Global scaling for multiple Y-axes

I plot a chart with multiple Y-axes and I have a problem to scale that with a common value.

For example, I have 2 Y-axes und I just want to render the first Y-axis, the plot of the second Y-axis doesn't scale in the first one correctly. If you set the same scale for both axes, it's shown correctly. But I just want to set a common scale...

Is there a solution for this problem?

Thx

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Comments

mwilliams

You could probably loop through the axes in your script and set them there.

chris_w

Mhhhh, ok... I have to calculate the MAX value in my Java Code...
How do i get this value in my event java script context?

Is it possible to fire database queries within the java script events?

mwilliams

You can grab the max value in the afterDataSetFilled function in the chart script like in the attached report. Then, you should be able to set the scale based on this.

chris_w

Thank you sir, that sounds good. I will try that...

mwilliams

Ok. Let me know if you run into issues!

chris_w

Hi, it works to retrieve the max value of the dataset. 
In the next step I tried to set the max value to the axes using beforeDrawAxisLabel phase. 
I'm not sure where to set... 
 
<pre class='_prettyXprint _lang-auto _linenums:0'>
function afterDataSetFilled(series, dataSet, icsc){

importPackage( Packages.java.io );
importPackage( Packages.org.eclipse.birt.chart.model.type.impl );
importPackage( Packages.org.eclipse.birt.chart.util);
importPackage( Packages.java.util );

ps = PluginSettings.instance( );

if(series.getClass() == BarSeriesImpl){

dsp = ps.getDataSetProcessor(series.getClass());
//dataset max
var mmax = dsp.getMaximum(dataSet);
var existingMax = icsc.getExternalContext().getScriptable().getGlobalVariable("MaxBarValue");

if(mmax != null && existingMax < mmax){
mmax = Math.round(mmax);

while(mmax % 10 != 0){
mmax++;
}
icsc.getExternalContext().getScriptable().setGlobalVariable("MaxBarValue", mmax);
}
} else {
}

/**
* Called before rendering each label on a given Axis.
*
* @param axis
* Axis
* @param label
* Label
* @param icsc
* IChartScriptContext
*/
function beforeDrawAxisLabel(axis, label, icsc){

importPackage( Packages.org.eclipse.birt.chart.model.component.impl );
importPackage( Packages.org.eclipse.birt.chart.model.data.impl );

var max = icsc.getExternalContext().getScriptable().getGlobalVariable("MaxBarValue");
axis.getScale().setMax(NumberDataElementImpl.create(max));
}
</pre>

chris_w

Code to scale all Y-Axis to one common scale value on a generic way using BIRT scripting: 
 
<pre class='_prettyXprint _lang-auto _linenums:0'>function afterDataSetFilled(series, dataSet, icsc){

importPackage(Packages.java.io);
importPackage(Packages.org.eclipse.birt.chart.model.type.impl);
importPackage(Packages.org.eclipse.birt.chart.util);
importPackage(Packages.java.util);
importPackage(Packages.org.eclipse.birt.chart.model.data.impl);
importPackage(Packages.org.eclipse.birt.chart.model.component.impl);
importPackage(Packages.org.eclipse.birt.chart.model.attribute);
importPackage(Packages.org.eclipse.birt.chart.model.attribute.impl);

ps = PluginSettings.instance( );

if(series.getClass() == BarSeriesImpl){

dsp = ps.getDataSetProcessor(series.getClass());
//dataset max
var mmax = dsp.getMaximum(dataSet);

var existingMax = icsc.getExternalContext().getScriptable().getGlobalVariable("MaxSliceValue");

if(mmax != null && existingMax < mmax){

mmax = Math.round(mmax);

if(mmax < 120){
mmax = 120;
}

while(mmax % 20 != 0){
mmax++;
}

icsc.getExternalContext().getScriptable().setGlobalVariable("MaxSliceValue", mmax);

chart = icsc.getChartInstance();

var yAxisSize = chart.getBaseAxes().length;

while(yAxisSize != 0){
yAxisSize--;
xAxis = chart.getBaseAxes()[yAxisSize];
var xAxisSize = chart.getOrthogonalAxes(xAxis, true).length;
while(xAxisSize != 0){
xAxisSize--;
yAxis = chart.getOrthogonalAxes(xAxis, true)[xAxisSize];
yscale = yAxis.getScale();
yscale.setMin( NumberDataElementImpl.create(0));
yscale.setMax(NumberDataElementImpl.create(mmax));
yAxis.setScale(yscale);
}
}
}
}
}</pre>

mwilliams

Here's an example that does it with afterDataSetFilled and beforeGeneration.