Write a function that takes 3 10x10 arrays as arguments. Store the matrix product of the first two arguments in the 3rd argument.

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Oregon1979

Write a function that takes 3 10x10 arrays as arguments. Store the matrix product of the first two arguments in the 3rd argument.

in General Discussion • Other • 9 months ago

I just need somebody or people to guide me in starting this whole thing. One thing I'm not sure of, and am drawing a blank, is when it says take them as arguments and everything else. Any help would be nice. Get me in the right direction.

Replies(4)

asimes

Re: Write a function that takes 3 10x10 arrays as arguments. Store the matrix product of the first two arguments in the 3rd argument.

9 months ago

I would recommend having a function that takes two arrays as an argument and returns an array that is the resulting Matrix multiplication. I'm going to assume that your Matrices are storing floats. Personally I prefer representing Matrices as a normal array but some people prefer double arrays. Here is a basic setup for either case (determine which representation you want to use and discard the other code):

float[] matrixA1, matrixB1;
float[][] matrixA2, matrixB2;
void setup() {
size(100, 100);
// If you want to use normal arrays use these
matrixA1 = new float[100];
matrixB1 = new float[100];
float[] matrixC1 = matrixMult1(matrixA1, matrixB1);
// If you want to use double arrays use these
matrixA2 = new float[10][10];
matrixB2 = new float[10][10];
float[][] matrixC2 = matrixMult2(matrixA2, matrixB2);
}
void draw() {
}
float[] matrixMult1(float[] a, float[] b) {
float[] out = new float[100]; // 100 is 10x10
// Matrix multiplication code here
return out;
}
float[][] matrixMult2(float[][] a, float[][] b) {
float[][] out = new float[10][10];
// Matrix multiplication code here
return out;
}

Edit: I just noticed that you posted this question twice, don't do that. I probably should have answered the one under Programming Questions instead but I'm going to delete that one.

Edit (again): Topic moved to Programming Questions

Oregon1979

Re: Write a function that takes 3 10x10 arrays as arguments. Store the matrix product of the first two arguments in the 3rd argument.

9 months ago

What is draw()?

asimes

Re: Write a function that takes 3 10x10 arrays as arguments. Store the matrix product of the first two arguments in the 3rd argument.

9 months ago

That is the main loop in Processing... setup() is called (automatically) when the Program starts and draw() runs continuously after. I tend to write draw() so that the program can be closed by pressing escape when it is running (this doesn't work without the draw() loop).

Edit: By main loop I mean generally where people put code in Processing, not main like in C++

GoToLoop

Re: Write a function that takes 3 10x10 arrays as arguments. Store the matrix product of the first two arguments in the 3rd argument.

9 months ago

I tend to write draw() so that the program can be closed by pressing escape when it is running (this doesn't work without the draw() loop).

If a program of mine doesn't use callback function draw() , I just include noLoop() inside setup() .

Thus, no need for an empty draw() {} !
Other times, when I just need to check what is printed at the console box, I outright use exit() instead.

A mindless example:

void setup(){
    noLoop();
    line(10,10,80,80);
}

println( 1024>>8 );
exit();

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