Sum of an array
Hey guys,
So I have an array with six values stored in them.
The values will either be 1 or 0.
I need to sum them up so that I get a number ranging from 0-6.
Any help on this rather noob question would be much appreciated!
just loop thru the array and add them up...
var arraySum:Number = 0;
for (var i:uint=0; i< yourArray.length; i++){
arraySum += yourArray[i];
Similar Messages
-
Need help finding the sum of an array list
I'm making a mock up of iTunes, I suppose, for class. My only issue is that I can't figure out how to add all the durations of each sound file when it's stated in the array.
I've put the part I'm having trouble with in bold, it is located in the Jpod class. We're using a program called BlueJ for coding, which is why the commenting is slightly odd.
import java.applet.*;
import java.io.*;
import java.net.*;
public class SoundPlayer
public SoundPlayer(String fileName, int duration)
AudioClip testClip;
URL testUrl;
System.out.println("Playing " + fileName);
try{
testUrl=new URL("file:" + new File(".").getCanonicalPath() + "/" + fileName);
testClip=Applet.newAudioClip(testUrl);
testClip.play();
Thread.sleep(duration*1000);
testClip.stop();
}catch(Exception e){ System.out.println(e.toString()); }
public class Sound
private String author;
private String fileName;
private int duration;
* Constructor for objects of class Sound
public Sound(String newAuthor, String newFileName, int newDuration)
// initialise instance variables
author = newAuthor;
fileName = newFileName;
duration = newDuration;
* Returns the duration of the sound file
* @return duration of the sound file
public int getDuration()
// returns duration
return duration;
* Returns the author of the sound file
* @return author of the sound file
public String getAuthor()
//returns author
return author;
* Prints the author, filename, and duration
public void printSound()
System.out.println("Author: " + author + " File name: " + fileName + " Duration: " + duration);
* Plays the sound
* @return sound file
public void playSound()
new SoundPlayer("Lab4.wav",3);
import java.util.ArrayList;
import java.util.Iterator;
public class Jpod
// instance variables - replace the example below with your own
private ArrayList<Sound> playlists;
* Constructor for objects of class Jpod
public Jpod()
playlists = new ArrayList<Sound>();
* Adds a sound to the playlist
* @param sound of type Sound
public void addSound(Sound sound)
// inserts the sound into the playlist
playlists.add(sound);
* Adds 3 sounds to a playlist
public void createPlayList()
Sound s;
s = new Sound("Microsoft", "Lab4.wav", 2);
addSound(s);
s = new Sound("Dr. Evil", "DrEvil.wav", 4);
addSound(s);
s = new Sound("Arnold Schwarzenegger", "Terminator.wav", 2);
addSound(s);
* Remove desired sound object
* @param indexNumber The number of the sound object to be removed
public void removeSound(int indexNumber)
if(indexNumber < 0){
//Not a valid index number - do nothing
else if(indexNumber < playlists.size()){
//Valid indexNumber
playlists.remove(indexNumber);
else {
//Not a valid index number - do nothing
* Show the sound object
* @param indexNumber The number of the sound object to be shown
public void getSound(int indexNumber)
if(indexNumber < 0){
//Not a valid index number - do nothing
else if(indexNumber < playlists.size()){
//Valid indexNumber
System.out.println(playlists.get(indexNumber));
else {
//Not a valid index number - do nothing
* @return The number of sounds in the playlist
public int getSize()
return playlists.size();
* List all sounds in the playlist
public void indexPrintList()
for(Sound playlist : playlists) {
playlist.printSound();
* Lists all sounds in the playlist using an iterator
public void iteratorPrintList()
Iterator<Sound> iter = playlists.iterator();
while(iter.hasNext()) {
((Sound)iter.next()).printSound();
* Gives the total duration of all sounds in the playlist
*public void totalDuration()*
*//currently prints all durations - still working on sum*
*for(Sound playlist : playlists) {*
*System.out.println(playlist.getDuration());*
* Plays through all the sounds in the playlist
* Extra Credit
public void indexPlayList()
for(Sound playlist : playlists) {
playlist.playSound();
* Plays through all sounds in the playlist using an iterator
* Extra Credit
public void iteratorPlayList()
Iterator<Sound> iter = playlists.iterator();
while(iter.hasNext()) {
((Sound)iter.next()).playSound();
}not sure if I'm missing something here, but this could possibly be solved by initializing a variable to 0 before the for loop, and then adding each duration to this variable as you loop. This seems too trivial a solution though. Again, I may be missing something here.
something simple like:
public void calcSum()
int i = 0;
for(Fubar foo: fooList) {
i += foo.getLength();
System.out.println("Sum = " + i);
}Edited by: petes1234 on Oct 23, 2007 9:09 AM -
Perculiar results of finding max sum of an array
hi.
I am doing an assigment of the time complexity of finding maxsum of an array. However, the time that i got for N log N algorithm is faster than the time of a N algorithm. Is there any reason with that? The same code is run on another machine but do that have the funny result. I am using a Microsoft Windows XP Professional, Laptop @ 1.4GHz of processor, Intel� 855GM chipset, 512MB DDR
Further to that, what is a time complexity formula? Do we follow a certain standard to getting the formula?And what does that have to do with the javadoc tool, which this forum is for?
-
Im trying to sum a 2D array by column
Say I have 5 rows and 5 columns im trying to get the sum of all the values in the second column.
What I have so far and have been hassling with for a while is:
public static float sumCol(int[][] table, int rowsize, int colsize)
int[] c = new int[colsize];
float sum=0;
for (int row=0; row < rowsize; row++)
for (int col=0; col < colsize; col++)
c[col] = table [row][col];
sum = myMethods.sum(c);
return sum;the sum method calculates the sum of an array
If you can help me and just give me some pointers on how to get this, 2D arrays I think play tricks on your mind.I dont understand why this is giving an out of bounds
when i call it
public static float sumCol(int[][] table, int
rowsize, int colsize)
int[] c = new int[colsize];
float sum=0;
for (int row=0; row < rowsize; row++)
c[row] = table [row][colsize];
sum = myMethods.sum(c);
return sum;
Because number of columns is not the same as number of rows.
I still don't understand why you are creating an array. You don't need one.
Kaj -
Hi
I have an object called monitorPlot_0 on which I want to add i/b objects called reportMonitor_i.
for ( b = 0; b =< 2; b = b + 1) {
i = 0;
for ( h = 0.5; h <= 2; h = h + 0.5) {
i = b*i + 1;
a=0;
MonitorPlot monitorPlot_0 =
simulation_0.getPlotManager().createMonitorPlot();
monitorPlot_0.setPresentationName("Reports Plot Unit " + b +" "+ h + "m");
ReportMonitor reportMonitor_i =
areaAverageReport_i.createMonitor();
monitorPlot_b.getMonitors().addObjects(reportMonitor_i);
// monitorPlot_0.getMonitors().addObjects(reportMonitor_0, reportMonitor_1, reportMonitor_2, reportMonitor_3);
}I have a problem with this line which is wrong, I don't know how to code it properly:
monitorPlot_b.getMonitors().addObjects(reportMonitor_i);I want to add i/b objects called reportMonitor_i in each monitorPlot_b, in this example, that's would create the following monitorPlot at the end:
monitorPlot_0.getMonitors().addObjects(reportMonitor_0, reportMonitor_1, reportMonitor_2, reportMonitor_3);
monitorPlot_1.getMonitors().addObjects(reportMonitor_4, reportMonitor_5, reportMonitor_6, reportMonitor_7);
monitorPlot_2.getMonitors().addObjects(reportMonitor_8, reportMonitor_9, reportMonitor_10, reportMonitor_11);
How can I create a sum or an array or something that stores 4 reportMonitors and then put these 4 reportMonitors into the monitor plot?I'm still having a tough time figuring out what exactly it is that you want. Your code however seems array-deficient. Everywhere I see an underscore-number, I'm thinking that an array would go nicely there. I also am not a fan of your for loop that uses a floating point number (h) as its index, especially if it is relying on an == or equal variant (<= or >=) as its terminating condition since == is hard to come by with floating point numbers. I think much more reliable is to use an int for loop and then calculate your "h" or height when you need it. Something like,
for (int apartment = 0; apartment < monitorPlots.length; apartment++) {
int i = 0;
monitorPlots[apartment] = simulations[apartment].getPlotManager()
.createMonitorPlot();
for (int level = 0; level < 4; level++) {
double height = 0.5 + level * 0.5;
MonitorPlot monitorPlot = new MonitorPlot(apartment, height);
monitorPlots[apartment].add(apartment, monitorPlot);
}Also, please consider using variable names that make sense, that auto-comment the code for you.
edit: also 2: consider looking into using ArrayLists. They're sort of like flexible arrays that can have changing number of items held in them.
also 3: Please look over this link -- [How To Ask Questions The Smart Way|http://catb.org/~esr/faqs/smart-questions.html] -- it may seem smarmy of me to give you a link to this, but if you read it, you will see that it can help you to write questions here that people will be better able to answer, that folks will want to answer. I know that it's helped me. I try to re-read this link about once a month.
As always, much luck.
Edited by: Encephalopathic on Aug 13, 2009 8:33 PM -
Can some please help with this. I need to pass an array to a
wsdl function. The type is an array of single byte elements in
chunks of 300 KB or less.
I was able to read the data (From XML file) and converted it
to a 1 dimension data array. How can I determine what the size of
that dataarray? And also is it even possible to break that array
out into 300 KB Chunks?
Thanks,
JimmyRemember my first day of getting into programming class.
So here is the code for you:
public class DataArray extends Object {
// return Sum of the array elements
public static double getSum(double [] a) {
double sum = 0;
for ( int i=0; i<a.length; i++) {
sum += a;
return sum;
// return Average of the array elements
public static double getAverage(double [] a) {
return getSum(a)/a.length;
// return Minimum of the array elements
public static double getMinimum(double [] a) {
double min = a[0];
for ( int i=1; i<a.length; i++) {
if ( a[i] < min ) min = a[i];
return min; -
How do I get the variable checkNumber to read from the input and exit if the user enters a value less than 0? I initially created the array to accept 10 integer values and then average and sum them using JOptionPane. Now I would like the user to be able to exit the program if a negative value is entered in the input. Here's how it looks so far and I understand the if statement is where I am losing it.
import java.text.NumberFormat;
import java.text.DecimalFormat;
import javax.swing.*;
class originalArray
public static void main(String args[])
int checkNumber;
int inputArray[] = new int[10];
int arrayLength = inputArray.length;
Boolean keepRunning = true;
while (keepRunning)
for(int i=0;i<arrayLength;i++)
inputArray=Integer.parseInt(JOptionPane.showInputDialog("Enter integer for array location "+i+" :"));
//checkNumber = inputArray;
if (checkNumber <0)
System.exit(0);
else
{int sum = 0;
String loc = "";
for(int i=0; i<arrayLength; i++)
sum+= inputArray[i];
loc+= "Array location " + i + " is " + inputArray[i] + "\n";
double avg;
NumberFormat formatter = new DecimalFormat ("#0.000");
avg =(double)sum/10;
JOptionPane.showMessageDialog (null, loc + "The sum or the array is " + sum + "\n The average of the array is " + formatter.format(avg));import javax.swing.*;
import java.text.*;
class OriginalArray
public static void main(String args[])
int checkNumber=0;
int inputArray[] = new int[10];
int arrayLength = inputArray.length;
Boolean keepRunning = true;
int sum = 0;
String loc = "";
while (keepRunning)
for(int i=0;i<arrayLength;i++)
inputArray=Integer.parseInt(JOptionPane.showInputDialog("Enter integer for array location "+i+" :"));
checkNumber = inputArray[i];
if (checkNumber <0)
System.exit(0);
else
continue;
for(int i=0; i<arrayLength; i++)
sum+= inputArray[i];
loc+= "Array location " + i + " is " + inputArray[i] + "\n";
double avg;
NumberFormat formatter = new DecimalFormat ("#0.000");
avg =(double)sum/10;
JOptionPane.showMessageDialog (null, loc + "The sum or the array is " + sum + "\n The average of the array is " + formatter.format(avg));
keepRunning=false;
bye -
No class method output... HELP!!!
hi to everyone...
how can i output the classes in the main class???
the output i get is zero and i cannot figure out why...
here is my code:
//============================================================
import java.io.*;
import javax.swing.*;
class methodmin{
public static void makemin (int[] minimum){
int min;
int[] array = new int[10];
// initialize the current minimum
min = array[0];
// scan the array
for ( int index=0; index < array.length; index++ )
if ( array[ index ] < min )
min = array[ index ] ;
JOptionPane.showMessageDialog(null,"Minimum of the array is: " + min
+ "\n"
,"Single Dimension Array"
,JOptionPane.INFORMATION_MESSAGE);
class methodmax{
public static void makemax (int[] maximum){
int[] array = new int[10];
int max;
// initialize the current maximum
max = array[0];
// scan the array
for ( int index=0; index < array.length; index++ )
if ( array[ index ] > max ) // examine the current element
max = array[ index ]; // if it is the largest so far, change max
JOptionPane.showMessageDialog(null,"Maximum of the array is: " + max
+ "\n"
,"Single Dimension Array"
,JOptionPane.INFORMATION_MESSAGE);
class methodsum{
public static void makesum (int[] sum){
int[] array = new int[10];
// declare and initialize the total
int total = 0 ;
// add each element of the array to the total
for ( int index=0; index < array.length; index++ )
total = total + array[ index ] ;
JOptionPane.showMessageDialog(null,"Sum of the array is: " + total
+ "\n"
,"Single Dimension Array"
,JOptionPane.INFORMATION_MESSAGE);
class methodave{
public static void makeave (int[] ave){
int[] array = new int[10];
// declare and initialize the total
int total = 0 ;
int index=0;
// add each element of the array to the total
for ( index=0; index < array.length; index++ )
total = total + array[ index ] ;
if ( array.length <= 0 )
JOptionPane.showMessageDialog(null,"Average of the array is: " + total/array[index]
+ "\n"
,"Single Dimension Array"
,JOptionPane.INFORMATION_MESSAGE);
else
JOptionPane.showMessageDialog(null,"The array contains no elements "
,"Single Dimension Array"
,JOptionPane.INFORMATION_MESSAGE);
class mainmenu{
public static void main(String[] args) {
int i=0;
int rep=0;
int numba;
String temp="";
int[] anArray;
anArray = new int[10];
methodmin fmin = new methodmin();
methodmax fmax = new methodmax();
methodsum fsum = new methodsum();
methodave fave = new methodave();
JOptionPane.showMessageDialog(null,"This is a program that will \n"
+ "display the Minimum, Maximum, \n"
+ "Sum and Average numbers in a \n"
+ "Single Dimension Array \n"
+ "Using Objects and Classes"
,"Single Dimension Array"
,JOptionPane.INFORMATION_MESSAGE);
do{
for(i=0; i<=9; i++)
anArray=Integer.parseInt(JOptionPane.showInputDialog(null,"Enter ten numbers"
,"Single Dimension Array"
,JOptionPane.QUESTION_MESSAGE));
numba = anArray[0];
for(i=0; i<=9; i++)
numba = anArray[i];
temp=temp+"\n"+numba;
JOptionPane.showMessageDialog(null,"The Numbers Entered Are: " + temp
+ "\n"
,"Single Dimension Array"
,JOptionPane.INFORMATION_MESSAGE);
fmin.makemin(anArray);
fmax.makemax(anArray);
fsum.makesum(anArray);
fave.makeave(anArray);
rep = JOptionPane.showConfirmDialog (null,"Input another number?"
,"Single Dimension Array"
,JOptionPane.YES_NO_OPTION);
while(rep==0);ive taken all your advices and guess what, the code now works!!! thanks to all of you who helped, more power and god bless!!!
my problem now is on how to output the average... this is a bit tricky for me because i think i have to output it as a double or with decimal numbers...
any ideas???
===========================================================
import java.io.*;
import javax.swing.*;
class methodmin{
public static int makemin (int[] minimum){
int min;
// initialize the current minimum
min = minimum[0];
// scan the array
for ( int index=0; index < minimum.length; index++ )
if ( minimum[ index ] < min )
min = minimum[ index ] ;
JOptionPane.showMessageDialog(null,"Minimum of the array is: " + min
+ "\n"
,"Single Dimension Array"
,JOptionPane.INFORMATION_MESSAGE);
return min;
class methodmax{
public static int makemax (int[] maximum){
int max;
// initialize the current maximum
max = maximum[0];
// scan the array
for ( int index=0; index < maximum.length; index++ )
if ( maximum[ index ] > max ) // examine the current element
max = maximum[ index ]; // if it is the largest so far, change max
JOptionPane.showMessageDialog(null,"Maximum of the array is: " + max
+ "\n"
,"Single Dimension Array"
,JOptionPane.INFORMATION_MESSAGE);
return max;
class methodsum{
public static int makesum (int[] sum){
// declare and initialize the total
int total = 0 ;
// add each element of the array to the total
for ( int index=0; index < sum.length; index++ )
total = total + sum[ index ] ;
JOptionPane.showMessageDialog(null,"Sum of the array is: " + total
+ "\n"
,"Single Dimension Array"
,JOptionPane.INFORMATION_MESSAGE);
return total;
class methodave{
public static int makeave (int[] ave){
// declare and initialize the total
int total = 0 ;
int index= 0;
// add each element of the array to the total
for ( index=0; index < ave.length ; index++ )
total = total + ave[ index ] ;
if ( ave.length <= 0 )
JOptionPane.showMessageDialog(null,"Average of the array is: " + total/ave[index]
+ "\n"
,"Single Dimension Array"
,JOptionPane.INFORMATION_MESSAGE );
else
JOptionPane.showMessageDialog (null,"The array contains no elements "
,"Single Dimension Array"
, JOptionPane.INFORMATION_MESSAGE);
return ave[index];
class mainmenu{
public static void main(String[] args) {
int i=0;
int rep=0;
int numba;
String temp="";
int[] anArray;
anArray = new int[10];
methodmin fmin = new methodmin();
methodmax fmax = new methodmax();
methodsum fsum = new methodsum();
methodave fave = new methodave();
JOptionPane.showMessageDialog(null,"This is a program that will \n"
+ "display the Minimum, Maximum, \n"
+ "Sum and Average numbers in a \n"
+ "Single Dimension Array \n"
+ "Using Objects and Classes"
,"Single Dimension Array"
,JOptionPane.INFORMATION_MESSAGE);
do{
for(i=0; i<=9; i++)
anArray=Integer.parseInt(JOptionPane.showInputDialog (null,"Enter ten numbers"
,"Single Dimension Array"
, JOptionPane.QUESTION_MESSAGE));
numba = anArray[0];
for(i=0; i<=9; i++)
numba = anArray[i];
temp=temp+"\n"+numba;
JOptionPane.showMessageDialog(null,"The Numbers Entered Are: " + temp
+ "\n"
,"Single Dimension Array"
,JOptionPane.INFORMATION_MESSAGE);
fmin.makemin(anArray);
fmax.makemax (anArray);
fsum.makesum(anArray);
fave.makeave(anArray);
rep = JOptionPane.showConfirmDialog (null,"Input another number?"
,"Single Dimension Array"
,JOptionPane.YES_NO_OPTION);
while(rep==0);
JOptionPane.showMessageDialog(null,"Reading Arrays"+"\n Programmed by: Carl Anthony P. Estepa"
,"Single Dimension Array"
, JOptionPane.INFORMATION_MESSAGE); -
how can i khnow the blockdiagram for each function in labview like the function Add Array Element,
tinamoli wrote:
in my vi ihave an array of n_elements,,and i want to subtract each element by the first element,,
in the function i could find add array elements,,which if i know its block diagram ,maybe i can mimicking it for subtraction,,
Why don't we keep all this in one place? Thanks!
(And no, "add array elements" has really nothing to do with what you need. It will just give a single number that is the sum of all array elements, while you need to operate element by element.)
LabVIEW Champion . Do more with less code and in less time . -
How do i draw a graph in a applet from ny data
Hi, again sorry to keep coming back to you guys, but i have been trying hard to attempt things myself.I have read loads of books and can not find example to work from.I have managed with your "help" to finnish my calculations. Now i need to plot a graph with the data from my X array and Y array. I will then try my self to plot the linear least fit line if it kills me. I would like to print stars on the graph using the points in my arrays. But where do i start
sorry if i am asking to much i will understand if you can't help as you have really good programers asking proper questions instead of a novice like me.i have tried but get errors
LinearLeast1.java:111: illegal start of expression
public void paint (Graphics gr)
^
LinearLeast1.java:120: ';' expected
^
LinearLeast1.java:3: cannot resolve symbol
symbol : class Applet
location: class LinearLeast1
class LinearLeast1 extends Applet
^
3 errors
lindsey
code:
import java.io.*;
class LinearLeast1 extends Applet
{ // start of new class
//defines the sum method
public static double SumA (double arr[])
double SumA =0; //sum of array
if (arr.length >=1)
for(int i=0; i< arr.length; i++)
SumA +=arr;
else
SumA =0; // insuficient data
return SumA;
// defines the sum of XY array method
public static double sumXY (double arrX[],double arrY[])
double SumXY=0; // sum of arrays X*Y
if(arrX.length>=2)
for(int i=0; i< arrX.length;i++)
SumXY +=arrX[i]*arrY[i];
else
SumXY=0;//insufficient data
return SumXY;
//defines the avarage method
public static double AverageB (double arr[])
double SumA =0; //sum of array
double AverageB =0; // average of array
if (arr.length >=1)
for(int i=0; i< arr.length; i++)
SumA +=arr[i];
AverageB = SumA / arr.length;
else
AverageB =0; // insuficient data
return AverageB;
//defines array to the power of 2 method
public static double SumB (double arr[])
double SumB = 0; // sum of squares of array
double SumA =0; //sum of array
double Square =0; // array to the power of 2
if (arr.length >=2)
for(int i=0; i< arr.length; i++)
SumA +=arr[i];
SumB += arr[i] * arr[i];
Square =Math.sqrt((arr.length* SumB - SumA*SumA) / (arr.length*(arr.length-1)));
else
Square =0; // insuficient data
return SumB;
public static void main(String[]args)
{ //start of main method
//values for array x
double [] arrX ={-4.91,-3.84,-2.41,-2.62,-3.78,-0.52,-1.83,-2.01,0.28,1.08,
-0.94,0.59,0.69,3.04,1.01,3.60,4.53,5.13,4.43,4.12};
// values for array y
double [] arrY ={-8.18,-7.49,-7.11,-6.15,-5.62,-3.30,-2.05,-2.83,-1.16,0.52,
0.21,1.73,3.96,4.26,5.75,6.67,7.70,7.31,9.05,10.05};
double SumXY = sumXY(arrX,arrY);
double m = (SumXY-(SumA(arrX)*AverageB(arrY)))/ (SumB(arrX)-(SumA(arrX)*AverageB(arrX)));
double B = LinearLeast1.AverageB(arrY)-m*LinearLeast1.AverageB(arrX);
// System.out.println(" m = "+ m );
// System.out.println(" array X * array Y = "+LinearLeast1.sumXY(arrX,arrY));
// System.out.println(" sum ofarray x "+ LinearLeast1.SumA(arrX));
// System.out.println(" sum ofarray y "+ LinearLeast1.SumA(arrY));
// System.out.println(" avarage of array x " + LinearLeast1.AverageB(arrX));
// System.out.println(" avarage of array y " + LinearLeast1.AverageB(arrY));
// System.out.println(" power of 2 array x " + LinearLeast1.SumB(arrX));
// System.out.println(" m= "+m);
// System.out.println(" B= "+B);
public void paint (Graphics gr)
for(int i=1; i< arr.length; i++)
g.drawLine((i-1)*arrXSCALING, arr[i-1]*YSCALING,
i*XSCALING, arr[i]*YSCALING);
}//end of paint method
} //end of main method
} // end of classThanks for that, I thought I upset every one, only just stopped crying
here is my ammended code again before I go to bed, hope it's right this time
import java.io.*;
class LinearLeast1 extends Applet
{ // start of new class
//defines the sum method
public static double SumA (double arr[])
double SumA =0; //sum of array
if (arr.length >=1)
for(int K=0; K< arr.length; K++)
SumA +=arr[K];
else
SumA =0; // insuficient data
return SumA;
// defines the sum of XY array method
public static double sumXY (double arrX[],double arrY[])
double SumXY=0; // sum of arrays X*Y
if(arrX.length>=2)
for(int K=0; K< arrX.length;K++)
SumXY +=arrX[K]*arrY[K];
else
SumXY=0;//insufficient data
return SumXY;
//defines the avarage method
public static double AverageB (double arr[])
double SumA =0; //sum of array
double AverageB =0; // average of array
if (arr.length >=1)
for(int K=0; K< arr.length; K++)
SumA +=arr[K];
AverageB = SumA / arr.length;
else
AverageB =0; // insuficient data
return AverageB;
//defines array to the power of 2 method
public static double SumB (double arr[])
double SumB = 0; // sum of squares of array
double SumA =0; //sum of array
double Square =0; // array to the power of 2
if (arr.length >=2)
for(int K=0; K< arr.length; K++)
SumA +=arr[K];
SumB += arr[K] * arr[K];
Square =Math.sqrt((arr.length* SumB - SumA*SumA) / (arr.length*(arr.length-1)));
else
Square =0; // insuficient data
return SumB;
public static void main(String[]args)
{ //start of main method
//values for array x
double [] arrX ={-4.91,-3.84,-2.41,-2.62,-3.78,-0.52,-1.83,-2.01,0.28,1.08,
-0.94,0.59,0.69,3.04,1.01,3.60,4.53,5.13,4.43,4.12};
// values for array y
double [] arrY ={-8.18,-7.49,-7.11,-6.15,-5.62,-3.30,-2.05,-2.83,-1.16,0.52,
0.21,1.73,3.96,4.26,5.75,6.67,7.70,7.31,9.05,10.05};
double SumXY = sumXY(arrX,arrY);
double m = (SumXY-(SumA(arrX)*AverageB(arrY)))/ (SumB(arrX)-(SumA(arrX)*AverageB(arrX)));
double B = LinearLeast1.AverageB(arrY)-m*LinearLeast1.AverageB(arrX);
public void paint (Graphics gr)
for(int K=1; K< arr.length; K++)
g.drawLine((K-1)*arrXSCALING, arr[K-1]*YSCALING,
K*XSCALING, arr[K]*YSCALING);
}//end of paint method
} //end of main method
} // end of classHope that is better, I will take your advise and not give up. Will try to have another go tomorrow as it is 2.30am now. So I will try and get some sleep. Thanks again for coming back to answer I needed that bit of encouragement. Don't know if that bit of code for drawing my applet is right or not.
good night and thanks again
Lindsey -
Something is wrong with my subTotal script
The script actually works fine until you skip a line in the the form. Then the amount from that line is appended to the end of the Subtotal. For example: If the Price.0 field is $100.00 and the Price.1 field is $100.00, the Subtotal field shows $200.00. So far so good. Now if Price.3 is skipped and $50.00 is entered in Price.4, the Subtotal field shows $20,050.00.
Here's the script:
var subTotal = this.getField("Price.0").value
+ this.getField("Price.1").value
+ this.getField("Price.2").value
+ this.getField("Price.3").value
+ this.getField("Price.4").value
+ this.getField("Price.5").value
+ this.getField("Price.6").value
event.value = subTotal;The "+" operator is used for an arithmetic addition or string concatenation and JavaScript looks at the 2 values involved and assumes what operation is being asked for. It the values are 2 numbers addition is assumed, if 2 character strings then concatenation is assumed, and if one value is a number and the other a character string concatenation is assumed. You need to use the "Number()" constrictor to force the calculation to use an arithmetic addition.
Your script can be simplified by using some document level function to sum an array of fields.
// document level function
function SumArray(aValues) {
var sum = 0; // sum
// loop through array of values
for(i = 0; i < aValues.length; i++) {
sum += Number(aValues[i]);
} // add element i to sum
return sum; // return sum
} // end function
function MakeAValues(sFieldName) {
var oField = this.getField(sFieldName); // get field object
var aFields = oField.getArray(); // convert field object to an array of fields
var aValues = new Array(aFields.length); // array for the values of the fields
for(j = 0; j < aFields.length; j++) {
aValues[j] = aFields[j].value;
} // end for loop
return aValues; // pass back array of values
// end of document level functions
// custom calculation script to sum a hierarchical group of fields
// use defined function to:
// create an array of values
// sum that array of values
event.value = SumArray( MakeAValues("Price") );
You could also use this undocumented funcition:
AFSimple_Calculate("SUM", "Price");
But it will hide the script. -
Using quadrature encoders with PXI-6025
Hi!,
We are using an encoder for position data. The encoder gives A and B pulses which are phase shifted by 90 deg.
Grating Pitch = 40 microns
We make the connection to our PXI-6025 as such:
Channel A pulse goes to PFI 8 (GPCTR_Source)
Channel B pulse goes to DIO6 (GP_Up_Down)
Ground goes to DGND
We are able to increment/decrement the counter on our 6025 for every 40 micron movement
However, we are unable to quad the input and increment/decrement for every 10 microns. How do we achieve this?
We have an electronic circuit which converts the 40 micron A and B pulse from the encoder into 4 pulses spaced at 10 microns. But, using this single pulse mode does not allow for up/down counting.
We are using LV-7.1
, NI-DAQ 7.2 and Win2000 prof.
Looking forward to some quick help.
Thanks,
Gurdas
Gurdas Singh
PhD. Candidate | Civil Engineering | NCSU.eduThere's one tedious way that might work if you only need to post-process the data. However there are several possible problems.
The idea is to perform buffered semi-period measurements with both the counters on the 6025. Once you've collected all the needed semi-period data, perform a cumulative sum of each array so you end up with timestamps for all the transitions. Then you'll need to go through them to distinguish (+) from (-) direction quadrature transitions and generate a cumulative position array.
I don't think there's another way -- only semiperiod measurements will react to both edges of an incoming pulse train. However, it *is* possible in principle to get your 4x factor in resolution. Now for the problem list:
1. Your 6025E only has 1 DMA channel. One of the counters will have to be configured to use interrupts, which in turn will limit the maximum encoder rate you can track. I wouldn't count on tracking better than single digits of kHz, and you may not even be able to achieve that much.
2. The last time I did semiperiods on an E-series board, there was no way to specify which edge would mark the first recognized transition. If the input was low when you started, the first transition recorded would be a rising edge; if high, then a falling edge.
Knowledge of the initial state of the inputs is critical for your software quadrature decoding. I think the solution I used was to parallel wire the A&B channels to a couple DIO pins which I inspected before any encoder motion started. If your encoder jitters or vibrates about its nominal position however, you're probably hosed.
Are you sure you can't use the LS7084 to replace your other external circuit? The alternatives are either going to be trouble-prone gimmicks like I described above or the purchase of new DAQ equipment.
If you have budget for new DAQ equipment from NI, I'd suggest you look into one of the following:
1. Low-cost M series multi-function board
These have 2 32-bit counters onboard that are capable of quadrature decode. Each counter gets its own DMA channel for buffered acquisition. Plus you get a bunch of analog in, timed digital i/o, and can get analog outs. The boards are $475 with 2 analog outputs, $375 with none.
2. dedicated counter/timer board
The 6601 is cheaper at $295, but is limited to 1 DMA channel and has a slower onboard timing clock. The 6602 costs about double that but gives you somewhat more than double capability.
-Kevin P. -
Hi,
I am trying to make a simple code where a main program calls a method in a class so that the total sum of all elements of an array is calculated. Here is my code:
public class playingwithArrays
static void sumArray(int [] arr){
int sum = 0;
for(int i = 0; i<arr.length; i++){
sum+= arr;
System.out.println ("Total sum of array is" + sum);
This is the class where there is the method i want to access
The class below is the main class:public class Start
public static void main (STring[] args){
int [] arr = new int [10];
for (int i; i<arr.length; i++){
arr[i] = (i+1);
playingwithArrays summation = new playingwithArrays ();
summation.sumArray(int arr[]);
Where there is bold the compiler is giving me a .class error. Please can you help me as I am a beginner and I am trying to learn java!It's a good idea to follow standard conventions about nAmEs. PlayingWithArrays, not playingwithArrays.
You define sumArray() as a static method. That means that it will not be associated with a particular instance of the PlayingWithArrays class. And so you can access it without having to create a new instance of the class.
It's not actually wrong to say summation.sumArray(...), it's just that it looks odd. It would better be PlayingWithArrays.sumArray(...).
The actual error is what you are passing as the argument. This method expects an array of int and that's what you should pass it. You don't need the int and [] business that goes into the declaration of a method, just use the variable.
PlayingWithArrays.sumArray(arr);This will use a static method of the PlayingWithArrays class to print out the sum of the array elements. -
Problems with a while loop within a method... (please help so I can sleep)
Crud, I keep getting the wrong outputs for the reverseArray. I keep getting "9 7 5 7 9" instead of "9 7 5 3 1". Can you guys figure it out? T.I.A (been trying to figure this prog out for quite some time now)
* AWT Sample application
* @author Weili Guan
* @version 1999999999.2541a 04/02/26
public class ArrayMethods{
private static int counter, counter2, ndx, checker, sum, a, size, zero;
private static int length;
private static int [] output2, output3, reverse, array;
private static double output;
private static double dblsum, dblchecker, average;
public static void main(String[] args) {
//int
//int [] reverse;
System.out.println("Testing with array with the values [1,3,5,7,9]");
size = 5;
array = new int [size];
reverse = new int [size];
array[0] = 1;
array[1] = 3;
array[2] = 5;
array[3] = 7;
array[4] = 9;
System.out.println("Testing with sumArray...");
output = sumArray(array);
System.out.println("Sum of the array: " + sum);
System.out.println();
System.out.println("Testing with countArray...");
output = countArray(array);
System.out.println("Sum of the elements : " + checker);
System.out.println();
System.out.println("Testing with averageArray...");
output = averageArray(array);
System.out.println("The average of the array : " + average);
System.out.println();
System.out.println("Testing with reverseArray...");
output2 = reverseArray(array);
output3 = reverseArray(reverse);
//System.out.print(reverse[4]);
System.out.print("The reverse of the array : ");
for(ndx = 0; ndx < array.length; ndx++){
System.out.print(reverse[ndx] + " ");
private ArrayMethods(){
public static int sumArray(int[] array){
checker = 0;
ndx = 0;
counter = 0;
sum = 0;
while(counter < array.length){
if (array[ndx] > 0){
checker++;
counter++;
if(array.length > 0 && checker == array.length){
while(ndx < array.length){
sum += array[ndx];
ndx++;
return sum;
else{
sum = 0;
return sum;
/*Computes the sum of the elements of an int array. A null input, or a
zero-length array are summed to zero.
Parameters:
array - an array of ints to be summed.
Returns:
The sum of the elements.*/
public static int countArray(int[] array){
checker = 0;
ndx = 0;
counter = 0;
sum = 0;
while(counter < array.length){
if(array[ndx] > 0 && array[ndx] != 0){
checker++;
counter++;
return checker;
/*Computes the count of elements in an int array. The count of a
null reference is taken to be zero.
Parameters:
array - an array of ints to be counted.
Returns:
The count of the elements.*/
public static double averageArray(int[] array){
dblchecker = 0;
ndx = 0;
counter = 0;
dblsum = 0;
while(counter < array.length){
if(array[ndx] > 0){
dblchecker++;
counter++;
if(array.length > 0 && checker == array.length){
while(ndx < array.length){
dblsum += array[ndx];
ndx++;
average = dblsum / dblchecker;
return (int) average;
else{
average = 0;
return average;
/*Computes the average of the elements of an int array. A null input,
or a zero-length array are averaged to zero.
Parameters:
array - an array of ints to be averaged.
Returns:
The average of the elements.*/
public static int[] reverseArray(int[] array){
ndx = 0;
counter = 0;
counter2 = 0;
if(array.length == 0){
array[0] = 0;
return array;
else{
//reverse = array;
while(ndx <= size - 1){
reverse[ndx] = array[4 - counter];
counter++;
ndx++;
System.out.print("H ");
return reverse;
/*Returns a new array with the same elements as the input array, but
in reversed order. In the event the input is a null reference, a
null reference is returned. In the event the input is a zero-length array,
the same reference is returned, rather than a new one.
Parameters:
array - an array of ints to be reversed.
Returns:
A reference to the new array.*/
}What was the original question? I thought it was
getting the desired output, " 9 7 5 3 1."
He didn't ask for improving the while loop or the
reverseArray method, did he?
By removing "output3 = reverseArray(reverse):," you
get the desired output.Okay, cranky-pants. Your solution provides the OP with the desired output. However, it only addresses the symptom rather than the underlying problem. If you'd bother yourself to look at the overall design, you might see that hard-coding magic numbers and returning static arrays as the result of reversing an array passed as an argument probably isn't such a great idea. That's why I attempted to help by providing a complete, working example of a method that "reverses" an int[].
Removing everything and providing "System.out.println("9 7 5 3 1");" gets him the desired output as well, but (like your solution) does nothing to address the logic problems inherent in the method itself and the class as a whole. -
Hello,
I wrote a multichannel data acquisition code including Respiration ,ECG and GSR (Galvanic Skin Response). I want to calculate beat per minute and breathing rate. I�ve used a threshold peak detector. I�ve thought that the difference of the index of the first peak and th index of the second peak generates the number of total samples between two consecutive counts. To count the beat rate per second I divided sample rate by the number of samples per beat. Then I�ve multiplied beat rate per second by 60 to generate beat rate per minute. I also did the same thing for breath rate per minute.
The problem is the result wasn�t successful. As you can see in the attachment I�ve calculated bpm as 253 and brpm is 538. BPM should be
60 for a healthy person and BRPM should be 15.
Ther is nothing wrong with my signals. But as you can see in the diagram data comes as #4 and difference between index of the first peak and the index of the second peak is quite high.
What do you recommend me to do to calculate the correct values.
Thanks
Attachments:
multichannel.JPG 89 KB
diagram.JPG 100 KBHave a look on the attached vi.
The first loop runs in 1 second, generating an array of 100 random numbers;
The second loop calculates the sum of the array elements, and would run every 0.2 seconds.
Except that the occurence nodes synchronize the calculation with the availability of the data array.
You can experiment the effect of occurence by removing the nodes : the vi still runs, but the led blinks 5 times more rapidly.
Last comment : don't forget the ultimate set occurence when exciting the first loop, otherwise the second loop will wait for ever...
Ask if you need more help.
CC
Chilly Charly (aka CC)
E-List Master - Kudos glutton - Press the yellow button on the left...
Attachments:
Synchro_loops.vi.zip 13 KB
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