Re: [Numpy-discussion] non-uniform discrete sampling with given probabilities (w/ and w/o replacement)

2011-08-31 Thread Christopher Jordan-Squire
On Wed, Aug 31, 2011 at 3:34 PM, wrote: > On Wed, Aug 31, 2011 at 3:22 PM, Olivier Delalleau wrote: >> 2011/8/31 Christopher Jordan-Squire >>> >>> On Wed, Aug 31, 2011 at 2:07 PM, Olivier Delalleau wrote: >>> > You can use: >>> > 1 + numpy.argmax(numpy.random.multinomial(1, [0.1, 0.2, 0.7])) >

Re: [Numpy-discussion] non-uniform discrete sampling with given probabilities (w/ and w/o replacement)

2011-08-31 Thread josef . pktd
On Wed, Aug 31, 2011 at 3:22 PM, Olivier Delalleau wrote: > 2011/8/31 Christopher Jordan-Squire >> >> On Wed, Aug 31, 2011 at 2:07 PM, Olivier Delalleau wrote: >> > You can use: >> > 1 + numpy.argmax(numpy.random.multinomial(1, [0.1, 0.2, 0.7])) >> > >> > For your "real" application you'll proba

Re: [Numpy-discussion] non-uniform discrete sampling with given probabilities (w/ and w/o replacement)

2011-08-31 Thread Olivier Delalleau
2011/8/31 Christopher Jordan-Squire > On Wed, Aug 31, 2011 at 2:07 PM, Olivier Delalleau wrote: > > You can use: > > 1 + numpy.argmax(numpy.random.multinomial(1, [0.1, 0.2, 0.7])) > > > > For your "real" application you'll probably want to use a value >1 for > the > > first parameter (equal to y

Re: [Numpy-discussion] non-uniform discrete sampling with given probabilities (w/ and w/o replacement)

2011-08-31 Thread Christopher Jordan-Squire
On Wed, Aug 31, 2011 at 2:07 PM, Olivier Delalleau wrote: > You can use: > 1 + numpy.argmax(numpy.random.multinomial(1, [0.1, 0.2, 0.7])) > > For your "real" application you'll probably want to use a value >1 for the > first parameter (equal to your sample size), instead of calling it multiple > t

Re: [Numpy-discussion] non-uniform discrete sampling with given probabilities (w/ and w/o replacement)

2011-08-31 Thread Olivier Delalleau
You can use: 1 + numpy.argmax(numpy.random.multinomial(1, [0.1, 0.2, 0.7])) For your "real" application you'll probably want to use a value >1 for the first parameter (equal to your sample size), instead of calling it multiple times. -=- Olivier 2011/8/31 Christopher Jordan-Squire > In numpy,

[Numpy-discussion] non-uniform discrete sampling with given probabilities (w/ and w/o replacement)

2011-08-31 Thread Christopher Jordan-Squire
In numpy, is there a way of generating a random integer in a specified range where the integers in that range have given probabilities? So, for example, generating a random integer between 1 and 3 with probabilities [0.1, 0.2, 0.7] for the three integers? I'd like to know how to do this without re

Re: [Numpy-discussion] Question on LinAlg Inverse Algorithm

2011-08-31 Thread Mark Janikas
When I say garbage, I mean in the context of my hypothesis testing when in the presence of perfect multicollinearity. I advise the user of the combination that leads to the problem and move on -Original Message- From: numpy-discussion-boun...@scipy.org [mailto:numpy-discussion-bou

Re: [Numpy-discussion] Question on LinAlg Inverse Algorithm

2011-08-31 Thread Bruce Southey
On 08/31/2011 12:56 PM, Mark Janikas wrote: > Right indeed... I have spent a lot of time looking at this and it seems a > waste of time as the results are garbage anyways when the columns are > collinear. I am just going to set a threshold, check the condition number, > continue is satisfied, r

Re: [Numpy-discussion] Question on LinAlg Inverse Algorithm

2011-08-31 Thread Mark Janikas
Right indeed... I have spent a lot of time looking at this and it seems a waste of time as the results are garbage anyways when the columns are collinear. I am just going to set a threshold, check the condition number, continue is satisfied, return error/warning if not now, what is too larg

Re: [Numpy-discussion] Numpy performance boost

2011-08-31 Thread Isaac Gouy
- Original Message - > From: Chris.Barker > To: numpy-discussion@scipy.org > Cc: > Sent: Wednesday, August 31, 2011 9:08 AM > Subject: Re: [Numpy-discussion] Numpy performance boost > > On 8/31/11 3:58 AM, Dieter Weber wrote: >>  just wanted to show an example of how python3 + numpy comp

Re: [Numpy-discussion] Numpy performance boost

2011-08-31 Thread Chris.Barker
On 8/31/11 3:58 AM, Dieter Weber wrote: > just wanted to show an example of how python3 + numpy compares with just > python3 and many other languages and language implementations: > http://shootout.alioth.debian.org/u64q/performance.php?test=mandelbrot#about hmmm - it would be interesting to see w

Re: [Numpy-discussion] Numpy performance boost

2011-08-31 Thread Isaac Gouy
Dieter, thank you for contributing a numpy mandelbrot program - but no thanks for your "disqualified for doing things differently" comment here. The benchmarks game has been showing a spectral-norm program based on numpy as an "interesting alternative" for the last couple of years - http://shoot

Re: [Numpy-discussion] A question about dtype syntax

2011-08-31 Thread Warren Weckesser
On Wed, Aug 31, 2011 at 9:24 AM, Jean-Baptiste Marquette wrote: > > Hi Pierre, > > > On Aug 31, 2011, at 3:40 PM, Jean-Baptiste Marquette wrote: > > Traceback (most recent call last): > > File "/Users/marquett/workspace/Distort/src/StatsSep.py", line 44, in > > >np.savetxt(Table, StatsAll, d

Re: [Numpy-discussion] A question about dtype syntax

2011-08-31 Thread Pierre GM
On Aug 31, 2011, at 4:24 PM, Jean-Baptiste Marquette wrote: > > Hi Pierre, > >> >> On Aug 31, 2011, at 3:40 PM, Jean-Baptiste Marquette wrote: >>> Traceback (most recent call last): >>> File "/Users/marquett/workspace/Distort/src/StatsSep.py", line 44, in >>> >>>np.savetxt(Table, StatsA

Re: [Numpy-discussion] A question about dtype syntax

2011-08-31 Thread Jean-Baptiste Marquette
Hi Pierre, > > On Aug 31, 2011, at 3:40 PM, Jean-Baptiste Marquette wrote: >> Traceback (most recent call last): >> File "/Users/marquett/workspace/Distort/src/StatsSep.py", line 44, in >> >>np.savetxt(Table, StatsAll, delimiter=' ', fmt=['%15s %.5f %.5f %5d %.4f >> %.4f']) >> File >>

Re: [Numpy-discussion] A question about dtype syntax

2011-08-31 Thread Pierre GM
On Aug 31, 2011, at 3:40 PM, Jean-Baptiste Marquette wrote: > Traceback (most recent call last): > File "/Users/marquett/workspace/Distort/src/StatsSep.py", line 44, in > > np.savetxt(Table, StatsAll, delimiter=' ', fmt=['%15s %.5f %.5f %5d %.4f > %.4f']) > File > "/Library/Frameworks/

Re: [Numpy-discussion] A question about dtype syntax

2011-08-31 Thread Jean-Baptiste Marquette
Hi Pierre, Bingo ! That works. I finally coded like: Stats = [(CatBase, round(stats.mean(Data.Ra), 5), round(stats.mean(Data.Dec), 5), len(Sep), round(stats.mean(Sep),4), round(stats.stdev(Sep),4),)] StatArray = np.array(Stats, dtype=([('Catalog', 'a15'), ('RaMean', 'f

[Numpy-discussion] Model Predictive Control package

2011-08-31 Thread Davide
Dear List, Does anybody knows if there is a python package for simulating LTI dynamic systems controlled with a model predictive controller? I am writing some code which does the job, but the math is not super-easy and i would not like to reinvent the wheel and loose to much time. I will soon

[Numpy-discussion] Numpy performance boost

2011-08-31 Thread Dieter Weber
Hi, just wanted to show an example of how python3 + numpy compares with just python3 and many other languages and language implementations: http://shootout.alioth.debian.org/u64q/performance.php?test=mandelbrot#about The python3 program using numpy is #6 and you find it with the "interesting alter

Re: [Numpy-discussion] A question about dtype syntax

2011-08-31 Thread Pierre GM
On Aug 31, 2011, at 12:20 PM, Jean-Baptiste Marquette wrote: > > Hi Pierre, > > Thanks for the guess. Unfortunately, I got the same error: > > [('bs3000k.cat', 280.60341, -7.09118, 9480, 0.2057, 0.14)] > Traceback (most recent call last): > File "/Users/marquett/workspace/Distort/src/StatsSe

Re: [Numpy-discussion] A question about dtype syntax

2011-08-31 Thread Jean-Baptiste Marquette
Hi Pierre, Thanks for the guess. Unfortunately, I got the same error: [('bs3000k.cat', 280.60341, -7.09118, 9480, 0.2057, 0.14)] Traceback (most recent call last): File "/Users/marquett/workspace/Distort/src/StatsSep.py", line 40, in StatsAll = np.array(np.asarray(Stats), dtype=('a15, f8,

Re: [Numpy-discussion] Question on LinAlg Inverse Algorithm

2011-08-31 Thread Pauli Virtanen
On Tue, 30 Aug 2011 15:48:18 -0700, Mark Janikas wrote: > Last week I posted a question involving the identification of linear > dependent columns of a matrix... but now I am finding an interesting > result based on the linalg.inv() function... sometime I am able to > invert a matrix that has linea