rewrite matrices

[jdcaicedo251]

Is there a way I can modify the values of one matrix and store it again under the same name?

In the example, I tried:
halves = np.array(m1) * 0.5

and then:
myfile['m1']=halves

But this generates an error
NodeError: group ``/data`` already has a child node named 'm1'

In the API, I don't see an option to delete a matrix. This would allow me to use the "create_matrix" function.

[bstabler]

You can drop a matrix using the pytables API

import tables
f = tables.open_file('myfile.omx', 'a')
f.remove_node("/data/MATNAME")