python - float64 to float32 Cython Error -

-

i've created cython code make matrix operations between dense matrix , sparse vector,as follows (as i'm learning cython i'm not sure code, it's best come far):

import numpy np cimport numpy np ctypedef np.float64_t dtype_t ctypedef np.int32_t dtypei_t cimport cython  @cython.boundscheck(false) @cython.wraparound(false) @cython.nonecheck(false) def cdensexsparse(np.ndarray[dtype_t, ndim = 2] y,                   np.ndarray[dtype_t, ndim = 1] v,                   np.ndarray[dtypei_t, ndim = 1] i,                   np.ndarray[dtype_t, ndim = 1] = none):     """     computes = y * (v_i)     """     if y none:         raise valueerror("input cannot null")     = np.zeros(y.shape[1])     cdef py_ssize_t i, indice     cdef dtype_t s       in range(a.shape[0]):                      s = 0         indice in range(len(i)):             s += y[i[indice], i] * v[indice]         a[i] = s     return

it works fine. when change third line from:

ctypedef np.float64_t dtype_t

to:

ctypedef np.float32_t dtype_t

and compile .pyx file , run again matrix operations error:

"buffer dtype mismatch, expected 'dtype_t' got 'long'"

as example, when compiling using np.float32_t , running code:

in [3]: numpy import random rd, array, int32, float32  in [4]: y = array(rd.rand(10, 200), dtype = float32)  in [5]: v = array([1, 2, 3], dtype = float32)  in [6]: = array([0, 1, 2], dtype = int32)   in [7]: cdensexsparse import cdensexsparse  in [8]: r = cdensexsparse(y, v, i) --------------------------------------------------------------------------- valueerror                                traceback (most recent call last) <ipython-input-8-319f9c8c8d49> in <module>() ----> 1 r = cdensexsparse(y, v, i)  /home/will/workspace/s3_recsys/svd/cdensexsparse.so in cdensexsparse.cdensexsparse     (cdensexsparse.c:1484)()  valueerror: buffer dtype mismatch, expected 'dtype_t' got 'double'

is there different way use float32 in cython? using float64 , float32 shouldn't work same way?

for i've researched far should work same, didn't in code.

thanks in advance!

the default behaviour of np.zeros create float64 data, if want force datatype float32 should specify it. should put cdefs in beginning of function.


Comments

Post a Comment

Popular posts from this blog

c# - How Configure Devart dotConnect for SQLite Code First? -

-
can configure following sample code ? when run following code, error : no entity framework provider found ado.net provider invariant name 'devart.data.sqlite' setting in machine.config <system.data> <dbproviderfactories> <add name="dotconnect sqlite" invariant="devart.data.sqlite" description="devart dotconnect sqlite" type="devart.data.sqlite.sqliteproviderfactory, devart.data.sqlite, version=4.6.287.0, culture=neutral, publickeytoken=09af7300eec23701" /> </dbproviderfactories> </system.data> after add below block code in app.config <?xml version="1.0"?> <configuration>   <configsections> <!-- more information on entity framework configuration, visit http://go.microsoft.com/fwlink/?linkid=237468 --> <section name="entityframework" type="system.data.entity.internal.configfile.entityframeworksection, entit...
Read more

java - Copying object fields -

-
what best way of copying classes when need have 2 independent variables? have simple class: public class myclass { boolean = false; string b= "not empty"; } do need make method : assign(myclass data ) { a= data.a; b= data.b; } is there automatic method copy (duplicate) objects in java? do need make method : pretty close. instead of making method, should make constructor. such constructors called copy constructor , , create them this: myclass(myclass data) { = data.a; b = data.b; } and create copy of instance, use constructor this: myclass obj1 = new myclass(); myclass obj2 = new myclass(obj1); copy constructor can tedious : using copy constructor create deep-copy can tedious, when class has mutable fields. in case, assignment create copy of reference, , not object itself. have create copy of fields (if want deep copy). can go recursive. a better way create deep copy serialize , deserialize object. why not use clone()? ...
Read more

c++ - Clear the memory after returning a vector in a function -

-
i have function processes , stores lot of data in , returns results vector of class. amount of data stored in function tremendous , want clear storage memory of function after finished job. necessary (does function automatically clear memory) or should clear memory function? update: vector<customers> process(char* const *filename, vector<int> id) { vector<customers> list_of_customers; (perform actions) return list_of_customers; } variables defined locally within function automatically released @ end of function scope. destructors objects called, should free memory allocated objects (if objects coded correctly). example of such object std::vector . anything you've allocated new must have corresponding delete release storage. try avoid doing own allocation , use raii instead, i.e. containers or smart pointers.
Read more