Joel, thanks for the pointers to the streaming feature. I had no idea solr
had that (and also just discovered the very intersting sql feature! I will
be sure to investigate that in more detail in the future).
However I'm having some trouble getting basic streaming functions working.
I've already figured out that I had to move to "solr cloud" instead of
"solr standalone" because I was getting errors about "cannot find zk
instance" or whatever which went away when using "solr start -c" instead.
But now I'm trying to use the random function since that was one of the
functions used in your example.
random(tx_header, q="*:*", rows="100", fl="countyname")
I posted that directly in the "stream" section of the solr admin UI. This
is all on linux, with solr 7.1.0 and 7.2.1 (tried several versions in case
it was a bug in one)
I get back an error message:
*sort param could not be parsed as a query, and is not a field that exists
in the index: random_-255009774*
I'm not passing in any sort field anywhere. But the solr logs show these
three log entries:
2018-03-01 21:41:18.954 INFO (qtp257513673-21) [c:tx_header s:shard1
r:core_node2 x:tx_header_shard1_replica_n1] o.a.s.c.S.Request
[tx_header_shard1_replica_n1] webapp=/solr path=/select
params={q=*:*&_stateVer_=tx_header:6&fl=countyname
*&sort=random_-255009774+asc*&rows=100&wt=javabin&version=2} status=400
QTime=19
2018-03-01 21:41:18.966 ERROR (qtp257513673-17) [c:tx_header s:shard1
r:core_node2 x:tx_header_shard1_replica_n1] o.a.s.c.s.i.CloudSolrClient
Request to collection [tx_header] failed due to (400)
org.apache.solr.client.solrj.impl.HttpSolrClient$RemoteSolrException: Error
from server at http://192.168.13.31:8983/solr/tx_header: sort param could
not be parsed as a query, and is not a field that exists in the index:
random_-255009774, retry? 0
2018-03-01 21:41:18.968 ERROR (qtp257513673-17) [c:tx_header s:shard1
r:core_node2 x:tx_header_shard1_replica_n1] o.a.s.c.s.i.s.ExceptionStream
java.io.IOException:
org.apache.solr.client.solrj.impl.HttpSolrClient$RemoteSolrException: Error
from server at http://192.168.13.31:8983/solr/tx_header: sort param could
not be parsed as a query, and is not a field that exists in the index:
random_-255009774
So basically it looks like solr is injecting the "sort=random_" stuff into
my query and of course that is failing on the search since that
field/column doesn't exist in my schema. Everytime I run the random
function, I get a slightly different field name that it injects, but they
all start with "random_" etc.
I have tried adding my own sort field instead, hoping solr wouldn't inject
one for me, but it still injected a random sort fieldname:
random(tx_header, q="*:*", rows="100", fl="countyname", sort="countyname
asc")
Assuming I can fix that whole problem, my second question is: can I add
multiple "fq=" parameters to the random function? I build a pretty
complicated query using many fq= fields, and then want to run some stats on
that hitlist; so somehow I have to pass in the query that made up the exact
hitlist to these various functions, but when I used multiple "fq=" values
it only seemed to use the last one I specified and just ignored all the
previous fq's?
Thanks in advance for any comments/suggestions...!
On Fri, Feb 23, 2018 at 5:59 PM, Joel Bernstein <joels...@gmail.com> wrote:
> This is going to be a complex answer because Solr actually now has multiple
> ways of doing regression analysis as part of the Streaming Expression
> statistical programming library. The basic documentation is here:
>
> https://lucene.apache.org/solr/guide/7_2/statistical-programming.html
>
> Here is a sample expression that performs a simple linear regression in
> Solr 7.2:
>
> let(a=random(collection1, q="any query", rows="15000", fl="fieldA,
> fieldB"),
> b=col(a, fieldA),
> c=col(a, fieldB),
> d=regress(b, c))
>
>
> The expression above takes a random sample of 15000 results from
> collection1. The result set will include fieldA and fieldB in each record.
> The result set is stored in variable "a".
>
> Then the "col" function creates arrays of numbers from the results stored
> in variable a. The values in fieldA are stored in the variable "b". The
> values in fieldB are stored in variable "c".
>
> Then the regress function performs a simple linear regression on arrays
> stored in variables "b" and "c".
>
> The output of the regress function is a map containing the regression
> result. This result includes RSquared and other attributes of the
> regression model such as R (correlation), slope, y intercept etc...
>
>
>
>
>
>
>
>
>
> Joel Bernstein
> http://joelsolr.blogspot.com/
>
> On Fri, Feb 23, 2018 at 3:10 PM, John Smith <localde...@gmail.com> wrote:
>
> > Hi Joel, thanks for the answer. I'm not really a stats guy, but the end
> > result of all this is supposed to be obtaining R^2. Is there no way of
> > obtaining this value, then (short of iterating over all the results in
> the
> > hitlist and calculating it myself)?
> >
> > On Fri, Feb 23, 2018 at 12:26 PM, Joel Bernstein <joels...@gmail.com>
> > wrote:
> >
> > > Typically SSE is the sum of the squared errors of the prediction in a
> > > regression analysis. The stats component doesn't perform regression,
> > > although it might be a nice feature.
> > >
> > >
> > >
> > > Joel Bernstein
> > > http://joelsolr.blogspot.com/
> > >
> > > On Fri, Feb 23, 2018 at 12:17 PM, John Smith <localde...@gmail.com>
> > wrote:
> > >
> > > > I'm using solr, and enabling stats as per this page:
> > > > https://lucene.apache.org/solr/guide/6_6/the-stats-component.html
> > > >
> > > > I want to get more stat values though. Specifically I'm looking for
> > > > r-squared (coefficient of determination). This value is not present
> in
> > > > solr, however some of the pieces used to calculate r^2 are in the
> stats
> > > > element, for example:
> > > >
> > > > <double name="min">0.0</double>
> > > > <double name="max">10.0</double>
> > > > <long name="count">15</long>
> > > > <long name="missing">17</long>
> > > > <double name="sum">85.0</double>
> > > > <double name="sumOfSquares">603.0</double>
> > > > <double name="mean">5.666666666666667</double>
> > > > <double name="stddev">2.943920288775949</double>
> > > >
> > > >
> > > > So I have the sumOfSquares available (SST), and using this
> > calculation, I
> > > > can get R^2:
> > > >
> > > > R^2 = 1 - SSE/SST
> > > >
> > > > All I need then is SSE. Is there anyway I can get SSE from those
> other
> > > > stats in solr?
> > > >
> > > > Thanks in advance!
> > > >
> > >
> >
>
