Convert numpy array type and values from Float64 to Float32

Question

I am trying to convert threshold array(pickle file of isolation forest from scikit learn) of type from Float64 to Float32

for i in range(len(tree.tree_.threshold)):     tree.tree_.threshold[i] = tree.tree_.threshold[i].astype(np.float32) 

​ Then Printing it

for value in tree.tree_.threshold[:5]:     print(type(value))     print(value) 

the output i am getting is :

<class 'numpy.float64'> 526226.0 <class 'numpy.float64'> 91.9514312744 <class 'numpy.float64'> 3.60330319405 <class 'numpy.float64'> -2.0 <class 'numpy.float64'> -2.0 

I am not getting a proper conversion to Float32. I want to convert values and their type to Float32, Did anybody have any workaround this ?

Answer 1

The problem is that you do not do any type conversion of the numpy array. You calculate a float32 variable and put it as an entry into a float64 numpy array. numpy then converts it properly back to float64

Try someting like this:

a = np.zeros(4,dtype="float64")  print a.dtype print type(a[0]) a = np.float32(a) print a.dtype print type(a[0]) 

The output (tested with python 2.7)

float64 <type 'numpy.float64'> float32 <type 'numpy.float32'> 

a is in your case the array tree.tree_.threshold

Answer 2

You can try this:

tree.tree_.threshold[i]=tree.tree_.threshold[i].astype('float32',casting='same_kind’)