将字符串数组转换为多维double

Question

I need to read a matrix from a file in to double[,]. Till now it is possible to read the file as a string[]. The datastructure looks like that:

But the conversion doesn't work.

I already tried a lot of stackoverflow articles, but it failed always with "Input string was not in a correct format". Important is that the values are all double values and seperated with three spaces.

I read the file like this:

var text = File.ReadAllLines(@"right.txt");

Answer 1

You can do this several ways, and it depends if you want a jagged array, or a multidimensional array.

There are probably more succinct ways of doing this, however, you can see the idea.

Jagged

var jaggedArray = File.ReadAllLines(@"d:\right.txt")
                        .Where(x => !string.IsNullOrWhiteSpace(x))
                        .Select(x => x.Split(new[]{' '},StringSplitOptions.RemoveEmptyEntries)
                                     .Select(double.Parse)
                                     .ToArray())
                        .ToArray();

Multidimensional

var lines = File.ReadAllLines(@"d:\right.txt")
                  .Where(x => !string.IsNullOrWhiteSpace(x))
                  .Select(x => x.Split(new[]{' '},StringSplitOptions.RemoveEmptyEntries)
                               .Select(double.Parse)
                               .ToList())
                  .ToList();

var h = lines.Count();
var w = lines.Max(x => x.Count);
var multiArray = new double[h, w];

for (var i = 0; i < lines.Count; i++)
   for (var j = 0; j < lines[i].Count; j++)
      multiArray[i, j] = lines[i][j];

_{Note : Totally untested, and I am not responsible for the people maim or otherwise harm with this code
Note 2 : There is no error checking or fault tolerance, if there is garbage in your file, this will likely throw}

Update

Is there a way to debug/fix that? Maybe the problem is that the double values are separated with 3 spaces and not only 1 space? Is there a way to fix this in a LINQ statement?

Yes if there are multiple spaces using StringSplitOptions.RemoveEmptyEntries should work

Split(new [] {' '},StringSplitOptions.RemoveEmptyEntries)

However note, this really assumes, that every separated value can be converted to a double , and there is no blank lines (even at the end of the file)

You can solve the blank line problem by using something like this included in the linq statement

File.ReadAllLines(@"right.txt")
    .Where(x => !string.IsNullOrWhiteSpace(x))
    ...