store/load numpy array from binary files
- by Javier
Dear all,
I would like to store and load numpy arrays from binary files. For that purposes, I created two small functions. Each binary file should contain the dimensionality of the given matrix.
def saveArrayToFile(data, fileName):
with open(fileName, 'w') as file:
a = array.array('f')
nSamples, ndim = data.shape
a.extend([nSamples, ndim]) # write number of elements and dimensions
a.fromstring(data.tostring())
a.tofile(file)
def readArrayFromFile(fileName):
_featDesc = np.fromfile(fileName, 'f')
_ndesc = int(_featDesc[0])
_ndim = int(_featDesc[1])
_featDesc = _featDesc[2:]
_featDesc = _featDesc.reshape([_ndesc, _ndim])
return _featDesc, _ndesc, _ndim
An example on how to use the functions is:
myarr=np.array([[7, 4],[3, 9],[1, 3]])
saveArrayToFile(myarr,'myfile.txt')
_featDesc, _ndesc, _ndim = readArrayFromFile('myfile.txt')
However, an error message of 'ValueError: total size of new array must be unchanged' is shown. My arrays can be of size MxN and MxM. Any suggestions are more than welcomed.
I think the problem might be in the saveArrayToFile function.
Best wishes,
Javier
