Converting a Multidimentional Array

Thread view:

Enable EMail Alerts

Start New Thread

Thread rating:

AMP - 28 Mar 2008 17:34 GMT

Hello,
I am trying to convert MD array of ints to doubles;
I just want each x to be converted.
I am getting a Nullexception.
I was able to do this with a single dimention, but I am having
problems here.
OurData is passed correctly but GraphData looks like one dimention
when I get to Line commented with an error

public double[][] GraphData;
public Form3(int[][] OurData)
{
GraphData = new double[OurData.Length][];
for (int y=1;y<OurData.Length;y++)
{
foreach (int x in OurData[y])
{
GraphData[y][x] = System.Convert.ToDouble(x); //
ERROR
}

InitializeComponent();
}
}

Thanks for your help
Mike

Reply to this Message

Family Tree Mike - 28 Mar 2008 17:57 GMT

Notice that your inner loop is using the value of the array as the index into
it. I believe your inner loop should be a more traditional loop, as in for
(int idx = 0; idx < ourdata [y].length; ++idx). Also, your outer loop
"probably" is supposed to start at zero, but that is your choice.

> Hello,
> I am trying to convert MD array of ints to doubles;
[quoted text clipped - 23 lines]
> Thanks for your help
> Mike

Reply to this Message

NvrBst - 28 Mar 2008 19:03 GMT

On Mar 28, 9:57 am, Family Tree Mike
<FamilyTreeM...@discussions.microsoft.com> wrote:

> Notice that your inner loop is using the value of the array as the index into
> it. I believe your inner loop should be a more traditional loop, as in for
[quoted text clipped - 30 lines]
>
> - Show quoted text -

FTM is correct, its usally, conceptually, easier to use traditional
loops, in this case. The reasion your code gives a null error
reference is because you never allocate the inner "double[]" (will
need two "new" keywords in your code for a double[][]). To conver a
int[][] to double[][] you can do something like the following.

-------------------
int[][] OurData = { new int[] { 5, 3, 1 }, new int[]
{ 3 }, new int[] { 1, 2, 3, 4, 5 } };
double[][] GraphData = new double[OurData.Length][];

for(int i = 0; i < OurData.Length; i++) {
GraphData[i] = new double[OurData[i].Length];
for(int ii = 0; ii < OurData[i].Length; ii++)
GraphData[i][ii] = (double)OurData[i][ii];
}
-------------------

Alternativly, if you like foreach loops, you can do it the same way
you would a while loop (with manual counters - UntestedCode);
-------------------
int oCounter = 0, iCounter = 0;
foreach(int[] A in GraphData) {
GraphData[oCounter++] = new
double[OurData[oCounter]].Length];
foreach(int B in A) GraphData[oCounter][iCounter++] =
(double)B;
iCounter = 0;
}
-------------------

Cheers, NB

Reply to this Message

Rate this thread:

Converting a Multidimentional Array

Free Magazines