I am relative new to java and i need help to use matrix with async Task.
I am using input frame from onCameraFrame to analysis in background.
I will provide the method and async Task.
public int recognize(Mat inputFrame) {
int detector=0;
Mat gray= inputFrame;
if (startedFrame){
BRISK.detect(inputFrame,keypoints1);
BRISK.compute(inputFrame,keypoints1,deskriptor1);
startedFrame=false;
return 0;
}
BRISK.detect(inputFrame,keypoints2);
BRISK.compute(inputFrame,keypoints2,deskriptor2);
List<MatOfDMatch> matches = new LinkedList<MatOfDMatch>();
matcher.knnMatch(deskriptor1, deskriptor2, matches,2);
//Calculating good match list...
LinkedList<DMatch> goodMatchesList = new LinkedList<DMatch>();
for (int i = 0; i < matches.size(); i++) {
MatOfDMatch matofDMatch = matches.get(i);
DMatch[] dmatcharray = matofDMatch.toArray();
DMatch m1 = dmatcharray[0];
DMatch m2 = dmatcharray[1];
if (m1.distance <= m2.distance * nndrRatio) {
goodMatchesList.addLast(m1);
}
}
if (goodMatchesList.size() >= 7) {
List<KeyPoint> controlKeypointlist = keypoints1.toList();
List<KeyPoint> liveKeypointlist = keypoints2.toList();
LinkedList<Point> objectPoints = new LinkedList<>();
LinkedList<Point> scenePoints = new LinkedList<>();
for (int i = 0; i < goodMatchesList.size(); i++) {
objectPoints.addLast(controlKeypointlist.get(goodMatchesList.get(i).queryIdx).pt);
scenePoints.addLast(liveKeypointlist.get(goodMatchesList.get(i).trainIdx).pt);
}
MatOfPoint2f objMatOfPoint2f = new MatOfPoint2f();
objMatOfPoint2f.fromList(objectPoints);
MatOfPoint2f scnMatOfPoint2f = new MatOfPoint2f();
scnMatOfPoint2f.fromList(scenePoints);
detector=1;
keypoints2.release();
deskriptor2.release();
return 2;
}
return 1;
}
class MyTask extends AsyncTask<Mat, Void, Integer> {
#Override
protected Integer doInBackground(Mat... mats) {
return recognize(mats);
}
}
And problem is in return recognize(mats);,in parametar matswhere it say:recognize (org.opencv.core.Mat) in MainActivity cannot be applied
to (org.opencv.core.Mat[]) and i do not know how to solve it?Thanks in advance.
The parameter Mat... is a varargs parameter and acts like an array. (i.e. Mat[]).
To get the first Mat of the arguments use mats[0]:
#Override
protected Integer doInBackground(Mat... mats) {
return recognize(mats[0]);
}
In Java Mat... represents an array of Mat class type. If you look at the error
recognize (org.opencv.core.Mat) in MainActivity cannot be applied to (org.opencv.core.Mat[])
You'll notice that it says exactly the same thing i.e. you are passing an Array to a method which takes a single instance. So all you need to do is:
return recognize(mats[0]);
get the Mat at the first index of this array.
Related
Lets say I have a public class called GameBoard that will be a two dimensional array with 4 rows and 5 columns. The spaces in the array are filed with String values from 1 to 20. A card will be drawn that has a name (King of Spades for example) . If the user inputs 15 I will store it in a String variable called userLocation. What would be the most efficient way to create a method that takes the input location and updates the array with the name of the Card? Would a for loop be most efficient?
public GameBoard() {
square = new String[4][5];
square[0][0] = new String("1");
square[0][1] = new String("2");
square[0][2] = new String("3");
square[0][3] = new String("4");
square[0][4] = new String("5");
square[1][0] = new String("6");
square[1][1] = new String("7");
square[1][2] = new String("8");
square[1][3] = new String("9");
square[1][4] = new String("10");
square[2][1] = new String("11");
square[2][2] = new String("12");
square[2][3] = new String("13");
square[3][1] = new String("14");
square[3][2] = new String("15");
square[3][3] = new String("16");
square[2][0] = new String(17);
square[3][0] = new String(18);
square[2][4] = new String(19);
square[3][4] = new String(20);
}
My preferred method as of now would look something like this but it gives me the error code "type mismatch:cannot convert string to boolean" under userLocation = board[i][j]
public String[][] updateBoard(String userLocation, Card card, String[][] board) {
for (int i = 0; i <4; i++)
{
for (int j = 0; j < 5; j++)
{
if(userLocation = board[i][j]) {
board[i][j] = card.name;
}
}
}
return board;
}
So the reason it will not compile is your = does not return a boolean expression. == would, but it's still not what you want, since you want to check if the String contents are the same, not if they're the same object, so use .equals.
But, no, I think you don't want to depend on strings to identify locations. What if you want to replace a card? And why look through everything when you need not?
Rather if i is some number between 1 and 20, identify the corresponding spot in the array by square[(i-1)/5][(i-1)%5]
That should bypass the issue you are having with matching strings.
So for example, your constructor becomes:
public GameBoard() {
square = new String[4][5];
for (int i=1; i<=20;i++){
square[(i-1)/5][(i-1)%5]=""+i;//initialize with 1 to 20 if you like
}
and userLocation is an int.
I have two classes: class Creature which contains ArrayList boids, and class Food.
Boids have a few parameters:
Creature(float posX, float posY, int t, int bth, int ah) {
location = new PVector(posX, posY);
vel = new PVector(random(-5,5), random(-5, 5));
acc = new PVector();
type = t;
if (t == 1) { btype = bth; }
else { health = bth; }
if (t == 1) { age = ah; }
else { hunger = ah; }
wdelta = 0.0;
action = 0;
if (btype == 1) { mass = 5.0; }
else { mass = 7.0; }
}
Food class has this method:
void foodtime(ArrayList boids) {
for (int i = 0; i < boids.size(); i++) {
Creature boid = (Creature) boids.get(i);
float distance = PVector.dist(location, boid.location);
if (distance < 0.5) {
bnumadj = i;
count++;
if (count == quantity) {
planet.food.remove(this);
count = 0;
bnumadj = -1;
}
}
}
}
What I'm trying to achieve is that if a boid "eats" the food, their boid type (btype) changes from 2 to 1.
I'm trying to use bnumadj variable to feed it back to the boid in this method:
void boid(ArrayList boids) {
for (int i = 0; i < boids.size(); i++) {
if (i == bnumadj) {
this.btype = 1;
bnumadj = -1;
}
}
}
Where am I going wrong?
This seems like a very convoluted way to do this, so I'm not surprised you're having issues. You're comparing values to indexes, which doesn't make a ton of sense to me.
Instead, try using a simple nested loop to do what you want. You can use an Iterator to make it easier to remove items while iterating.
ArrayList<Creature> boids = new ArrayList<Creature>();
ArrayList<Food> food = new ArrayList<Food>();
//populate ArrayLists
void draw(){
for(Creature boid : boids){
Iterator<Food> foodIter = food.iterator();
while(foodIter.hasNext()){
Food f = foodIter.next();
float distance = PVector.dist(boid.location, food.location);
if (distance < 0.5) {
boid.btype = 1;
foodIter.remove(); //removes the food
}
}
}
//draw the scene
}
I suppose you could move the second iteration using the Iterator inside the Creature type, but the basic idea is this: keep it simple by using an Iterator to remove the Food instead of trying to match indexes.
I have a project for school to take my current pacman program and have pacman traverse the 2-d char array to find a pattern to complete the maze.
I am trying to use a stack and add specific index of my maze to the stack so when pacman reaches the index it pops off and he chooses a direction randomly to another index and so forth until all dots are eaten. My issue is taking my 2d array and finding the index values of the intersections and then adding them to a stack.
I am new to java and not really sure how to approach this I posted my maze I have and some code that will use the stack to find the sequence. Thanks in advanced.
private void create() {
String[] tier = new String[tall];
tier[0] = "|======================================|";
tier[1] = "|......................................|";
tier[2] = "|.====.==========================.====.|";
tier[3] = "|.||||............................||||.|";
tier[4] = "|.====.==========================.====.|";
tier[5] = "|......................................|";
tier[6] = "|.====================================.|";
tier[7] = "|......................................|";
tier[8] = "|.====.======.====----====.======.====.|";
tier[9] = "|.||||........|| ||........||||.|";
tier[10] = "|.||||.======.|| ||.======.||||.|";
tier[11] = "|.||||........|| ||....... ||||.|";
tier[12] = "|.====.======.============.======.====.|";
tier[13] = "|......................................|";
tier[14] = "|.===========..............===========.|";
tier[15] = "|.............===== =====.............|";
tier[16] = "|.=======.===.||$ $||.===.=======.|";
tier[17] = "|.|||||||.===.===== =====.===.|||||||.|";
tier[18] = "|.|||||||......................|||||||.|";
tier[19] = "|.|||||||.====================.|||||||.|";
tier[20] = "|.=======......................=======.|";
tier[21] = "|.==......====================......==.|";
tier[22] = "|.==.====.======........======.====.==.|";
tier[23] = "|....====........======........====....|";
tier[24] = "|======================================|";
for (int i = 0; i < tall; i++) {
array[i] = tier[i].toCharArray();
}
}
public boolean isPattern(Spot b, Spot e) {
Stack<Spot> ss = new Stack<Spot>();
Spot topPost, nextPost;
allOld();
ss.push(b);
markOld(b);
topPost = ss.peek();
while (!ss.empty() && (topPost.compareTo(e) != 0)) {
nextPost = getNextSpot(topPost);
if (nextPost == null) {
ss.pop();
} else {
ss.push(nextPost);
markOld(nextPost);
}
topPost = ss.peek();
}
if (ss.empty()) {
return false;
} else {
return true;
}
}
public void index(int x, int y, int dx, int dy){
x=array.length;
y=array[x].length;
for( int i=0;i <x;i++){
for(int j =0; j<y;j++){
if(array[i].get(i))//this should determine if its aninersection and then add to the stack
}
}
}
}
the last method is where i am getting stuck. I dont know how to get the specific index values. I guess i can enter them manually but I am sure there is an easier way. Please comment if need more context on the problem and Thanks again.
I wrote a physical simulation about gravitational force between two planets.It worked perfectly fine so I decided to take it to a new level and rewrote it using arrays and five planets(circles).But my code gives strange and never the same error. I get either NullPointerException error or the VM error when intializing the sketch(No description just the "Vm error couldn't initialize skecth" and the "see help and troubleshoot" bullsh*t) The program uses a txt file to read in data(double-checked and it works fine).
My Array names and descriptions are
PVector - Pos stands for Position
PVector - Vel stands for Velocity
PVector - Acc stands for Acceleration
PVector - Dist stands for Distance
PVector - Dir stands for Direction
float - Mass stands for Mass
My code:
public PVector[] Pos = new PVector[5];
public PVector[] Acc = new PVector[5];
public PVector[] Vel = new PVector[5];
public PVector[] Dist = new PVector[5];
public PVector[] Dir = new PVector[5];
public float[] Mass = new float[5];
void setup(){
String Data[] = loadStrings("Data.txt");
size(800,800);
for(int g = 0;g < 5;g++){
Pos[g] = new PVector(float(Data[g+1]),float(Data[g+6]));
Vel[g] = new PVector(float(Data[g+12]),float(Data[g+17]));
Mass[g] = float(Data[g+23]);
}
}
void draw(){
for (int i = 0;i < 5;i++){
for (int f = 0;f < 5;f++){
if(i !=f){
if(Pos[i].x < Pos[f].x){Dir[f].x = 1;Dist[f].x = (Pos[f].x - Pos[i].x);}else{ // I get the error here
if(Pos[i].x > Pos[f].x){Dir[f].x = -1;Dist[f].x = (Pos[i].x - Pos[f].x);}else{
if(Pos[i].x == Pos[f].x){Dir[f].x = 0;Dist[f].x = 0;}}}
if(Pos[i].y < Pos[f].y){Dir[f].y = 1;Dist[f].y = (Pos[f].y - Pos[i].y);}else{
if(Pos[i].y > Pos[f].y){Dir[f].y = -1;Dist[f].y = (Pos[i].y - Pos[f].y);}else{
if(Pos[i].y == Pos[f].y){Dir[f].y = 0;Dist[f].y = 0;}}}
if ((Dist[f].x != 0)){
Acc[i].x+=((6*((Mass[i]*Mass[f])/Dist[f].magSq())/10000000)/Mass[i])*Dir[f].x;// *6/1000000 is MY G constant
}
if ((Dist[f].y != 0)){
Acc[i].y+=((6*((Mass[i]*Mass[f])/Dist[f].magSq())/10000000)/Mass[i])*Dir[f].y;
}
}
}
Vel[i].x = Vel[i].x + Acc[i].x;
Vel[i].y = Vel[i].y + Acc[i].y;
Pos[i].x = Pos[i].x + Vel[i].x;
Pos[i].y = Pos[i].y + Vel[i].y;
ellipse(Pos[i].x,Pos[i].y,10,10);
}
}
You create array of PVectors of size 5 here : public PVector[] Dir = new PVector[5]; . In this moment, it has null five times for indexes 0-4 in it.
Because you do not create new PVectors in this array, when you try to access variable x in here Dir[f].x, you got error, because Dir[f] is null and you cant access variable x of null -> NullPointerException.
In this part you are instantizing some arrays
for(int g = 0;g < 5;g++){
Pos[g] = new PVector(float(Data[g+1]),float(Data[g+6]));
Vel[g] = new PVector(float(Data[g+12]),float(Data[g+17]));
Mass[g] = float(Data[g+23]);
}
You should add instantizing also for Dir, Acc and Dist
Note also, that you are working with objects, not with primitive data types. null is not same as new PVector(0,0)
Also from "design" point of view, using arrays this way is NOT good approach. You should create your own class Planet, where each planet holds information about its properties and in your main class you handle interaction between them.
How to create "empty" or "zero" variables instead of nulls? Just create them :)
for(int g = 0;g < 5;g++){
Pos[g] = new PVector(float(Data[g+1]),float(Data[g+6]));
Vel[g] = new PVector(float(Data[g+12]),float(Data[g+17]));
Mass[g] = float(Data[g+23]);
Dir[g] = new PVector(0,0);
Acc[g] = new PVector(0,0);
Dist[g] = new PVector(0,0);
}
PS : I do not how exactly is this class implemented, using new PVector() or new PVector(0) instead of new PVector(0,0) may also work.
I've been issued the task of using MATLAB Builder to convert a MATLAB function into a Java class, now I have gotten to a point where I have the results from one class being fed into another and since the MATLAB builder will only output an object, I'm having issues.
import java.util.*;
import com.mathworks.toolbox.javabuilder.*;
public class mainKrigTau {
public static void main(String[] args) {
Object[] resultT = null;
Object[] resultK = null;
Object[] resultB = null;
krigingTau Tau = null;
krigingTau Krig = null;
Branin branin = null;
try {
Tau = new krigingTau();
Krig = new krigingTau();
branin = new Branin();
resultT = Tau.LPtau(1, 100, 2, 1234);
List<Object> X = Arrays.asList(resultT[0]);
System.out.println(X);
System.out.println((X.size()));
} catch (MWException e)
{
e.printStackTrace();
} finally
{
}
So basically the output of the Tau class is a 2D array, so the array is embedded into the resultT[] object, how to I get access to this array? One method I have tried is as above, changing it into an array list, X outputs the array, but I can't access the components of the array. X.size = 1, not 100 which is the actual size of the array. edit - just to add, all the examples I can find just output the result object and display it, rather than do anything with it.
Okay a software engineer nearby came to the rescue. It's a bit of a roundabout way but it works.
try {
Tau = new krigingTau();
Krig = new krigingTau();
branin = new Branin();
resultT = Tau.LPtau(1, 100, 2, 1234);
List<Object> X = Arrays.asList(resultT[0]);
if (X.get(0) instanceof MWNumericArray) {
MWNumericArray mw= (MWNumericArray) X.get(0);
ArrayList<Point> lists = new ArrayList<Point>();
for(int i = 1; i <= mw.numberOfElements()/2; i++){
Object o = mw.get(i);
System.out.println(o);
Double x = (Double) mw.get(i);
Double y = (Double) mw.get((mw.numberOfElements()/2)+i);
Point p = new Point(x.doubleValue(),y.doubleValue());
lists.add(p);
}
for(int i = 1; i < mw.numberOfElements()/2; i++)
{
resultB = branin.branin(1, lists.get(i).array);
System.out.println(resultB[0]);
}
where point sets the values of x and y into an array, so set it to an new MWNumericArray and do Object.get(i) but this flattens the array which is not ideal.