I am using GDAL and MODIS reprojection tool in my python project and want to know better way for math new indices of HDF data (MODIS data). Also I want to visualize them in web. Which format is more flexible for math and visualize my results?
As you can see from our website's Python example, you can directly access HDF with Python. Resolving lat/lon will be a little bit tricky for most MODIS products as illustrated in our NCL/IDL/MATLAB examples. However, you can use HDF-EOS2 dumper tool to dump lat/lon in ASCII files and read them back in Python.
Have you tried NCL? In my opinion, it's one of the easiest tool for MODIS data visualization and it can perform some math as well.