2013/8/27 Anthony Scopatz <scop...@gmail.com>

>
> You are right that this loads the entire computed array into memory and is
> therefore not optimal.  I would do something like the following:
>
> h = tb.open_file(path, mode="a")
> varTable = h.get_node("/", var_name)
> coef = 3 * 60 * 60 #output step
> c = varTable.cols.field
> expr = tb.Expr("c * m", uservars = {"c": c, "m": coef })
> expr.set_output(c)
> expr.eval()
> varTable.flush()
> h.close()
>

Aha, this is cool. Thanks Anthony.

Cheers
--
Sasha


>
>>>  On Tue, Aug 27, 2013 at 11:44 AM, Oleksandr Huziy <
>>> guziy.sa...@gmail.com> wrote:
>>>
>>>>  Hi All:
>>>>
>>>> I have a huge table imported from other binary files to hdf, and I
>>>> forgot to multiply the data by a factor in one case. Is there an easy way
>>>> to multiply a column by a constant factor using pytables?
>>>> To modify it in place?
>>>>
>>>> Thank you
>>>>
>>>> --
>>>> Sasha
>>>>
>>>>
>>>> ------------------------------------------------------------------------------
>>>> Learn the latest--Visual Studio 2012, SharePoint 2013, SQL 2012, more!
>>>> Discover the easy way to master current and previous Microsoft
>>>> technologies
>>>> and advance your career. Get an incredible 1,500+ hours of step-by-step
>>>> tutorial videos with LearnDevNow. Subscribe today and save!
>>>>
>>>> http://pubads.g.doubleclick.net/gampad/clk?id=58040911&iu=/4140/ostg.clktrk
>>>> _______________________________________________
>>>> Pytables-users mailing list
>>>> Pytables-users@lists.sourceforge.net
>>>> https://lists.sourceforge.net/lists/listinfo/pytables-users
>>>>
>>>>
>>>
>>>
>>> ------------------------------------------------------------------------------
>>> Learn the latest--Visual Studio 2012, SharePoint 2013, SQL 2012, more!
>>> Discover the easy way to master current and previous Microsoft
>>> technologies
>>> and advance your career. Get an incredible 1,500+ hours of step-by-step
>>> tutorial videos with LearnDevNow. Subscribe today and save!
>>>
>>> http://pubads.g.doubleclick.net/gampad/clk?id=58040911&iu=/4140/ostg.clktrk
>>> _______________________________________________
>>> Pytables-users mailing list
>>> Pytables-users@lists.sourceforge.net
>>> https://lists.sourceforge.net/lists/listinfo/pytables-users
>>>
>>>
>>
>>
>> ------------------------------------------------------------------------------
>> Learn the latest--Visual Studio 2012, SharePoint 2013, SQL 2012, more!
>> Discover the easy way to master current and previous Microsoft
>> technologies
>> and advance your career. Get an incredible 1,500+ hours of step-by-step
>> tutorial videos with LearnDevNow. Subscribe today and save!
>>
>> http://pubads.g.doubleclick.net/gampad/clk?id=58040911&iu=/4140/ostg.clktrk
>> _______________________________________________
>> Pytables-users mailing list
>> Pytables-users@lists.sourceforge.net
>> https://lists.sourceforge.net/lists/listinfo/pytables-users
>>
>>
>
>
> ------------------------------------------------------------------------------
> Learn the latest--Visual Studio 2012, SharePoint 2013, SQL 2012, more!
> Discover the easy way to master current and previous Microsoft technologies
> and advance your career. Get an incredible 1,500+ hours of step-by-step
> tutorial videos with LearnDevNow. Subscribe today and save!
> http://pubads.g.doubleclick.net/gampad/clk?id=58040911&iu=/4140/ostg.clktrk
> _______________________________________________
> Pytables-users mailing list
> Pytables-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/pytables-users
>
>
------------------------------------------------------------------------------
Learn the latest--Visual Studio 2012, SharePoint 2013, SQL 2012, more!
Discover the easy way to master current and previous Microsoft technologies
and advance your career. Get an incredible 1,500+ hours of step-by-step
tutorial videos with LearnDevNow. Subscribe today and save!
http://pubads.g.doubleclick.net/gampad/clk?id=58040911&iu=/4140/ostg.clktrk
_______________________________________________
Pytables-users mailing list
Pytables-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/pytables-users

Reply via email to