That might work - but it will require testing.  I really don't know
what will happen.  The current test suite should be sufficient for the
testing.  Also, keep the returning of the data structure for the
branch!

Regards,

Edward

On 9 May 2014 16:04, Troels Emtekær Linnet <[email protected]> wrote:
> Would you agree on discarding the whole loop, return one array with
> all values = 1e100,
> rather than some elements have 1e100, but other rather high values.?
>
> Best
> Troels
>
> 2014-05-09 15:58 GMT+02:00 Edward d'Auvergne <[email protected]>:
>> Hi,
>>
>> To set up a branch, just read the 3 small sections of the 'Branches'
>> section of the user manual
>> (http://www.nmr-relax.com/manual/Branches.html).  Using git here is
>> fatal.  But all the commands you need are listed there.  Try the CR72
>> optimisations first though.  Those will then make the API changes much
>> easier.
>>
>> Regards,
>>
>> Edward
>>
>>
>>
>> On 9 May 2014 15:34, Troels Emtekær Linnet <[email protected]> wrote:
>>> How do I setup a branch? :-)
>>>
>>> Best
>>> Troels
>>>
>>> 2014-05-09 15:31 GMT+02:00 Troels Emtekær Linnet <[email protected]>:
>>>> Hi Edward.
>>>>
>>>> I really think for my case, that 25 speed up is a deal breaker !
>>>> I have so much data to crunch, that 25 speed is absolutely perfect.
>>>>
>>>> I would only optimise this for CR72, and TSMFK01, since these are the
>>>> ones I need now.
>>>> And the change of code is only 3-5 lines?
>>>>
>>>> And i was thinking of one thing more.
>>>>
>>>> CR72 always go over loop.
>>>>
>>>> -----------
>>>>     # Loop over the time points, back calculating the R2eff values.
>>>>     for i in range(num_points):
>>>>         # The full eta+/- values.
>>>>         etapos = etapos_part / cpmg_frqs[i]
>>>>         etaneg = etaneg_part / cpmg_frqs[i]
>>>>
>>>>         # Catch large values of etapos going into the cosh function.
>>>>         if etapos > 100:
>>>>             back_calc[i] = 1e100
>>>>             continue
>>>>
>>>>         # The arccosh argument - catch invalid values.
>>>>         fact = Dpos * cosh(etapos) - Dneg * cos(etaneg)
>>>>         if fact < 1.0:
>>>>             back_calc[i] = r20_kex
>>>>             continue
>>>>
>>>>         # The full formula.
>>>>         back_calc[i] = r20_kex - cpmg_frqs[i] * arccosh(fact)
>>>> ------------
>>>> I would rather do:
>>>> etapos = etapos_part / cpmg_frqs
>>>>
>>>> And then check for nan values.
>>>> If any of these are there, just return the whole array with 1e100,
>>>> instead of single values.
>>>> That would replace a loop with a check.
>>>>
>>>> Best
>>>> Troels
>>>>
>>>>
>>>> 2014-05-09 14:58 GMT+02:00 Edward d'Auvergne <[email protected]>:
>>>>> Hi,
>>>>>
>>>>> This approach can add a little speed.  You really need to stress test
>>>>> and have profile timings to understand.  You should also try different
>>>>> Python versions (2 and 3) because each implementation is different.
>>>>> You can sometimes have a speed up in Python 2 which does nothing in
>>>>> Python 3 (due to Python 3 being more optimised).  There can also be
>>>>> huge differences between numpy versions.  Anyway, here is a powerful
>>>>> test which shows 3 different implementation ideas for the
>>>>> back-calculated R2eff data in the dispersion functions:
>>>>>
>>>>> """
>>>>> import cProfile as profile
>>>>> from numpy import array, cos, float64, sin, zeros
>>>>> import pstats
>>>>>
>>>>> def in_place(values, bc):
>>>>>     x = cos(values) * sin(values)
>>>>>     for i in range(len(bc)):
>>>>>         bc[i] = x[i]
>>>>>
>>>>> def really_slow(values, bc):
>>>>>     for i in range(len(bc)):
>>>>>         x = cos(values[i]) * sin(values[i])
>>>>>         bc[i] = x
>>>>>
>>>>> def return_bc(values):
>>>>>     return cos(values) * sin(values)
>>>>>
>>>>> def test_in_place(inc=None, values=None, values2=None, bc=None):
>>>>>     for i in range(inc):
>>>>>         in_place(values, bc[0])
>>>>>         in_place(values2, bc[1])
>>>>>     print(bc)
>>>>>
>>>>> def test_really_slow(inc=None, values=None, values2=None, bc=None):
>>>>>     for i in range(inc):
>>>>>         really_slow(values, bc[0])
>>>>>         really_slow(values2, bc[1])
>>>>>     print(bc)
>>>>>
>>>>> def test_return_bc(inc=None, values=None, values2=None, bc=None):
>>>>>     for i in range(inc):
>>>>>         bc[0] = return_bc(values)
>>>>>         bc[1] = return_bc(values2)
>>>>>     print(bc)
>>>>>
>>>>> def test():
>>>>>     values = array([1, 3, 0.1], float64)
>>>>>     values2 = array([0.1, 0.2, 0.3], float64)
>>>>>     bc = zeros((2, 3), float64)
>>>>>     inc = 1000000
>>>>>     test_in_place(inc=inc, values=values, values2=values2, bc=bc)
>>>>>     test_really_slow(inc=inc, values=values, values2=values2, bc=bc)
>>>>>     test_return_bc(inc=inc, values=values, values2=values2, bc=bc)
>>>>>
>>>>> def print_stats(stats, status=0):
>>>>>     pstats.Stats(stats).sort_stats('time', 'name').print_stats()
>>>>> profile.Profile.print_stats = print_stats
>>>>> profile.runctx('test()', globals(), locals())
>>>>> """"
>>>>>
>>>>>
>>>>> Try running this in Python 2 and 3.  If the cProfile import does not
>>>>> work on one version, try simply "import profile".  You should create
>>>>> such scripts for testing out code optimisation ideas.  Knowing how to
>>>>> profile is essential.  For Python 3, I see:
>>>>>
>>>>> """
>>>>> $ python3.4 edward.py
>>>>> [[ 0.45464871 -0.13970775  0.09933467]
>>>>>  [ 0.09933467  0.19470917  0.28232124]]
>>>>> [[ 0.45464871 -0.13970775  0.09933467]
>>>>>  [ 0.09933467  0.19470917  0.28232124]]
>>>>> [[ 0.45464871 -0.13970775  0.09933467]
>>>>>  [ 0.09933467  0.19470917  0.28232124]]
>>>>>          10001042 function calls (10001036 primitive calls) in 39.303 
>>>>> seconds
>>>>>
>>>>>    Ordered by: internal time, function name
>>>>>
>>>>>    ncalls  tottime  percall  cumtime  percall filename:lineno(function)
>>>>>   2000000   19.744    0.000   19.867    0.000 edward.py:10(really_slow)
>>>>>   2000000    9.128    0.000    9.286    0.000 edward.py:5(in_place)
>>>>>   2000000    5.966    0.000    5.966    0.000 edward.py:15(return_bc)
>>>>>         1    1.964    1.964    7.931    7.931 edward.py:30(test_return_bc)
>>>>>         1    1.119    1.119   20.987   20.987 
>>>>> edward.py:24(test_really_slow)
>>>>>         1    1.099    1.099   10.385   10.385 edward.py:18(test_in_place)
>>>>>   4000198    0.281    0.000    0.281    0.000 {built-in method len}
>>>>>        27    0.001    0.000    0.001    0.000 {method 'reduce' of
>>>>> 'numpy.ufunc' objects}
>>>>> """
>>>>>
>>>>> Here you can see that test_return_bc() is 80% the speed of
>>>>> test_in_place().  The 'cumtime' is the important number, this is the
>>>>> total amount of time spent in that function.  So the speed up is not
>>>>> huge.  For Python 2:
>>>>>
>>>>> """
>>>>> $ python2.7 edward.py
>>>>> [[ 0.45464871 -0.13970775  0.09933467]
>>>>>  [ 0.09933467  0.19470917  0.28232124]]
>>>>> [[ 0.45464871 -0.13970775  0.09933467]
>>>>>  [ 0.09933467  0.19470917  0.28232124]]
>>>>> [[ 0.45464871 -0.13970775  0.09933467]
>>>>>  [ 0.09933467  0.19470917  0.28232124]]
>>>>>          14000972 function calls (14000966 primitive calls) in 38.625 
>>>>> seconds
>>>>>
>>>>>    Ordered by: internal time, function name
>>>>>
>>>>>    ncalls  tottime  percall  cumtime  percall filename:lineno(function)
>>>>>   2000000   18.373    0.000   19.086    0.000 edward.py:10(really_slow)
>>>>>   2000000    8.798    0.000    9.576    0.000 edward.py:5(in_place)
>>>>>   2000000    5.937    0.000    5.937    0.000 edward.py:15(return_bc)
>>>>>         1    1.839    1.839    7.785    7.785 edward.py:30(test_return_bc)
>>>>>   4000021    1.141    0.000    1.141    0.000 {range}
>>>>>         1    1.086    1.086   10.675   10.675 edward.py:18(test_in_place)
>>>>>         1    1.070    1.070   20.165   20.165 
>>>>> edward.py:24(test_really_slow)
>>>>>   4000198    0.379    0.000    0.379    0.000 {len}
>>>>> """
>>>>>
>>>>> Hmmm, Python 2 is faster than Python 3 for this example!  See for
>>>>> yourself.  If you really think that making the code 1.25 times faster,
>>>>> as shown in these tests, is worth your time, then this must be done in
>>>>> a subversion branch (http://svn.gna.org/viewcvs/relax/branches/).
>>>>> That way we can have timing tests between the trunk and the branch.
>>>>> As this affects all dispersion models, the changes will be quite
>>>>> disruptive.  And if the implementation is not faster or if it breaks
>>>>> everything, then the branch can be deleted.  What ever you do, please
>>>>> don't use a git-svn branch.
>>>>>
>>>>> Regards,
>>>>>
>>>>> Edward
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> On 9 May 2014 14:07, Troels Emtekær Linnet <[email protected]> wrote:
>>>>>> Hi Edward.
>>>>>>
>>>>>> How about this script?
>>>>>> Here I try to pass the back the r2eff values, and then set them in the
>>>>>> back_calculated class object.
>>>>>> Will this work ??
>>>>>>
>>>>>> Or else I found this post about updating values.
>>>>>> http://stackoverflow.com/questions/14916284/in-python-class-object-how-to-auto-update-attributes
>>>>>> They talk about
>>>>>> @property
>>>>>> and setter, which I dont get yet. :-)
>>>>>>
>>>>>> Best
>>>>>> Troels
>>>>>>
>>>>>>
>>>>>> ---------------
>>>>>>
>>>>>>
>>>>>> def loop_rep(x, nr):
>>>>>>     y = [98, 99]
>>>>>>     for i in range(nr):
>>>>>>         x[i] = y[i]
>>>>>>
>>>>>> def not_loop_rep(x, nr):
>>>>>>     y = [98, 99]
>>>>>>     x = y
>>>>>>
>>>>>> def not_loop_rep_new(x, nr):
>>>>>>     y = [98, 99]
>>>>>>     x = y
>>>>>>     return x
>>>>>>
>>>>>>
>>>>>> class MyClass:
>>>>>>     def __init__(self, x):
>>>>>>         self.x = x
>>>>>>         self.nr = len(x)
>>>>>>
>>>>>>     def printc(self):
>>>>>>         print self.x, self.nr
>>>>>>
>>>>>>     def calc_loop_rep(self, x=None, nr=None):
>>>>>>         loop_rep(x=self.x, nr=self.nr)
>>>>>>
>>>>>>     def calc_not_loop_rep(self, x=None, nr=None):
>>>>>>         not_loop_rep(x=self.x, nr=self.nr)
>>>>>>
>>>>>>     def calc_not_loop_rep_new(self, x=None, nr=None):
>>>>>>         self.x = not_loop_rep_new(x=self.x, nr=self.nr)
>>>>>>
>>>>>> print("For class where we loop replace ")
>>>>>> "Create object of class"
>>>>>> t_rep = MyClass([0, 1])
>>>>>> "Print object of class"
>>>>>> t_rep.printc()
>>>>>> "Calc object of class"
>>>>>> t_rep.calc_loop_rep()
>>>>>> " Then print"
>>>>>> t_rep.printc()
>>>>>>
>>>>>> print("\nFor class where we not loop replace ")
>>>>>> " Now try with replace "
>>>>>> t = MyClass([3, 4])
>>>>>> t.printc()
>>>>>> t.calc_not_loop_rep()
>>>>>> t.printc()
>>>>>>
>>>>>> print("\nFor class where we not loop replace ")
>>>>>> t_new = MyClass([5, 6])
>>>>>> t_new.printc()
>>>>>> t_new.calc_not_loop_rep_new()
>>>>>> t_new.printc()
>>>>>>
>>>>>> 2014-05-05 19:07 GMT+02:00 Edward d'Auvergne <[email protected]>:
>>>>>>> :)  It does slow it down a little, but that's unavoidable.  It's also
>>>>>>> unavoidable in C, Fortran, Perl, etc.  As long as the number of
>>>>>>> operations in that loop is minimal, then it's the best you can do.  If
>>>>>>> it worries you, you could run a test where you call the target
>>>>>>> function say 1e6 times, with and without the loop to see the timing
>>>>>>> difference.  Or simply running in Python 2:
>>>>>>>
>>>>>>> for i in xrange(1000000):
>>>>>>>  x = 1
>>>>>>>
>>>>>>> Then try:
>>>>>>>
>>>>>>> for i in xrange(100000000):
>>>>>>>  x = 2
>>>>>>>
>>>>>>> These two demonstrate the slowness of the Python loop.  But the second
>>>>>>> case is extreme and you won't encounter that much looping in these
>>>>>>> functions.  So while it is theoretically slower than C and Fortran
>>>>>>> looping, you can probably see that no one would care :)  Here is
>>>>>>> another test, with Python 2 code:
>>>>>>>
>>>>>>> """
>>>>>>> import cProfile as profile
>>>>>>>
>>>>>>> def loop_1e6():
>>>>>>>     for i in xrange(int(1e6)):
>>>>>>>         x = 1
>>>>>>>
>>>>>>> def loop_1e8():
>>>>>>>     for i in xrange(int(1e8)):
>>>>>>>         x = 1
>>>>>>>
>>>>>>> def sum_conv():
>>>>>>>     for i in xrange(100000000):
>>>>>>>         x = 2 + 2.
>>>>>>>
>>>>>>> def sum_normal():
>>>>>>>     for i in xrange(100000000):
>>>>>>>         x = 2. + 2.
>>>>>>>
>>>>>>> def test():
>>>>>>>     loop_1e6()
>>>>>>>     loop_1e8()
>>>>>>>     sum_normal()
>>>>>>>     sum_conv()
>>>>>>>
>>>>>>> profile.runctx('test()', globals(), locals())
>>>>>>> """
>>>>>>>
>>>>>>> Running this on my system shows:
>>>>>>>
>>>>>>> """
>>>>>>>          7 function calls in 6.707 seconds
>>>>>>>
>>>>>>>    Ordered by: standard name
>>>>>>>
>>>>>>>    ncalls  tottime  percall  cumtime  percall filename:lineno(function)
>>>>>>>         1    0.000    0.000    6.707    6.707 <string>:1(<module>)
>>>>>>>         1    2.228    2.228    2.228    2.228 aaa.py:11(sum_conv)
>>>>>>>         1    2.228    2.228    2.228    2.228 aaa.py:15(sum_normal)
>>>>>>>         1    0.000    0.000    6.707    6.707 aaa.py:19(test)
>>>>>>>         1    0.022    0.022    0.022    0.022 aaa.py:3(loop_1e6)
>>>>>>>         1    2.228    2.228    2.228    2.228 aaa.py:7(loop_1e8)
>>>>>>>         1    0.000    0.000    0.000    0.000 {method 'disable' of
>>>>>>> '_lsprof.Profiler' objects}
>>>>>>> """
>>>>>>>
>>>>>>> That should be self explanatory.  The better optimisation targets are
>>>>>>> the repeated maths operations and the maths operations that can be
>>>>>>> shifted into the target function or the target function
>>>>>>> initialisation.  Despite the numbers above which prove my int to float
>>>>>>> speed argument as utter nonsense, it might still good to remove the
>>>>>>> int to float conversions, if only to match the other functions.
>>>>>>>
>>>>>>> Regards,
>>>>>>>
>>>>>>> Edward
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> On 5 May 2014 18:45, Troels Emtekær Linnet <[email protected]> 
>>>>>>> wrote:
>>>>>>>> The reason why I ask, is that I am afraid that this for loop slows
>>>>>>>> everything down.
>>>>>>>>
>>>>>>>> What do you think?
>>>>>>>>
>>>>>>>> 2014-05-05 18:41 GMT+02:00 Edward d'Auvergne <[email protected]>:
>>>>>>>>> This is not Python specific though :)  As far as I know, C uses
>>>>>>>>> pass-by-value for arguments, unless they are arrays or other funky
>>>>>>>>> objects/functions/etc..  This is the same behaviour as Python.
>>>>>>>>> Pass-by-reference and pass-by-value is something that needs to be
>>>>>>>>> mastered in all languages, whether or not you have pointers to play
>>>>>>>>> with.
>>>>>>>>>
>>>>>>>>> Regards,
>>>>>>>>>
>>>>>>>>> Edward
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> On 5 May 2014 18:30, Troels Emtekær Linnet <[email protected]> 
>>>>>>>>> wrote:
>>>>>>>>>> This reminds me:
>>>>>>>>>>
>>>>>>>>>> http://combichem.blogspot.dk/2013/08/you-know-what-really-grinds-my-gears-in.html
>>>>>>>>>>
>>>>>>>>>> 2014-05-05 17:52 GMT+02:00 Edward d'Auvergne <[email protected]>:
>>>>>>>>>>> Hi,
>>>>>>>>>>>
>>>>>>>>>>> This is an important difference.  In the first case (back_calc[i] =
>>>>>>>>>>> Minty[i]), what is happening is that your are copying the data into 
>>>>>>>>>>> a
>>>>>>>>>>> pre-existing structure.  In the second case (back_calc = Minty), the
>>>>>>>>>>> existing back_calc structure will be overwritten.  Therefore the
>>>>>>>>>>> back_calc structure in the calling code will be modified in the 
>>>>>>>>>>> first
>>>>>>>>>>> case but not the second.  Here is some demo code:
>>>>>>>>>>>
>>>>>>>>>>> def mod1(x):
>>>>>>>>>>>     x[0] = 1
>>>>>>>>>>>
>>>>>>>>>>> def mod2(x):
>>>>>>>>>>>     x = [3, 2]
>>>>>>>>>>>
>>>>>>>>>>> x = [0, 2]
>>>>>>>>>>> print(x)
>>>>>>>>>>> mod1(x)
>>>>>>>>>>> print(x)
>>>>>>>>>>> mod2(x)
>>>>>>>>>>> print(x)
>>>>>>>>>>>
>>>>>>>>>>> I don't know of a way around this.
>>>>>>>>>>>
>>>>>>>>>>> Regards,
>>>>>>>>>>>
>>>>>>>>>>> Edward
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> On 5 May 2014 17:42, Troels Emtekær Linnet <[email protected]> 
>>>>>>>>>>> wrote:
>>>>>>>>>>>> Hi Edward.
>>>>>>>>>>>>
>>>>>>>>>>>> In the library function of b14.py, i am looping over
>>>>>>>>>>>> the dispersion points to put in the data.
>>>>>>>>>>>>
>>>>>>>>>>>>     for i in range(num_points):
>>>>>>>>>>>>
>>>>>>>>>>>>         # The full formula.
>>>>>>>>>>>>         back_calc[i] = Minty[i]
>>>>>>>>>>>>
>>>>>>>>>>>> Why can I not just set:
>>>>>>>>>>>> back_calc = Minty
>>>>>>>>>>>>
>>>>>>>>>>>> _______________________________________________
>>>>>>>>>>>> relax (http://www.nmr-relax.com)
>>>>>>>>>>>>
>>>>>>>>>>>> This is the relax-devel mailing list
>>>>>>>>>>>> [email protected]
>>>>>>>>>>>>
>>>>>>>>>>>> To unsubscribe from this list, get a password
>>>>>>>>>>>> reminder, or change your subscription options,
>>>>>>>>>>>> visit the list information page at
>>>>>>>>>>>> https://mail.gna.org/listinfo/relax-devel

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