Component and null inputs

Hi all, I  am playing with component in C#. The component is working fine, except that I need to informed all my inputs to get the ouputs.

It seems like if one of the inputs is not informed the component doesn't run..

I would to be free to informed/or not the inputs data.

So if there is an input value returns the output and if the input value is null just don't care.

Can someone help me ?

thx

public class myComponent : Grasshopper.Kernel.GH_Component
{
public myComponent()
: base("MyComponent", "MTC", "My Component", "Extra", "Simple")
{
}


//INPUTS
protected override void RegisterInputParams(Grasshopper.Kernel.GH_Component.GH_InputParamManager pManager)
{
pManager.Register_DoubleParam("Double1", "D1", "Double 1");
pManager.Register_DoubleParam("Double2", "D2", "Double 2");
pManager.Register_DoubleParam("Double3", "D3", "Double 3");
}

//OUPUTS
protected override void RegisterOutputParams(Grasshopper.Kernel.GH_Component.GH_OutputParamManager pManager)
{
pManager.Register_DoubleParam("Double1_out", "D1_out", "Double 1 output");
pManager.Register_DoubleParam("Double2_out", "D2_out", "Double 2 output");
pManager.Register_DoubleParam("Double3_out", "D3_out", "Double 3 output");
}

//SOLVE
protected override void SolveInstance(Grasshopper.Kernel.IGH_DataAccess DA)
{
double data1 = double.NaN;
double data2 = double.NaN;
double data3 = double.NaN;

double data1_out = double.NaN;
double data2_out = double.NaN;
double data3_out = double.NaN;

//if (!DA.GetData(0, ref data1)) { return; }
//if (!DA.GetData(1, ref data2)) { return; }
//if (!DA.GetData(2, ref data3)) { return; }

DA.GetData(0, ref data1);
DA.GetData(1, ref data2);
DA.GetData(2, ref data3);

if (data1 != double.NaN)
{
data1_out = data1 + 10;
DA.SetData(0, data1_out);
}


if (data2 != double.NaN)
{
data2_out = data2 + 10;
DA.SetData(1, data2_out);
}


if (data3 != double.NaN)
{
data3_out = data3 + 10;
DA.SetData(2, data3_out);
}



}

//GUID
public override Guid ComponentGuid
{
get { return new Guid("3fc7a1e5-5645-427c-8525-da87867f4a3f"); }
}

}