mailRe: Speed up suggestion for task #7807.


Others Months | Index by Date | Thread Index
>>   [Date Prev] [Date Next] [Thread Prev] [Thread Next]

Header


Content

Posted by Troels Emtekær Linnet on June 11, 2014 - 11:56:
Hi Edward.

Some timings.
Per spin, you have a faster method.
But I win per cluster.

1000 iterations
1 / 100 spins

Edward
   ncalls  tottime  percall  cumtime  percall filename:lineno(function)
        1    0.000    0.000    0.523    0.523 <string>:1(<module>)
   ncalls  tottime  percall  cumtime  percall filename:lineno(function)
        1    0.000    0.000    3.875    3.875 <string>:1(<module>)

Troels Tile
   ncalls  tottime  percall  cumtime  percall filename:lineno(function)
        1    0.000    0.000    0.563    0.563 <string>:1(<module>)
   ncalls  tottime  percall  cumtime  percall filename:lineno(function)
        1    0.000    0.000    2.102    2.102 <string>:1(<module>)

Troels Outer
   ncalls  tottime  percall  cumtime  percall filename:lineno(function)
        1    0.000    0.000    0.546    0.546 <string>:1(<module>)
   ncalls  tottime  percall  cumtime  percall filename:lineno(function)
        1    0.000    0.000    1.974    1.974 <string>:1(<module>)

2014-06-11 11:46 GMT+02:00 Troels Emtekær Linnet <tlinnet@xxxxxxxxxxxxx>:
Hi Edward.

This is a really god page!
http://docs.scipy.org/doc/numpy/reference/ufuncs.html

""
Tip
The optional output arguments can be used to help you save memory for
large calculations. If your arrays are large, complicated expressions
can take longer than absolutely necessary due to the creation and
(later) destruction of temporary calculation spaces. For example, the
expression G = a * b + c is equivalent to t1 = A * B; G = T1 + C; del
t1. It will be more quickly executed as G = A * B; add(G, C, G) which
is the same as G = A * B; G += C.
""

2014-06-10 23:08 GMT+02:00 Edward d'Auvergne <edward@xxxxxxxxxxxxx>:
Note that masks and numpy.ma.multiply() and numpy.ma.add() may speed
this up even more.  However due to overheads in the numpy masking,
there is a chance that this also makes the dw and R20 data structure
construction slower.

Regards,

Edward



On 10 June 2014 22:36, Edward d'Auvergne <edward@xxxxxxxxxxxxx> wrote:
Hi Troels,

To make things even simpler, here is what needs to be done for R20,
R20A and R20B:

"""
from numpy import abs, add, array, float64, multiply, ones, sum, zeros

# Init mimic.
#############

# Values from Relax_disp.test_cpmg_synthetic_ns3d_to_cr72_noise_cluster.
NE = 1
NS = 2
NM = 2
NO = 1
ND = 8
R20A = array([  9.984626320294867,  11.495327724693091,
12.991028416082928, 14.498419290021163])
shape = (NE, NS, NM, NO, ND)

# Final structure for lib.dispersion.
R20A_struct = zeros(shape, float64)

# Temporary storage to avoid memory allocations and garbage collection.
R20A_temp = zeros(shape, float64)

# The structure for multiplication with R20A to piecewise build up the
full R20A structure.
R20A_mask = zeros((NS*NM,) + shape, float64)
for si in range(NS):
    for mi in range(NM):
        R20A_mask[si*NM+mi, :, si, mi] = 1.0
print(R20A_mask)
print("\n\n")

# Values to be found (again taken directly from
Relax_disp.test_cpmg_synthetic_ns3d_to_cr72_noise_cluster - as a
printout of dw_frq_a).
R20A_final = array([[[[[  9.984626320294867,   9.984626320294867,
9.984626320294867,
                          9.984626320294867,   9.984626320294867,
9.984626320294867,
                          9.984626320294867,   9.984626320294867]],

                      [[ 11.495327724693091,  11.495327724693091,
11.495327724693091,
                         11.495327724693091,  11.495327724693091,
11.495327724693091,
                         11.495327724693091,  11.495327724693091]]],


                     [[[ 12.991028416082928,  12.991028416082928,
12.991028416082928,
                         12.991028416082928,  12.991028416082928,
12.991028416082928,
                         12.991028416082928,  12.991028416082928]],

                      [[ 14.498419290021163,  14.498419290021163,
14.498419290021163,
                         14.498419290021163,  14.498419290021163,
14.498419290021163,
                         14.498419290021163,  14.498419290021163]]]]])


# Target function.
##################

# Loop over the R20A elements (one per spin).
for r20_index in range(NS*NM):
    # First multiply the spin specific R20A with the spin specific
frequency mask, using temporary storage.
    multiply(R20A[r20_index], R20A_mask[r20_index], R20A_temp)

    # The add to the total.
    add(R20A_struct, R20A_temp, R20A_struct)

# Show that the structure is reproduced perfectly.
print(R20A_struct)
print(R20A_struct - R20A_final)
print(sum(abs(R20A_struct - R20A_final)))
"""


You may notice one simplification compared to my previous example for
the dw parameter
(http://thread.gmane.org/gmane.science.nmr.relax.devel/6135/focus=6154).
The values here too come from the
Relax_disp.test_cpmg_synthetic_ns3d_to_cr72_noise_cluster system test.

Regards,

Edward


On 10 June 2014 21:31, Edward d'Auvergne <edward@xxxxxxxxxxxxx> wrote:
Hi Troels,

No need for an example.  Here is the code to add to your
infrastructure which will make the analytic dispersion models insanely
fast:


"""
from numpy import add, array, float64, multiply, ones, zeros

# Init mimic.
#############

# Values from Relax_disp.test_cpmg_synthetic_ns3d_to_cr72_noise_cluster.
NE = 1
NS = 2
NM = 2
NO = 1
ND = 8
dw = array([ 1.847792726895652,  0.193719379085542])
frqs = [-382.188861036982701, -318.479128911056137]
shape = (NE, NS, NM, NO, ND)

# Final structure for lib.dispersion.
dw_struct = zeros(shape, float64)

# Temporary storage to avoid memory allocations and garbage collection.
dw_temp = zeros((NS,) + shape, float64)

# The structure for multiplication with dw to piecewise build up the
full dw structure.
dw_mask = zeros((NS,) + shape, float64)
for si in range(NS):
    for mi in range(NM):
        dw_mask[si, :, si, mi] = frqs[mi]
print(dw_mask)

# Values to be found (again taken directly from
Relax_disp.test_cpmg_synthetic_ns3d_to_cr72_noise_cluster - as a
printout of dw_frq_a).
dw_final = array([[[[[-706.205797724669765, -706.205797724669765,
                      -706.205797724669765, -706.205797724669765,
                      -706.205797724669765, -706.205797724669765,
                      -706.205797724669765, -706.205797724669765]],

                    [[-588.483418069912318, -588.483418069912318,
                      -588.483418069912318, -588.483418069912318,
                      -588.483418069912318, -588.483418069912318,
                      -588.483418069912318, -588.483418069912318]]],


                   [[[ -74.03738885349469 ,  -74.03738885349469 ,
                       -74.03738885349469 ,  -74.03738885349469 ,
                       -74.03738885349469 ,  -74.03738885349469 ,
                       -74.03738885349469 ,  -74.03738885349469 ]],

                    [[ -61.69557910435401 ,  -61.69557910435401 ,
                       -61.69557910435401 ,  -61.69557910435401 ,
                       -61.69557910435401 ,  -61.69557910435401 ,
                       -61.69557910435401 ,  -61.69557910435401 ]]]]])


# Target function.
##################

# Loop over the dw elements (one per spin).
for si in range(NS):
    # First multiply the spin specific dw with the spin specific
frequency mask, using temporary storage.
    multiply(dw[si], dw_mask[si], dw_temp[si])

    # The add to the total.
    add(dw_struct, dw_temp[si], dw_struct)

# Show that the structure is reproduced perfectly.
print(dw_struct - dw_final)
"""

As mentioned in the comments, the structures come from the
Relax_disp.test_cpmg_synthetic_ns3d_to_cr72_noise_cluster.  I just
added a check of "if len(dw) > 1: asdfasd" to kill the test, and added
printouts to obtain dw, frq_a, dw_frq_a, etc.  This is exactly the
implementation I described.  Although there might be an even faster
way, this will eliminate all numpy array creation and deletion via
Python garbage collection in the target functions (when used for R20
as well).

Regards,

Edward

On 10 June 2014 21:09, Edward d'Auvergne <edward@xxxxxxxxxxxxx> wrote:
If you have a really complicated example of your current 'dw_frq_a'
data structure for multiple spins and multiple fields, that could help
to construct an example.

Cheers,

Edward



On 10 June 2014 20:57, Edward d'Auvergne <edward@xxxxxxxxxxxxx> wrote:
Hi,

I'll have a look tomorrow but, as you've probably seen, some of the
fine details such as indices to be used need to be sorted out when
implementing this.

Regards,

Edward


On 10 June 2014 20:49, Troels Emtekær Linnet <tlinnet@xxxxxxxxxxxxx> 
wrote:
What ever I do, I cannot get this to work?

Can you show an example ?

2014-06-10 16:29 GMT+02:00 Edward d'Auvergne <edward@xxxxxxxxxxxxx>:
Here is an example of avoiding automatic numpy data structure 
creation
and then garbage collection:

"""
from numpy import add, ones, zeros

a = zeros((5, 4))
a[1] = 1
a[:,1] = 2

b = ones((5, 4))

add(a, b, a)
print(a)
"""

The result is:

[[ 1.  3.  1.  1.]
 [ 2.  3.  2.  2.]
 [ 1.  3.  1.  1.]
 [ 1.  3.  1.  1.]
 [ 1.  3.  1.  1.]]

The out argument for numpy.add() is used here to operate in a similar
way to the Python "+=" operation.  But it avoids the temporary numpy
data structures that the Python "+=" operation will create.  This 
will
save a lot of time in the dispersion code.

Regards,

Edward


On 10 June 2014 15:56, Edward d'Auvergne <edward@xxxxxxxxxxxxx> 
wrote:
Hi Troels,

Here is one suggestion, of many that I have, for significantly
improving the speed of the analytic dispersion models in your
'disp_spin_speed' branch.  The speed ups you have currently achieved
for spin clusters are huge and very impressive.  But now that you 
have
the infrastructure in place, you can advance this much more!

The suggestion has to do with the R20, R20A, and R20B numpy data
structures.  They way they are currently handled is relatively
inefficient, in that they are created de novo for each function 
call.
This means that memory allocation and Python garbage collection
happens for every single function call - something which should be
avoided at almost all costs.

A better way to do this would be to have a self.R20_struct,
self.R20A_struct, and self.R20B_struct created in __init__(), and 
then
to pack in the values from the parameter vector into these 
structures.
You could create a special structure in __init__() for this.  It 
would
have the dimensions [r20_index][ei][si][mi][oi], where the first
dimension corresponds to the different R20 parameters.  And for each
r20_index element, you would have ones at the [ei][si][mi][oi]
positions where you would like R20 to be, and zeros elsewhere.  The
key is that this is created at the target function start up, and not
for each function call.

This would be combined with the very powerful 'out' argument set to
self.R20_struct with the numpy.add() and numpy.multiply() functions 
to
prevent all memory allocations and garbage collection.  Masks could 
be
used, but I think that that would be much slower than having special
numpy structures with ones where R20 should be and zeros elsewhere.
For just creating these structures, looping over a single r20_index
loop and multiplying by the special [r20_index][ei][si][mi][oi]
one/zero structure and using numpy.add() and numpy.multiply() with 
out
arguments would be much, much faster than masks or the current
R20_axis logic.  It will also simplify the code.

Regards,

Edward

_______________________________________________
relax (http://www.nmr-relax.com)

This is the relax-devel mailing list
relax-devel@xxxxxxx

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



Related Messages


Powered by MHonArc, Updated Wed Jun 11 12:20:11 2014