #727633 is a reply to message #727479]

Wed, 21 September 2011 13:54

Eclipse User

That is a bit more complicated. Look at the attached example.

Jason

On 9/21/2011 8:15 AM, Mike Wulkan wrote:
> Hi Jason,
>
> Doh! For some reason my mind was stuck on integral values... this was just too easy. Well actually it was too easy. In actual fact I don't want the marker line at the halfway point. I'd like to place it on the right edge of the 2nd bar (as shown by the arrow). I'm not sure how to calculate this offset and tie it to the number of bars. I tried multiples of 6 (number of bars) and multiples of 7 (number of edges). The image shown is 3*(1/7) but as you can see it places the marker a little too far to the right. Is there an easy formula I can use or do I just have to fudge it and hardcode a value that works?
>

Attachment: optionalgroupingmarkerline.zip
(Size: 4.55KB, Downloaded 348 times)

Re: Dynamically add a marker line to a chart [message #728077 is a reply to message #727633]

Thu, 22 September 2011 09:50

Eclipse User

Hi Jason,

I think this is getting closer but my chart is configured a little differently and the code you supplied doesn't appear to calculate the correct positions. I have included a sample chart with the configuration that I am using and the arrow points to where I would like the marker line to be positioned. The actual marker line is where the current code puts it.

index.php/fa/4033/0/

Attachment: markersample.png
(Size: 10.18KB, Downloaded 2705 times)
Attachment: positionMarkerLine.rptdesign
(Size: 93.84KB, Downloaded 503 times)

Re: Dynamically add a marker line to a chart [message #728216 is a reply to message #728077]

Thu, 22 September 2011 14:12

Eclipse User

Can you lower the unit spacing (which is getting added per series).
See modified example.

Jason

On 9/22/2011 9:50 AM, Mike Wulkan wrote:
> Hi Jason,
>
> I think this is getting closer but my chart is configured a little differently and the code you supplied doesn't appear to calculate the correct positions. I have included a sample chart with the configuration that I am using and the arrow points to where I would like the marker line to be positioned. The actual marker line is where the current code puts it.
>
>

Attachment: MikeW.zip
(Size: 6.15KB, Downloaded 385 times)

Re: Dynamically add a marker line to a chart [message #728527 is a reply to message #728216]

Fri, 23 September 2011 08:32

Eclipse User

Hi Jason,

This almost works. The example works but when I applied this code to my actual chart the line was still out (to the right). So I went back and forth a million times to try to figure out what the difference was. I finally figured it out that it was the legend. In my actual chart code I had different place holder names for each of the series which I subsequently modified in my beforeDrawLegendItem script. One of the place holder names was long (eg., "Brobdingnagian"). The chart formatted based on the width of the legend as it was specified in the designer. At runtime the width of the legend was actually smaller which threw out the calculations for the marker.

I have worked around this by changing the place holder names to something shorter since they don't actually display anyway, but for future reference, I was wondering if there was still a minor tweak to the code that would account for this?

Re: Dynamically add a marker line to a chart [message #728654 is a reply to message #728527]

Fri, 23 September 2011 11:35

Eclipse User

Mike,

You can get the size of any the chart blocks (plot, legend, title etc)
but I am not certain how you would do the calculation.

Jason

On 9/23/2011 8:32 AM, Mike Wulkan wrote:
> Hi Jason,
>
> This almost works. The example works but when I applied this code to my
> actual chart the line was still out (to the right). So I went back and
> forth a million times to try to figure out what the difference was. I
> finally figured it out that it was the legend. In my actual chart code I
> had different place holder names for each of the series which I
> subsequently modified in my beforeDrawLegendItem script. One of the
> place holder names was long (eg., "Brobdingnagian"). The chart formatted
> based on the width of the legend as it was specified in the designer. At
> runtime the width of the legend was actually smaller which threw out the
> calculations for the marker.
>
> I have worked around this by changing the place holder names to
> something shorter since they don't actually display anyway, but for
> future reference, I was wondering if there was still a minor tweak to
> the code that would account for this?

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