|Re: Bell Curve Chart in BIRT [message #965957 is a reply to message #957244]
||Wed, 31 October 2012 16:43
| Alex Rodriguez
Registered: October 2012
mark wen wrote on Thu, 25 October 2012 00:57|
Does anybody know how to generate Bell Curve (a.k.a normal distribution) chart in BIRT? This is not a built-in chart type.
Thanks in advance.
I have the same situation I need to generate a Bell Courve with BIRT, does any one know how to do it? From what I have seen in Excel methods:
1. You will have to have a set of data with a normal distribution
2. You will have to calculate Standar Deviation and the mean
3. You will have to grade the courve
For points 2 and 3 I think formulation expressions must be used as I do not see statistical functions in BIRT to calculate mean or Dev.
4. You will have to generate values according to the grading sections, the devstd and the mean. I'm trying to do it with cubes and expressions.
5. After you can generate a cube with the frecuency values according to grading, It could be possible to graph the Bell Courve using Scattered chart type.
I'm in the process of doing it but still working on it. The hard thing is creating the DevStd and Mean formulations.
This is what I'm trying following and Excel example I'm attaching, but still have not been able to finish it. I hope it helps.
If you have any luck please get back to me and give me a hand, If I get ti done I'll sure write to you via this forum.
Alex Rodriguez - Avanxo
|Re: Bell Curve Chart in BIRT [message #966141 is a reply to message #957244]
||Wed, 31 October 2012 19:54
| andrew smith
Registered: February 2012
Here is what I would recommend on this:|
all you need is a series of x,y pairs which when plotted produce the scatter plot.
The scatter plots are indeed supported by BIRT and BIRT is an excellent tool for plotting. Further BIRT's charging capabilities can be extended as well.
The following are the steps that you need to do:
1) Given \sigma (standard dev) and \mu (mean of the distribution), generate values of x that cover the region of interest. For example you could start with the following X vector: [-5,-4.9,....4.9,5]
2) Now that you have your x values, stick every one of them into the equation for normal destribution, so that you can produce correspoding y-values.
NOTE: now you have x,y pairs that define your distribution.
3) Next create a scripted data source. There is an excellent example on that on the BIRT's website
4) Next use scatter or a line chart and use your scripted datasource.
5) Once you run the report, you will see the normal distribution...
Hope this helps...
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