On Nov 15, 2009, at 8:16 PM, Yonik Seeley wrote: > Let's all try to summarize changes to the wiki as we would changes to > the code - without that it's tough to tell what the changes are. > > In this particular case, I'm not sure if all of the formatting changes > were deliberate or accidental. If accidental, I wonder if the cause > was a bug in GUI mode, or a bug in your browser? >
Hmm, that is bad. I used GUI mode and I definitely did not make any of those changes. For the record, I added the dist, hsin, deg and rad functions. > -Yonik > http://www.lucidimagination.com > > > > On Sat, Nov 14, 2009 at 9:05 AM, Apache Wiki <wikidi...@apache.org> wrote: >> Dear Wiki user, >> >> You have subscribed to a wiki page or wiki category on "Solr Wiki" for >> change notification. >> >> The "FunctionQuery" page has been changed by GrantIngersoll. >> http://wiki.apache.org/solr/FunctionQuery?action=diff&rev1=29&rev2=30 >> >> -------------------------------------------------- >> >> - FunctionQuery allows one to use the actual value of a numeric field and >> functions of those fields in a relevancy score. >> + FunctionQuery allows one to use the actual value of a numeric field and >> functions of those fields in a relevancy score. >> >> <<TableOfContents>> >> >> = Using FunctionQuery = >> There are a few ways to use FunctionQuery from Solr's HTTP interface: >> + >> 1. Embed a FunctionQuery in a regular query expressed in SolrQuerySyntax >> via the _val_ hook >> 1. Use the FunctionQParserPlugin, ie: {{{q={!func}log(foo)}}} >> 1. Use a parameter that has an explicit type of FunctionQuery, such as >> DisMaxRequestHandler's '''bf''' (boost function) parameter. >> - * NOTE: the '''bf''' parameter actually takes a list of function >> queries separated by whitespace and each with an optional boost. Make sure >> to eliminate any internal whitespace in single function queries when using >> '''bf'''. >> + * NOTE: the '''bf''' parameter actually takes a list of function queries >> separated by whitespace and each with an optional boost. Make sure to >> eliminate any internal whitespace in single function queries when using >> '''bf'''. >> - * Example: {{{q=foo&bf="ord(popularity)^0.5 >> recip(rord(price),1,1000,1000)^0.3"}}} >> + * Example: {{{q=foo&bf="ord(popularity)^0.5 >> recip(rord(price),1,1000,1000)^0.3"}}} >> >> See SolrPlugins#ValueSourceParser for information on how to hook in your >> own FunctionQuery. >> >> @@ -20, +21 @@ >> >> There is currently no infix parser - functions must be expressed as >> function calls (e.g. sum(a,b) instead of a+b) >> >> = Available Functions = >> - >> == constant == >> - <!> [[Solr1.3]] >> - Floating point constants. >> + <!> [[Solr1.3]] Floating point constants. >> + >> - Example Syntax: '''1.5''' >> + . Example Syntax: '''1.5''' >> - >> - SolrQuerySyntax Example: '''_val_:1.5''' >> + SolrQuerySyntax Example: '''_val_:1.5''' >> >> == fieldvalue == >> This function returns the numeric field value of an indexed field with a >> maximum of one value per document (not multiValued). The syntax is simply >> the field name by itself. 0 is returned for documents without a value in >> the field. >> + >> - Example Syntax: '''myFloatField''' >> + . Example Syntax: '''myFloatField''' >> - >> - SolrQuerySyntax Example: '''_val_:myFloatField''' >> + SolrQuerySyntax Example: '''_val_:myFloatField''' >> >> == ord == >> ord(myfield) returns the ordinal of the indexed field value within the >> indexed list of terms for that field in lucene index order >> (lexicographically ordered by unicode value), starting at 1. In other words, >> for a given field, all values are ordered lexicographically; this function >> then returns the offset of a particular value in that ordering. The field >> must have a maximum of one value per document (not multiValued). 0 is >> returned for documents without a value in the field. >> + >> - Example: If there were only three values for a particular field: >> "apple","banana","pear", then ord("apple")=1, ord("banana")=2, ord("pear")=3 >> + . Example: If there were only three values for a particular field: >> "apple","banana","pear", then ord("apple")=1, ord("banana")=2, ord("pear")=3 >> - >> - Example Syntax: '''ord(myIndexedField)''' >> + Example Syntax: '''ord(myIndexedField)''' >> - >> - Example SolrQuerySyntax: '''_val_:"ord(myIndexedField)"''' >> + Example SolrQuerySyntax: '''_val_:"ord(myIndexedField)"''' >> >> + WARNING: as of Solr 1.4, ord() and rord() can cause excess memory use >> since they must use a FieldCache entry at the top level reader, while >> sorting and function queries now use entries at the segment level. Hence >> sorting or using a different function query, in addition to ord()/rord() >> will double memory use. >> - WARNING: as of Solr 1.4, ord() and rord() can cause excess memory use >> since they must use a FieldCache entry >> - at the top level reader, while sorting and function queries now use >> entries at the segment level. Hence sorting >> - or using a different function query, in addition to ord()/rord() will >> double memory use. >> - >> >> WARNING: ord() depends on the position in an index and can thus change when >> other documents are inserted or deleted, or if a !MultiSearcher is used. >> >> == rord == >> The reverse ordering of what ord provides. >> + >> - Example Syntax: '''rord(myIndexedField)''' >> + . Example Syntax: '''rord(myIndexedField)''' >> - >> - Example: '''rord(myDateField)''' is a metric for how old a document >> is: the youngest document will return 1, the oldest document will return the >> total number of documents. >> + Example: '''rord(myDateField)''' is a metric for how old a document is: >> the youngest document will return 1, the oldest document will return the >> total number of documents. >> >> + WARNING: as of Solr 1.4, ord() and rord() can cause excess memory use >> since they must use a FieldCache entry at the top level reader, while >> sorting and function queries now use entries at the segment level. Hence >> sorting or using a different function query, in addition to ord()/rord() >> will double memory use. >> - >> - WARNING: as of Solr 1.4, ord() and rord() can cause excess memory use >> since they must use a FieldCache entry >> - at the top level reader, while sorting and function queries now use >> entries at the segment level. Hence sorting >> - or using a different function query, in addition to ord()/rord() will >> double memory use. >> >> == sum == >> - <!> [[Solr1.3]] >> - sum(x,y,...) returns the sum of multiple functions. >> + <!> [[Solr1.3]] sum(x,y,...) returns the sum of multiple functions. >> + >> - Example Syntax: '''sum(x,1)''' >> + . Example Syntax: '''sum(x,1)''' >> - >> - Example Syntax: '''sum(x,y)''' >> + Example Syntax: '''sum(x,y)''' >> - >> - Example Syntax: '''sum(sqrt(x),log(y),z,0.5)''' >> + Example Syntax: '''sum(sqrt(x),log(y),z,0.5)''' >> >> == sub == >> - <!> [[Solr1.4]] >> - sub(x,y) returns x-y >> + <!> [[Solr1.4]] sub(x,y) returns x-y >> + >> - Example: '''sub(myfield,myfield2)''' >> + . Example: '''sub(myfield,myfield2)''' >> - >> - Example: '''sub(100,sqrt(myfield))''' >> + Example: '''sub(100,sqrt(myfield))''' >> >> == product == >> - <!> [[Solr1.3]] >> - product(x,y,...) returns the product of multiple functions. >> + <!> [[Solr1.3]] product(x,y,...) returns the product of multiple functions. >> + >> - Example Syntax: '''product(x,2)''' >> + . Example Syntax: '''product(x,2)''' >> - >> - Example Syntax: '''product(x,y)''' >> + Example Syntax: '''product(x,y)''' >> >> == div == >> - <!> [[Solr1.3]] >> - div(x,y) divides the function x by the function y. >> + <!> [[Solr1.3]] div(x,y) divides the function x by the function y. >> + >> - Example Syntax: '''div(1,x)''' >> + . Example Syntax: '''div(1,x)''' >> - >> - Example Syntax: '''div(sum(x,100),max(y,1))''' >> + Example Syntax: '''div(sum(x,100),max(y,1))''' >> >> == pow == >> - <!> [[Solr1.3]] >> - pow(x,y) raises the base x to the power y. >> + <!> [[Solr1.3]] pow(x,y) raises the base x to the power y. >> + >> - Example Syntax: '''pow(x,0.5)''' same as sqrt >> + . Example Syntax: '''pow(x,0.5)''' same as sqrt >> - >> - Example Syntax: '''pow(x,log(y))''' >> + Example Syntax: '''pow(x,log(y))''' >> >> == abs == >> - <!> [[Solr1.3]] >> - abs(x) returns the absolute value of a function. >> + <!> [[Solr1.3]] abs(x) returns the absolute value of a function. >> + >> - Example Syntax: '''abs(-5)''' >> + . Example Syntax: '''abs(-5)''' >> - >> - Example Syntax: '''abs(x)''' >> + Example Syntax: '''abs(x)''' >> >> == log == >> - <!> [[Solr1.3]] >> - log(x) returns log base 10 of the function x. >> + <!> [[Solr1.3]] log(x) returns log base 10 of the function x. >> + >> - Example Syntax: '''log(x)''' >> + . Example Syntax: '''log(x)''' >> - >> - Example Syntax: '''log(sum(x,100))''' >> + Example Syntax: '''log(sum(x,100))''' >> >> == sqrt == >> - <!> [[Solr1.3]] >> - sqrt(x) returns the square root of the function x >> + <!> [[Solr1.3]] sqrt(x) returns the square root of the function x >> + >> - Example Syntax: '''sqrt(2)''' >> + . Example Syntax: '''sqrt(2)''' >> - >> - Example Syntax: '''sqrt(sum(x,100))''' >> + Example Syntax: '''sqrt(sum(x,100))''' >> >> == map == >> - <!> [[Solr1.3]] >> - map(x,min,max,target) maps any values of the function x that fall within >> min and max inclusive to target. min,max,target are constants. It outputs >> the field's value if it does not fall between min and max. >> + <!> [[Solr1.3]] map(x,min,max,target) maps any values of the function x >> that fall within min and max inclusive to target. min,max,target are >> constants. It outputs the field's value if it does not fall between min and >> max. >> + >> - Example Syntax 1: '''map(x,0,0,1)''' change any values of 0 to 1... >> useful in handling default 0 values >> + . Example Syntax 1: '''map(x,0,0,1)''' change any values of 0 to 1... >> useful in handling default 0 values >> - >> - Example Syntax 2 <!> [[Solr1.4]]: '''map(x,0,0,1,0)''' change any >> values of 0 to 1 . and if the value is not zero it can be set to the value >> of the 5th argument instead of defaulting to the field's value >> + Example Syntax 2 <!> [[Solr1.4]]: '''map(x,0,0,1,0)''' change any values >> of 0 to 1 . and if the value is not zero it can be set to the value of the >> 5th argument instead of defaulting to the field's value >> - >> - >> - >> >> == scale == >> - <!> [[Solr1.3]] >> - scale(x,minTarget,maxTarget) scales values of the function x such that >> they fall between minTarget and maxTarget inclusive. >> + <!> [[Solr1.3]] scale(x,minTarget,maxTarget) scales values of the function >> x such that they fall between minTarget and maxTarget inclusive. >> - Example Syntax: '''scale(x,1,2)''' all values will be between 1 and 2 >> inclusive. >> >> - NOTE: The current implementation currently traverses all of the >> function values to obtain the min and max so it can pick the correct scale. >> + . Example Syntax: '''scale(x,1,2)''' all values will be between 1 and 2 >> inclusive. NOTE: The current implementation currently traverses all of the >> function values to obtain the min and max so it can pick the correct scale. >> - >> - NOTE: This implementation currently cannot distinguish when documents >> have been deleted or documents that have no value, and 0.0 values will be >> used for these cases. This means that if values are normally all greater >> than 0.0, one can still end up with 0.0 as the min value to map from. In >> these cases, an appropriate map() function could be used as a workaround to >> change 0.0 to a value in the real range. example: >> '''scale(map(x,0,0,5),1,2)''' >> + NOTE: This implementation currently cannot distinguish when documents >> have been deleted or documents that have no value, and 0.0 values will be >> used for these cases. This means that if values are normally all greater >> than 0.0, one can still end up with 0.0 as the min value to map from. In >> these cases, an appropriate map() function could be used as a workaround to >> change 0.0 to a value in the real range. example: >> '''scale(map(x,0,0,5),1,2)''' >> >> == query == >> - <!> [[Solr1.4]] >> - query(subquery, default) returns the score for the given subquery, or the >> default value for documents not matching the query. Any type of subquery is >> supported through either parameter dereferencing {{{$otherparam}}} or direct >> specification of the query string in the LocalParams via "v". >> + <!> [[Solr1.4]] query(subquery, default) returns the score for the given >> subquery, or the default value for documents not matching the query. Any >> type of subquery is supported through either parameter dereferencing >> {{{$otherparam}}} or direct specification of the query string in the >> LocalParams via "v". >> >> - Example Syntax: '''q=product(popularity, query({!dismax v='solr >> rocks'})''' returns the product of the popularity and the score of the >> dismax query. >> + . Example Syntax: '''q=product(popularity, query({!dismax v='solr >> rocks'})''' returns the product of the popularity and the score of the >> dismax query. >> - >> - Example Syntax: '''q=product(popularity, query($qq))&qq={!dismax}solr >> rocks''' is equivalent to the previous query, using param dereferencing. >> + Example Syntax: '''q=product(popularity, query($qq))&qq={!dismax}solr >> rocks''' is equivalent to the previous query, using param dereferencing. >> - >> - Example Syntax: '''q=product(popularity, >> query($qq,0.1))&qq={!dismax}solr rocks''' specifies a default score of 0.1 >> for documents that don't match the dismax query. >> + Example Syntax: '''q=product(popularity, query($qq,0.1))&qq={!dismax}solr >> rocks''' specifies a default score of 0.1 for documents that don't match the >> dismax query. >> >> == linear == >> linear(x,m,c) implements m*x+c where m and c are constants and x is an >> arbitrary function. This is equivalent to '''sum(product(m,x),c)''', but >> slightly more efficient as it is implemented as a single function. >> + >> - Example Syntax: '''linear(x,2,4)''' returns 2*x+4 >> + . Example Syntax: '''linear(x,2,4)''' returns 2*x+4 >> >> == recip == >> A reciprocal function with '''recip(x,m,a,b)''' implementing a/(m*x+b). >> m,a,b are constants, x is any numeric field or arbitrarily complex function. >> >> When a and b are equal, and x>=0, this function has a maximum value of 1 >> that drops as x increases. Increasing the value of a and b together results >> in a movement of the entire function to a flatter part of the curve. These >> properties can make this an ideal function for boosting more recent >> documents when x is rord(datefield). >> + >> - Example Syntax: '''recip(rord(creationDate),1,1000,1000)''' >> + . Example Syntax: '''recip(rord(creationDate),1,1000,1000)''' >> >> - <!> [[Solr1.4]] >> - In Solr 1.4 and later, best practice is to avoid ord() and rord() and >> derive the boost directly from the value of the date field. >> + <!> [[Solr1.4]] In Solr 1.4 and later, best practice is to avoid ord() and >> rord() and derive the boost directly from the value of the date field. See >> ms() for more details. >> - See ms() for more details. >> >> == max == >> max(x,c) returns the max of another function and a constant. Useful for >> "bottoming out" another function at some constant. >> + >> - Example Syntax: '''max(myfield,0)''' >> + . Example Syntax: '''max(myfield,0)''' >> >> == ms == >> <!> [[Solr1.4]] >> @@ -175, +149 @@ >> >> Arguments may be numerically indexed date fields such as !TrieDate (the >> default in 1.4), or date math (examples in SolrQuerySyntax) based on a >> constant date or '''NOW'''. >> >> '''ms()''' >> + >> - Equivalent to '''ms(NOW)''', number of milliseconds since the epoch. >> + . Equivalent to '''ms(NOW)''', number of milliseconds since the epoch. >> + >> '''ms(a)''' >> + >> - Returns the number of milliseconds since the epoch that the argument >> represents. >> + . Returns the number of milliseconds since the epoch that the argument >> represents. >> - >> - Example: '''ms(NOW/DAY)''' >> + Example: '''ms(NOW/DAY)''' >> - >> - Example: '''ms(2000-01-01T00:00:00Z)''' >> + Example: '''ms(2000-01-01T00:00:00Z)''' >> - >> - Example: '''ms(mydatefield)''' >> + Example: '''ms(mydatefield)''' >> + >> '''ms(a,b)''' >> + >> - Returns the number of milliseconds that {{{b}}} occurs before {{{a}}} >> (i.e. {{{a - b}}}). Note that this offers higher precision than >> '''sub(a,b)''' because the arguments are not converted to floating point >> numbers before subtraction. >> + . Returns the number of milliseconds that {{{b}}} occurs before {{{a}}} >> (i.e. {{{a - b}}}). Note that this offers higher precision than >> '''sub(a,b)''' because the arguments are not converted to floating point >> numbers before subtraction. >> - >> - Example: '''ms(NOW,mydatefield)''' >> + Example: '''ms(NOW,mydatefield)''' >> - >> - Example: '''ms(mydatefield,2000-01-01T00:00:00Z)''' >> + Example: '''ms(mydatefield,2000-01-01T00:00:00Z)''' >> - >> - Example: '''ms(datefield1,datefield2)''' >> + Example: '''ms(datefield1,datefield2)''' >> + >> + == dist == >> + [[Solr1.5]] >> + >> + Return the Distance between two Vectors (points) in an n-dimensional >> space. See http://en.wikipedia.org/wiki/Lp_space for more information. >> Takes in the power, plus two or more !ValueSource instances and calculates >> the distances between the two vectors. Each !ValueSource must be a number. >> + >> + Common cases: >> + >> + ||<tablestyle="width: 467px; height: 88px;">Power ||Common Name || >> + ||0 ||Sparseness calculation || >> + ||1||Manhattan (taxicab) Distance|| >> + ||2||Euclidean Distance|| >> + ||Infinite||Infinite norm - maximum value in the vector|| >> + >> + >> >> === Date Boosting === >> Boosting more recent content is a common use case. One way is to use a >> {{{recip}}} function in conjunction with {{{ms}}}. >> @@ -203, +191 @@ >> >> Also see >> http://wiki.apache.org/solr/SolrRelevancyFAQ#How_can_I_boost_the_score_of_newer_documents >> >> == top == >> - <!> [[Solr1.4]] >> - Causes it's function query argument to derive it's values from the >> top-level IndexReader containing all parts of an index. For example, the >> ordinal of a value in a single segment will be different from the ordinal of >> that same value in the complete index. The ord() and rord() functions >> implicitly use top() and hence ord(foo) is equivalent to top(ord(foo)). >> + <!> [[Solr1.4]] Causes it's function query argument to derive it's values >> from the top-level IndexReader containing all parts of an index. For >> example, the ordinal of a value in a single segment will be different from >> the ordinal of that same value in the complete index. The ord() and rord() >> functions implicitly use top() and hence ord(foo) is equivalent to >> top(ord(foo)). >> >> = General Example = >> - >> - To give more idea about the use of the function query, suppose index >> stores dimensions in meters '''x''', '''y''','''z''' of some hypothetical >> boxes with arbitrary names stored in field '''boxname'''. >> + To give more idea about the use of the function query, suppose index >> stores dimensions in meters '''x''', '''y''','''z''' of some hypothetical >> boxes with arbitrary names stored in field '''boxname'''. Suppose we want to >> search for box matching name ''findbox'' but ranked according to volumes of >> boxes, the query params would be: >> - Suppose we want to search for box matching name ''findbox'' but ranked >> according to volumes of boxes, the query params would be: >> + >> {{{ >> q=boxname:findbox+_val_:"product(product(x,y),z)" >> }}} >> - >> Although this will rank the results based on volumes but in order to get >> the computed volume you will need to add parameter... >> + >> {{{ >> &fl=*,score >> }}} >> - >> ...where '''score''' will contain the resultant volume. >> >> Suppose you also have a field containing weight of the box as 'weight', >> then to sort by the density of the box and return the value of the density >> in score you query should be... >> @@ -226, +211 @@ >> >> {{{ >> >> http://localhost:8983/solr/select/?q=boxname:findbox+_val_:"div(weight,product(product(x,y),z))"&fl=boxname,x,y,z,weight,score >> }}} >> - >> >> -------------------------- Grant Ingersoll http://www.lucidimagination.com/ Search the Lucene ecosystem (Lucene/Solr/Nutch/Mahout/Tika/Droids) using Solr/Lucene: http://www.lucidimagination.com/search
