Hello David, if you download and include commons-lang3.jar in your classpath Eclipse will recognize ArrayUtils and allow you to import org.apache.commons.lang3.
Here is the Javadoc for it: http://commons.apache.org/proper/commons-lang/javadocs/api-release/index.html Greetings Bernd BTW: Commons Developers: I do wonder if this would be a good feature for dbutils. It has currently a RowProcessor, but that works either in Object[] or needs to map to beans. Returning a simple type array for a single column might be usefull? Am Tue, 26 Aug 2014 11:37:12 -0400 schrieb "Kulpanowski, David" <dkulpanow...@leegov.com>: > Messrs. Worden and Eckenfels: > > Thank you both for your kind assistance. > > Mr. Worden: > your solution works perfectly. This is exactly what I am looking for. > > Mr. Eckenfels: > Please excuse my lack of java coding skills. I am working on it by > taking on projects at my job. I think your solution will work and I > want to use it in my code because I am now going to use Apache > Commons Math for more sophisticated statistics such as regression and > hypothesis testing. For example, is the mean average ambulance > response time in Cape Coral the statistically significantly different > from the mean average response time in Fort Myers. I anticipate > needing your code so I need to ask for additional help: > > In the final line of code Eclipse is putting a red underline under > ArrayUtils. > > ArrayList<Double> times = new ArrayList<>(); > while (rset.next()) > { > times.add(Double.valueOf(rset.getDouble("M_SecondsAtStatus"))); > } > double timesArray[] = ArrayUtils.toPrimitive(times.toArray()); > > My mouse hovers over it and the message is: "ArrayUtils cannot be > resolved". Eclipse offers nine quick fixes: > 1.) create class ArrayUtils. > 2.) create constant ArrayUtils > 3.) create local variable ArrayUtils > 4.) change to ArgUtils > 5.) change to Array > 6.) change to Arrays > 7.) create field ArrayUtils > 8.) create parameter ArrayUtils > 9.) fix project set up > > Which one should I use to output my data in a format Apache Commons > Math will utilize in its functions? > > > -----Original Message----- > From: Brent Worden [mailto:brent.wor...@gmail.com] > Sent: Tuesday, August 26, 2014 11:00 AM > To: Commons Users List > Subject: Re: [math] JDBC output to generate statistical results. > > Another alternative is to use a > org.apache.commons.math3.stat.descriptive.DescriptiveStatistics > object to collect all the data and then use it to compute the summary > statistics you need. Using it alleviates the need for doing all > explicit type casting and conversion: > > DescriptiveStatistics ds = new DescriptiveStatistics(); > while(rset.next()) { > int observation = rset.getInt("M_SecondsAtStatus"); > ds.addValue(observation); > } > > System.out.println("min: " + ds.getMin()); > System.out.println("max: " + ds.getMax()); ... > > HTH, > > Brent > > > On Tue, Aug 26, 2014 at 9:41 AM, Bernd Eckenfels > <e...@zusammenkunft.net> wrote: > > > Hello, > > > > First of all: Your DBMS might have SQL methods to calculate typical > > aggregates. This is not only easier to program, but also most > > likely faster and less resource intensive than doing it in an extra > > application. > > > > But since this is the commons list: If You want to use the Commons > > Math functions you have to present the set of values (in your case > > as an array). And since there is no adapter for result sets (I > > think) building the array would be done inside the loop. The most > > natural thing is to use an ArrayList to append the values in the > > loop, but then you have to convert the resulting Double[] into > > double[]. The ArrayUtils in Apache Commons Lang could do that (but > > if you need to process millions of numbers it is not the most > > efficient way to do it). > > > > untested: > > > > ArrayList<Double> times = new ArrayList<>(); > > while(rset.next()) { > > times.add(Double.valueOf(rset.getDouble(T)); > > } > > double timesArray[] = ArrayUtils.toPrimitive(times.toArray()); > > > > And then you can use this array for the Math statistics. > > > > Gruss > > bernd > > > > > > -- > > http://bernd.eckenfels.net > > > > ----- Ursprüngliche Nachricht ----- > > Von: "Kulpanowski, David" <dkulpanow...@leegov.com> > > Gesendet: 26.08.2014 15:55 > > An: "Commons Users List" <user@commons.apache.org> > > Betreff: RE: [math] JDBC output to generate statistical results. > > > > Thank you Mr. Ritter: > > > > Two issues: > > 1.) I am attempting to obtain univariate statistics from thousands > > of ambulance responses. For example, ambulance responses (in > > seconds) 534, 678, 943, 194 would be a mean of 587 seconds. Not by > > row, but rather as summary statistics. > > 2.) It appears that Apache Commons Math is needing a Double value. > > So I change it as shown below. > > Note on 2) Even though I am needing summary statistics I move the > > lines of code into the loop just to see what would happen.I just > > want to get it to work because it appears the problem is the type > > of variable (int, double, array). > > > > while (rset.next()) > > { > > double values = > > rset.getDouble("M_SecondsAtStatus"); > > System.out.println(values); > > System.out.println("min: " + > > StatUtils.min(values)); > > System.out.println("max: " + > > StatUtils.max(values)); > > System.out.println("mean: " + > > StatUtils.mean(values)); > > System.out.println("product: " + > > StatUtils.product(values)); > > System.out.println("sum: " + > > StatUtils.sum(values)); > > System.out.println("variance: " + > > StatUtils.variance(values)); > > } > > > > A red underline in Eclipse shows up and my mouse hovers over it. > > The error message is the following: > > > > "The method min(double[]) in the type StatUtils is not applicable > > for the arguments (double)" > > > > I then change the values variable to double[] as shown below: > > > > "double[] values = rset.getDouble("M_SecondsAtStatus");" > > > > java doesn't like this either. It gives a red underlined error > > message: "Type mismatch: cannot convert from double to double[]" > > > > > > I guess this boils down to two questions: > > 1.) How do I output a double[] array from database output? > > 2.) How do I output this double[] into a variable that Apache > > Commons Math will accept? > > ok, maybe three questions: > > 3.) Other people are using Apache Commons Math to understand their > > database data better. How are they doing it? A lot of guys have > > massive mainframe databases filled with health care data etc. They > > are doing sophisticated math with their data. How are they doing it? > > > > -----Original Message----- > > From: Benedikt Ritter [mailto:brit...@apache.org] > > Sent: Tuesday, August 26, 2014 9:15 AM > > To: Commons Users List > > Subject: Re: [math] JDBC output to generate statistical results. > > > > > In you're code the variable values is defined within the scope of > > > the > > while loop. > > > > D'oh worst of typos... should be "in your code" of corse ;-) > > > > 2014-08-26 15:13 GMT+02:00 Benedikt Ritter <brit...@apache.org>: > > > > > Hello David, > > > > > > the problem you're encountering is a problem with scopes. A > > > variable is only available in the scope it was defined. In you're > > > code the variable values is defined within the scope of the while > > > loop. This means, that the variable is only defined between the > > > curly brackets of > > the while loop. > > > > > > Your System.out statements try to access the values variable, > > > which is no longer accessible, since the flow of control has > > > already left the scope it was definied in (by finishing the > > > iteration over the ResultSet). > > > > > > What you need to do is move the other System.out statements into > > > the loop like so: > > > > > > > > > while (rset.next()) > > > { > > > int values = > > > rset.getInt("M_SecondsAtStatus"); System.out.println(values); > > > > > > > > > // I am hoping to derive useful > > > statistics from my database, such as > > > // the following.this uses Jakarta > > > Commons Math System.out.println("min: " + > > > StatUtils.min(values)); > > > System.out.println("max: " + > > > StatUtils.max(values)); > > > System.out.println("mean: " + > > > StatUtils.mean(values)); > > > System.out.println("product: " + > > > StatUtils.product(values)); > > > System.out.println("sum: " + > > > StatUtils.sum(values)); > > > System.out.println("variance: " + > > > StatUtils.variance(values)); > > > } > > > > > > > > > This way statistics will be printed for each row in the result > > > set. > > > > > > Regards, > > > Benedikt > > > > > > P.S.: Jakarta is an old name, that is not used any more. The name > > > of the project now is simple Apache Commons and you're using > > > Apache Commons > > Math. > > > > > > > > > 2014-08-26 15:03 GMT+02:00 Kulpanowski, David > > > <dkulpanow...@leegov.com>: > > > > > > Using jdbc I am querying my database of ambulance response times. > > > My goal > > >> is to take the output and process it into statistics using > > >> Jakarta Commons Math library. So far I am successful in querying > > >> my database and outputting the response times to the console. My > > >> next step is to process this output statistically, such as mean, > > >> medians, mode, etc. > > This is where I am stuck. > > >> What I can't figure out is how to get my database output into a > > >> format for Commons Math to generate a statistical analysis. In > > >> other words, I have > > >> 100,000 ambulance responses, now I want to do more advanced > > >> statistical analysis with this data. > > >> Shown below is my code. > > >> > > >> package javaDatabase; > > >> > > >> import java.sql.*; > > >> import org.apache.commons.math3.stat.StatUtils; > > >> > > >> public class javaConnect4 > > >> { > > >> public static void main(String[] args) > > >> { > > >> Connection conn = null; > > >> Statement stmt = null; > > >> try > > >> { > > >> conn = DriverManager > > >> > > >> > > .getConnection("jdbc:sqlserver://myServerAddress;database=myDatabase;i > > ntegratedsecurity=false;user=myUser;password=myPassword"); > > >> stmt = conn.createStatement(); > > >> String strSelect = "SELECT M_SecondsAtStatus > > >> FROM MManpower WHERE M_tTime > 'august 25, 2014' AND M_Code = > > >> 'USAR'"; > > >> > > >> ResultSet rset = > > >> stmt.executeQuery(strSelect); > > >> > > >> while (rset.next()) > > >> { > > >> int values = > > rset.getInt("M_SecondsAtStatus"); > > >> System.out.println(values); > > >> } > > >> > > >> // I am hoping to derive useful statistics > > >> from my database, such as > > >> // the following.this uses Jakarta Commons > > >> Math System.out.println("min: " + StatUtils.min(values)); > > >> System.out.println("max: " + > > >> StatUtils.max(values)); System.out.println("mean: " + > > StatUtils.mean(values)); > > >> System.out.println("product: " + > > >> StatUtils.product(values)); > > >> System.out.println("sum: " + > > >> StatUtils.sum(values)); System.out.println("variance: " + > > >> StatUtils.variance(values)); > > >> > > >> } catch (SQLException ex) > > >> { > > >> ex.printStackTrace(); > > >> } finally > > >> { > > >> try > > >> { > > >> if (stmt != null) > > >> stmt.close(); > > >> if (conn != null) > > >> conn.close(); > > >> } catch (SQLException ex) > > >> { > > >> ex.printStackTrace(); > > >> } > > >> } > > >> } > > >> } > > >> > > >> > > >> An error message pops up in Eclipse and the variable "values" is > > >> red underlined; "values cannot be resolved to a variable". > > >> I am not sure how to get this to work. > > >> I don't understand how to output my ambulance response times > > >> from the database into something Apache Commons math will > > >> understand. How can I get Apache Commons math to take the output > > >> from my database and generate a statistical result?. > > >> > > >> > > >> NOTES: > > >> 1.) I have cross-posted this question on StackOverflow.com but > > >> have not resolved the issue. > > >> 2.) I have verified that Apache Commons Math is registered in my > > >> project by hand coding a small array and using Commons Math to > > >> generate > > statistics. > > >> So Apache Math works and my database output goes to the console > > >> window, so it works also. But how do you get them to work > > >> together? 3.) I am a geographer, not a computer programmer. > > >> Believe me, you cannot make it simple enough. Please be explicit > > >> in your answers. > > >> > > >> David Kulpanowski > > >> Database Analyst > > >> Lee County EMS > > >> PO Box 398 > > >> Fort Myers, FL 33902-0398 > > >> 239-533-3962 > > >> dkulpanow...@leegov.com > > >> Longitude: -81.861486 > > >> Latitude: 26.528843 > > >> > > >> > > >> ________________________________ > > >> Please note: Florida has a very broad public records law. Most > > >> written communications to or from County Employees and officials > > >> regarding County business are public records available to the > > >> public > > and media upon request. > > >> Your email communication may be subject to public disclosure. > > >> > > >> Under Florida law, email addresses are public records. If you do > > >> not want your email address released in response to a public > > >> records request, do not send electronic mail to this entity. > > >> Instead, contact this office by phone or in writing. > > >> > > > > > > > > > > > > -- > > > http://people.apache.org/~britter/ > > > http://www.systemoutprintln.de/ > > > http://twitter.com/BenediktRitter > > > http://github.com/britter > > > > > > > > > > > -- > > http://people.apache.org/~britter/ > > http://www.systemoutprintln.de/ > > http://twitter.com/BenediktRitter > > http://github.com/britter > > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: user-unsubscr...@commons.apache.org > For additional commands, e-mail: user-h...@commons.apache.org > --------------------------------------------------------------------- To unsubscribe, e-mail: user-unsubscr...@commons.apache.org For additional commands, e-mail: user-h...@commons.apache.org
