To plot the graph, need have XYZ data and another reference column to split the XYZ columns into different groups (layers in graph).

XY data should be M x N gridding. Origin will convert each XYZ block to a matrix using the Regular gridding method. If the data is not regular, the Sparse gridding method will be used to convert the XYZ data.

The Stacked Heatmap can be created from either a worksheet or matrix.