[math] JDBC output to generate statistical results.
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;integratedsecurity=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.
Re: [math] JDBC output to generate statistical results.
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;integratedsecurity=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
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;integratedsecurity=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
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
Re: [math] JDBC output to generate statistical results.
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:
ArrayListDouble 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
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:
ArrayListDouble 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
RE: [math] JDBC output to generate statistical results.
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.
ArrayListDouble 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:
ArrayListDouble 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
[BCEL] Disassembling code
Hello, I'm currently developing an application that trace java code using JDI API and wish be able to disassemble code being traced. BCEL has such a functionality in the form of Utility.codeToString() method. Problem: The codeToString() requires ConstantPool instance while ConstantPool(DataInputStream) constructor has package-level visibility and no utility method to construct constant pool from byte[] provided. Of course ConstantPool can be subclassed with descendant in same package but this is definitely a hack. What solution you might suggest? I presonally tend to add new factory method constructing ConstantPool from byte[] to the Utility.java but it is unclear to me how to submit a patch to the BCEL.
Re: [BCEL] Disassembling code
Maxim, You can start here: http://commons.apache.org/patches.html Make sure you check out the trunk code and attach your patch with unit tests to a JIRA issue. Gary On Tue, Aug 26, 2014 at 11:39 AM, Maxim Degtyarev mdegtya...@gmail.com wrote: Hello, I'm currently developing an application that trace java code using JDI API and wish be able to disassemble code being traced. BCEL has such a functionality in the form of Utility.codeToString() method. Problem: The codeToString() requires ConstantPool instance while ConstantPool(DataInputStream) constructor has package-level visibility and no utility method to construct constant pool from byte[] provided. Of course ConstantPool can be subclassed with descendant in same package but this is definitely a hack. What solution you might suggest? I presonally tend to add new factory method constructing ConstantPool from byte[] to the Utility.java but it is unclear to me how to submit a patch to the BCEL. -- E-Mail: garydgreg...@gmail.com | ggreg...@apache.org Java Persistence with Hibernate, Second Edition http://www.manning.com/bauer3/ JUnit in Action, Second Edition http://www.manning.com/tahchiev/ Spring Batch in Action http://www.manning.com/templier/ Blog: http://garygregory.wordpress.com Home: http://garygregory.com/ Tweet! http://twitter.com/GaryGregory
Re: [math] JDBC output to generate statistical results.
On 8/26/14 8:37 AM, Kulpanowski, David wrote:
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.
ArrayListDouble 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?
Are you perhaps trying to use ArrayUtils from commons lang? In that
case, you need to import that class from lang. But as Brent
suggested, it would be easier for you in this case not to build the
list of values at all, but just add them to a DescriptiveStatistics
(or SummaryStatistics) instance that will accumulate stats based on
the stream of values that you give it using addValue(double). The
difference between DescriptiveStatistics and SummaryStatistics is
that the first one stores the full dataset in memory, so can provide
a few more statistics. SummaryStatistics does not store the full
data array so can be used with very large samples.
Phil
-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:
ArrayListDouble 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())
Re: [math] JDBC output to generate statistical results.
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.
ArrayListDouble 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:
ArrayListDouble 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())
{
