/// <summary>
/// Returns the content of the Rexp as a matrix of doubles (2D-array: m[rows][cols]).
/// </summary>
/// <returns>2D array of doubles in the form double[rows][cols] or
/// <code>null</code> if the contents is no 2-dimensional matrix of doubles
/// </returns>
/// <example>Double[,] m=RconnectionObject.Eval("matrix(c(1,2,3,4,5,6),2,3)").AsDoubleMatrix();</example>
public Double[,] AsDoubleMatrix()
{
if ((type != Xpression.XT_ARRAY_DOUBLE) || (rattribute == null) ||
(rattribute.Xtype != Xpression.XT_LIST))
{
return(null);
}
Rexp dim = rattribute.AsList().Head;
if (dim == null || dim.Xtype != Xpression.XT_ARRAY_INT)
{
return(null); // we need dimension attr
}
Int32[] ds = dim.AsIntArray();
if (ds == null || ds.Length != 2)
{
return(null); // matrix must be 2-dimensional
}
Int32 m = ds[0];
Int32 n = ds[1];
Double[,] r = new Double[m, n];
Double[] ct = AsDoubleArray();
if (ct == null)
{
return(null);
}
// R stores matrices as matrix(c(1,2,3,4),2,2) = col1:(1,2), col2:(3,4)
// we need to copy everything, since we create 2d array from 1d array
Int32 k = 0;
for (int i = 0; i < m; i++)
{
for (int j = 0; j < n; j++)
{
r[i, j] = ct[k++];
}
}
return(r);
}