24 bit signed integer binary conversion help needed
hi; I am trying to read 24bit signed WAV format (little endian) data from a WAV file and convert it to 32 bit little endian integer format ... can anybody please tell me how to do the conversion from 24 bit to 32 bit with a snippet of Python code ??? Thanks so much Robert Somerville -- http://mail.python.org/mailman/listinfo/python-list
24 bit signed integer binary conversion help needed
thanks Grant, your sext24 function does the trick (this Python newbie thanks you a lot ...) so i loop on d=wave.readframes(1) call dd=sext24(d) on the frame read , then unpack(dd) the output of sext24 into a 32bit integer (seems to do the trick correctly for signed 24 bit integers ) > On 2010-01-08, Robert Somerville <rsomerville at sjgeophysics.com> wrote: > >> I am trying to read 24bit signed WAV format (little endian) data from a >> WAV file and convert it to 32 bit little endian integer format ... can >> anybody please tell me how to do the conversion from 24 bit to 32 bit >> with a snippet of Python code ??? > > def sext24(d): > if ord(d[2]) & 0x80: > return d+'\xff' > else: > return d+'\x00' -- http://mail.python.org/mailman/listinfo/python-list
24 bit signed integer binary conversion help needed
thanks Grant, your sext24 function does the trick (this Python newbie
thanks you a lot ...)
so i loop on d=wave.readframes(1)
call dd=sext24(d) on the frame read , then
ddd=struct.unpack("<%ul" % 1 ,dd)
unpack(dd) the output of sext24 into a 32bit integer (seems to do the
trick correctly for signed 24 bit integers )
-thanks , bob
--
http://mail.python.org/mailman/listinfo/python-list
how to sort two dimensional array
Hi; i am having trouble trying to sort the rows of a 2 dimensional array by the values in the first column .. does anybody know how or have an example of how to do this ??? while leaving the remain columns remain relative to the leading column from numpy import * a=array( [ [4, 4, 3], [4, 5, 2], [3, 1, 1] ] ) i would like to generate the output (or get the output ...) b = [ [3,1,1], [4,4,3], [4,5,2] ] thanks; bob -- http://mail.python.org/mailman/listinfo/python-list
how to sort two dimensional array ??
Hi; i am having trouble trying to sort the rows of a 2 dimensional array by the values in the first column .. does anybody know how or have an example of how to do this ??? while leaving the remain columns remain relative to the leading column from numpy import * a=array( [ [4, 4, 3], [4, 5, 2], [3, 1, 1] ] ) i would like to generate the output (or get the output ...) b = [ [3,1,1], [4,4,3], [4,5,2] ] thanks; bob -- http://mail.python.org/mailman/listinfo/python-list
how to sort two dimensional array ??
Hi; i am having trouble trying to sort the rows of a 2 dimensional array by the values in the first column .. does anybody know how or have an example of how to do this ??? while leaving the remain columns remain relative to the leading column from numpy import * a=array( [ [4, 4, 3], [4, 5, 2], [3, 1, 1] ] ) i would like to generate the output (or get the output ...) b = [ [3,1,1], [4,4,3], [4,5,2] ] thanks; bob -- http://mail.python.org/mailman/listinfo/python-list
Elementtree install problem in Ubuntu (a newbie ..)
Hi ; I installed the elementtree and celementree packages throught the synaptic package manager, all seems to go fine through the install ... when i startup python and try to import them (as per the EFFBOTT.org suggestions) .. PROBLEMS ... (see below ..) What am i doing wrong ??? this is a new window after installation of packages ... Python 2.6.4 (r264:75706, Dec 7 2009, 18:43:55) [GCC 4.4.1] on linux2 Type "help", "copyright", "credits" or "license" for more information. >>> import elementtree.ElementTree as ET Traceback (most recent call last): File "", line 1, in ImportError: No module named elementtree.ElementTree >>> import elementtree Traceback (most recent call last): File "", line 1, in ImportError: No module named elementtree thanks; Robert somerville -- http://mail.python.org/mailman/listinfo/python-list
Python 2.6 and modules dbi AND odbc
hi; i am trying to get some legacy python code (which i no nothing about) working with tries to import dbi and odbc (the import fails ...) it looks like these modules are deprecated ?? if so is there a work around , if not deprecated, what am i doing wrong ?? i see no Ubuntu packages that look promising .. Robert Somerville -- http://mail.python.org/mailman/listinfo/python-list
problems creating and adding class instances to a list:
I am trying to create a list of consisting of multiple instances of the same class, The Problems i am having is that i seem to be accessing the same memory.. How should i solve this Python problem ? Here is some sample code demonstraing my problem (same memory) : from copy import copy as cp class ctest(): x = int y = [1,2,3] def return_class(i): d = ctest() d.y[1] = i*10 return (d) if __name__ == '__main__': c_list= [] print 'len-a =',len(c_list) for i in range(5): e = cp(return_class(i)) c_list.append(e) print 'i= ',i,c_list[i].y[1] if ( i > 0): print 'i-1= ',i-1,c_list[i-1].y[1] print 'len = ' , len(c_list) for i in range(5): print 'i= ',i,c_list[i].y[1] here is the output demonstrating that i am addressing the same memory: rsomervi...@galena:~/workspace/CSIRO_gui/trunk/src$ python test4.py len-a = 1 i= 0 0 i= 1 10 i-1= 0 10 i= 2 20 i-1= 1 20 i= 3 30 i-1= 2 30 i= 4 40 i-1= 3 40 len = 6 i= 0 40 i= 1 40 i= 2 40 i= 3 40 i= 4 40 -- http://mail.python.org/mailman/listinfo/python-list
How to test whether bit is set within a flag with Python ?
I am trying to determine how to test whether variors bits are set within a byte (or larger flag) , the python 'and' and 'or' do not seem to be doing what i want .. does anybody have some sample code showing how to do it ?? e.g. (in "C") unsigned char a = 6; is 3rd bit set ?? a & 4 =, true in this case thanks Robert Somerville -- http://mail.python.org/mailman/listinfo/python-list
Best XML python package to learn for Ubuntu Linux ?
Hi; I am about to get my feet wet with Python XML, there appears to be many libraries ... can someone recommend a good package to use on Ubuntu ??? regards; Robert Somerville -- http://mail.python.org/mailman/listinfo/python-list
re ElemenTree producing and reading examples needed :
does anybody have some working code that they can point me to so i could see ElemenTtree in action (especially writing XML files) ??? Thanks Robert Somerville -- http://mail.python.org/mailman/listinfo/python-list
ElementTree write creates large one line XML file ....
Hi I am using Ubuntu 9.10 and Python 2.6.4 .. when I create an ElementTree object and the write it out using: xml.etree.ElementTree.write() , I get one single long single line files, instead of something that looks reasonable , what gives ??? (and is it important ??) eg: I get : OneTwo instead of : One Two i found this example at: ( Listing 4 ) http://www.learningpython.com/2008/05/07/elegant-xml-parsing-using-the-elementtree-module/#Listing1 -- http://mail.python.org/mailman/listinfo/python-list
Re: ElementTree write creates large one line XML file ....
Thanks Robert Kern : "prettyprint" ; indent() does the trick ;-) >ElementTree writes exactly what you tell it to. In XML, whitespace is >significant. If you want newlines and/or indentation to make it pretty-looking, >then you need to add those to your elements. > >Fredrik provides an example function for doing this: > > http://effbot.org/zone/element-lib.htm#prettyprint -- http://mail.python.org/mailman/listinfo/python-list
python and filter design: calculating "s" optimal transform
Hi; this is an airy question. does anybody have some code or ideas on how to calculate the optimal "S" transform of user specified order (wanting the coefficients) for a published filter response curve, ie. f(s) = 1.0/(a1*S^2 + a2*S + a3) -- http://mail.python.org/mailman/listinfo/python-list
