How to plot heatmap with matplotlib?

` Dear all,

    Heatmap (like those on the page ``        )

is a frequently used type of image in microarray data analysis.
However, it seems there are no convenient functions in
matplotlib to plot heatmap (please correct me if I was wrong),
so I’m planning to write my own.
Let me take the heatmap by the link as an example, which is produced by R. With my limited knowledge and expertise of matplotlib, I have the following questions and I hope you guys could help me.

    1) I tend to use pcolor to draw the colormap in the central

area. However, I’ve seen a lot of examples draw colormap with

  ``           What's the difference between pcolor and imshow?

       Shall I use pcolor or imshow to produce the heatmap in the

link above?

    2) How to draw the dendrograms on the top and left of the


  ``           I got hints from on how to append axes to current plot, but I still have now idea

how to draw the dengrograms.
3) How to draw the column side colormap (the smaller one)
between the top dendrogram and the big colormap?

    4) I can use colorbar to draw a colorbar, but how to place the

colorbar on the topleft of the image just as the R heatmap does?

    5) Any other suggestions on how to draw the heatmap?


    Thanks and any help will be greatly appreciated.