Rahul Iyer | 28 Mar 16:59 2015

Re: [MADlib-user] Random Forest classification

You could write the SQL for such a random classifier.
For eg. using the dt_golf dataset from decision tree example page
<http://doc.madlib.net/latest/group__grp__decision__tree.html#examples>, we
can produce random classes as:

SELECT class, classes[trunc(random()*2 + 1)] as random_class
FROM dt_golf,

(SELECT ARRAY['Play', 'Don''t Play'] as classes) q1;

In the query, the expression trunc(random()*2 + 1 computes a random integer
between 1 and 2. You would need to replace '2' with the number of classes
in your data.

- Rahul

On Fri, Mar 27, 2015 at 8:56 PM, <dpopova@...> wrote:

> Rahul,
> Sorry to bug you on the weekend. But does MADlib have a random classifier?
> Something that puts random values into the class variable, to establish a
> baseline for a particular dataset?
> For example, WEKA has ZeroR classifier.
> Thank you,
> Diana
> > Yes. That's the goal of tree_predict (signature below):
(Continue reading)

dpopova | 26 Mar 02:42 2015

[MADlib-user] Random Forest classification

Dear all,

I am trying to run forest_train function on a dataset. I have already
successfully trained this data using tree_train. But the forest_train
gives the following error message:
dianapopova=# \c maddb
You are now connected to database "maddb" as user "dianapopova".
maddb=# SELECT madlib.forest_train('madlib.pull_request_class_merged',
maddb(# 'forest_output',
maddb(# 'pull_req_id',
maddb(# 'merged',
maddb(# '*',
maddb(# NULL
maddb(# );
ERROR:  AttributeError: 'NoneType' object has no attribute 'strip'
CONTEXT:  Traceback (most recent call last):
  PL/Python function "forest_train", line 41, in <module>
  PL/Python function "forest_train", line 279, in forest_train
  PL/Python function "forest_train", line 1486, in _forest_validate_args
PL/Python function "forest_train"
Could you please advise?

Thank you,

AJ Welch | 3 Jan 08:31 2015

[MADlib-user] Distribute on pgxn?

Looks like madlib was distributed on pgxn at one point:


Why was 1.3 the last distribution? Not enough support to make it a priority?

Bryan Bickford | 11 Dec 20:01 2014

[MADlib-user] Concurrency Support

I was wondering what level of concurrency is supported in MADlib 1.6.

I have a multi user/multi database system. Since madpack installs on
seperate databases, I assume that there is concurrency support built in
across databases?

Can the same be said for multiple users simultaneously accessing the same
database with the same or different madlib function calls?

Gareth James | 9 Dec 21:46 2014

[MADlib-user] Redshift

Is the postgres version used at Amazon Redshift supported by madlib?
Ioannis Atsonios | 9 Sep 11:12 2014

Re: [MADlib-user] Welcome to the "User" mailing list


On Tue, Sep 9, 2014 at 12:20 PM, <user-request@...> wrote:

> Welcome to the User@... mailing list!
> To post to this list, send your email to:
>   user@...
> General information about the mailing list is at:
>   http://madlib.net/mailman/listinfo/user
> If you ever want to unsubscribe or change your options (eg, switch to
> or from digest mode, change your password, etc.), visit your
> subscription page at:
>   http://madlib.net/mailman/options/user/iatsonios%40gmail.com
> You can also make such adjustments via email by sending a message to:
>   User-request@...
> with the word `help' in the subject or body (don't include the
> quotes), and you will get back a message with instructions.
> You must know your password to change your options (including changing
> the password, itself) or to unsubscribe.  It is:
(Continue reading)

afancy | 7 Sep 19:29 2014

[MADlib-user] compile error on MADlib 1.6 + PostgreSQL9.3


I compile Madlib1.6 againt postgresql 9.3 on Ubuntu 12.04. But there is an
It would be apprecaiated if anybody could help . Thanks


root <at> xiliu-ubuntu:/tmp/madlib-1.6.0# make
make -C build all
make[1]: Entering directory `/tmp/madlib-1.6.0/build'
make[2]: Entering directory `/tmp/madlib-1.6.0/build'
make[3]: Entering directory `/tmp/madlib-1.6.0/build'
make[3]: Leaving directory `/tmp/madlib-1.6.0/build'
[  1%] Built target EP_eigen
make[3]: Entering directory `/tmp/madlib-1.6.0/build'
make[3]: Leaving directory `/tmp/madlib-1.6.0/build'
[  2%] Built target EP_pyxb
make[3]: Entering directory `/tmp/madlib-1.6.0/build'
make[3]: Leaving directory `/tmp/madlib-1.6.0/build'
[  2%] Built target pythonFiles
make[3]: Entering directory `/tmp/madlib-1.6.0/build'
make[3]: Leaving directory `/tmp/madlib-1.6.0/build'
[  2%] Built target sqlFiles
make[3]: Entering directory `/tmp/madlib-1.6.0/build'
make[3]: Leaving directory `/tmp/madlib-1.6.0/build'
[  2%] Built target madlibPatches
make[3]: Entering directory `/tmp/madlib-1.6.0/build'
make[3]: Leaving directory `/tmp/madlib-1.6.0/build'
(Continue reading)

Nitin Borwankar | 7 Aug 20:47 2014

[MADlib-user] compiling madlib on other platforms

Hello all,

This may sound extremely "out there" but I am curious if it is possible to
build madlib on a Raspberry Pi and bind it into Postgres.

I have run Postgres 9.1 which is installable via apt-get and am looking for
how to install 9.2 or 9.3 which may involve building on the Pi which is
rumored to take all night.
All this is on Raspbian which is a Debian Wheezy port.

Once I have the requisite Postgres can madlib be installed on it using the
usual install from source or is the ARM platform a non-starter?


Nitin Borwankar
West, Michael | 6 Aug 20:37 2014

[MADlib-user] summary function integer mfv_frequencies

I seem to be getting incorrect frequency results for integer columns using the summary function.  For
example, if I have a column of unique sequential integers of sufficient cardinality then frequencies
become greater than one as returned by the summary function. 

Select version();
PostgreSQL 9.2.8 on x86_64-unknown-linux-gnu, compiled by gcc (GCC) 4.4.7 20120313 (Red Hat 4.4.7-4), 64-bit

MadLib 1.6

Here is a script that demonstrates

--DROP TABLE summary_test;

CREATE TABLE summary_test as (
SELECT generate_series FROM generate_series(1,10000)

-- select * from summary_test;

select madlib.summary( 
    source_table := 'summary_test'::text
  , output_table := 'summary_output'::text
  , target_cols := 'generate_series'::text
  , grouping_cols := NULL::text
  , get_distinct := FALSE
  , get_quartiles := FALSE
  , ntile_array := NULL::FLOAT8[]
  , how_many_mfv := 10
(Continue reading)

Benjamin Wilson | 28 Jul 19:28 2014

[MADlib-user] nearest neighbours search in madlib

Hi all,

Does MADLib offer any facilities for nearest neighbours lookup on
vectorial data, approximate or exact?

Googling around, I found this:
But I am not sure if this is current.

Any help would be greatly appreciated!

Cheers, Benjamin.

[MADlib-user] optimal ARIMA order parameters

   I would like to know if a function has been developed to compute the optimal order for ARIMA (similar to
auto.arima - checking BIC or AIC or smallest MLE using stepwise selection process) in Madlib.

Please let me know..