Graph builder subset plots with the same axis labels

[#1]

Hello, 

I have a big data table and  a script to plot the subset by product. You can see the "where" in the script below.

I would like to keep the x-axis to be the same from product to product. The x-axis has two variables "PROC" and "CoreVoltage".    As you can see from the jpg file, at one "PROC", only some of the "CoreVoltage" showed up. How to show all the "PROC" and "CoreVoltage" combinations so from product to product the plots keep the same x-axis ? 

Names Default To Here( 1 );
dt = Current Data Table();
Summarize( dt, prodval = By( :"prod" ), );
n = N Items( prodval );
	
For(i = 1,i<=n,i ++,	
	Graph Builder(
		Size( 1790, 1234 ),
		Variables(
			X( :PROC ),
			X( :CoreVoltage, Position( 1 ) ),
			Y( :"Freq1"n )
		),
		Elements(
			Position( 1, 1 ),
			Heatmap( X( 1 ), X( 2 ), Y, Legend( 2 ), Label( "Label by Value" ) )
		),
		Where( :"prod" == prodval[i]),
		SendToReport(
			Dispatch(
				{},
				"PROC",
				ScaleBox,
				{Add Ref Line( 2, "Solid", "Green", "", 2 ),
				Add Ref Line( 6, "Solid", "Green", "", 2 ),
				Label Row( 1, {Inside Ticks( 1 ), Show Major Grid( 1 )} )}
				/*Label Row( 
					{Tick Mark( Label( "FF" ), Label( "0.57" ) ),
                    Tick Mark( Label( "FF" ), Label( "0.62" ) ),
                    Tick Mark( Label( "FF" ), Label( "0.97" ) )}
				 )}*/
			),
			Dispatch(
				{},
				"Freq1",
				ScaleBox,
				{Min( 1440), Max( 2440 ), Inc(20 ), Minor Ticks( 1 ),
				Label Row( {Show Major Grid( 1 ), Show Minor Grid( 1 )} )}
			),
			Dispatch(
			{},
			"graph title",
			TextEditBox,
			{Set Text( prodval[i] || " Freq vs. PROC & CoreVoltage" )}
			),
		)
	);
)

[#2]

- no need to use python to add the missing values ; )

- no need to add the missing values if you closely follow the tipps of @txnelson and  @jthi  : )

besides that, you could vote here:🙏 Column Property: Inclusive Values 
... with this feature there is no need anymore to add any missing values.

- but actually, no need to vote anymore : )