java convert Object to double array

Question

I have a piece of code that returns an Object array. Each slice of the array then contains data that was initially a two dimensional array of doubles. I can't change this piece of code as it's part a Matlab thing (see link below).

http://www.mathworks.com/help/mps/java/code-multiple-outputs-for-java-client.html

My question is how do I convert each slice of the Object[] back into a double[][] within Java?

Here's some sample code

Object[] test = getDailyLog(1,20050101,20060101);
Object a = test[1];
System.out.println(a);

From this I get the output

[[D@17b90c55

It's unclear from your description what sort of objects are actually in the array. You need to change your code snippet above to do System.out.println(a.getClass().getName());, to show the class of the objects. Then one can figure out how to extract the values. — Hot Licks
– Hot Licks, Commented Jul 31, 2014 at 2:01
(But the [[ prefix above suggests you have a two-dimensional array, and maybe the D means double (been a long time since I've looked at the default toString for an array).) — Hot Licks
– Hot Licks, Commented Jul 31, 2014 at 2:03

jawee · Accepted Answer · 2014-07-31 02:01:21Z

1

From your description, it could be inferred that 'test' is an array of "double[][]". Therefore, you could use the coersion cast to fulfil your requirement, example is listed as below:

        Object[] test = getDailyLog(1,20050101,20060101);

        double[][] d2d;
        for(Object obj : test) {
            d2d = (double[][]) obj;
        }

answered Jul 31, 2014 at 2:01

jawee

2712 silver badges11 bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

Hot Licks Over a year ago

Of course, that would extract all the elements into one array, writing one on top of the next. You really should extract into a 3-dimensional array.

Kevin Krumwiede Over a year ago

More correctly, it would refer to each element using the same reference.

jhlu87 Over a year ago

I changed it so that each Object gets it's own double array variable. Thanks!

Collectives™ on Stack Overflow

java convert Object to double array

1 Answer 1

3 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

3 Comments

Your Answer

Sign up or log in

Post as a guest

Related