Cannot convert data from textfile to array using .Split (C# Unity3D)

Question

I have a (perhaps) simple question about reading a text file in Unity (C#) containing a matrix of floats, and converting it to a matrix (or multiple arrays) of floats. Before even getting there, I seem unable to succesfully convert the 'string'-typed text to an array using the .Split method.

To summarize, I need the weights of an artificial neural network, which are trained in MATLAB, in my Unity script to use for calculating outputs and performing certain actions.

I will show you carefully what I tried; First of all, the "WeightsIH.txt" file I intend to read looks like this:

-0.493654767886117  1.96685485682002
-0.493654767886117  1.96685485682002
-1.12167737625244   -0.835107290621868
-0.168882176970878  -0.0508678270221517
0.00848314746590752 0.645890421329432
-0.445148017062813  -0.647593931130814
0.0719861441229913  0.00251854104000363
-0.0809087627607675 -0.00253116474618752
0.0677112130287254  0.00229085080614581
0.0754386783608645  0.00239167974789985
0.0809669296303145  0.00253343860819182
-3.54887781611766   -0.884835613897628
-0.459886351851150  -0.848445431434901
-0.0670274486060166 -1.39397672397051
-3.82077442331056   -2.40290337409384
0.0783082838340459  0.00245132734091342
-0.239255503684809  -0.0118048053697862
-0.0798562101865881 -0.00249224979249840
-0.0639184016149756 -0.00224822783089479
-0.778070988555323  -0.872732391008980
0.0297507291420014  -1.74952458318966
0.0963966379119354  0.00416637970011285
0.875794416782941   0.513267873404847
0.0788049456605797  0.00246400296768071
-0.301882135742981  1.29009004735214
-0.427112778202037  -0.602081710823938
-0.0287160010856207 0.876736618413824
0.174484840994587   -0.914135602108887
-1.13771093704277   -1.80803211709460
-0.842897124110693  -0.491320433352398
-0.883862027266628  0.577867664170583
-0.00732465337711950    -0.0608133682721268
0.0808154577205481  0.00252756604265255
-0.623653482256716  0.802021714172196
0.354715179032082   -1.40951283673210
0.107130434979695   0.00718795362864938
-3.25429700675793   1.15179026184665
0.00323132998826740 0.725967105940923
-0.445271160376852  -0.634848835782688
0.0353267566953751  -0.761005808087746
0.343818927585420   0.181552084533698
1.52333372694938    -1.95500299702055
1.28692979700544    2.03963829780562
0.665570336193150   -0.410729910590931
-0.0861536175683719 -0.00286332759826070
0.126619076047933   0.0171533754647685
-0.0822566525595005 -0.00259193055392493
-1.28712374245194   1.12380947288866
-1.29253445353219   -2.05175940341935
0.416493102590467   -0.617909454448863
0.0969179981825367  0.182721981022912
-0.0808788394332979 -0.00252999992128388
0.925818615324062   -1.91710736361040
-0.438361270919922  0.0119396635243124
1.05250770533487    -0.965588245752274
-0.0480257526132498 -0.00154845733604858
-0.0586872685404968 -0.00184430469780941
-0.471992797137374  -0.672492593551730
0.439729645530884   1.55878656878788
1.68156076364744    1.32277838623733
-0.455916176089339  -0.632974493608950
-2.76038741468600   1.87628535124240
0.993963121269136   0.412382925821147
0.0813294944564905  0.00254834378164385
1.05785147371486    -0.713165079912121
0.542621317508334   0.263699015691544
0.0859471661820603  0.00284559667679037
0.0752254002940845  0.00264837949098051
-0.0821494531270125 -0.00258646752960803
-0.135286303232541  -0.0230503985166856
-1.04824146276167   0.379479302836832
-1.00411135626130   0.643815076295448
-1.06427192746705   -1.71485567599474
0.0306923117644997  -0.326399702175058
-0.269230352435044  1.15492815472443
-1.09071040094221   0.974587786723127
-0.0811137162377503 -0.00253932111442298
0.843300471645878   -0.443547135621555
2.62543922875650    -1.43287453338882
-0.0879222032042109 -0.00305697486042674
1.08943207983567    -0.751402936369758
-0.0807147111768526 -0.00252376120454932
0.0920673615786699  0.00345537914425264
-3.32572250550751   2.23334579177979
0.567347532732561   -0.849919751538726
-0.981291377531284  -1.65375737600341
0.717607651399507   -0.501535458162733

Now my C# Unity code looks like this:

using UnityEngine;
using System.Collections;
using System;
using System.IO;

public class WeightsMDF : MonoBehaviour
{

    private string text;
    void Start ()
    {
        FileInfo theSourceFile = new FileInfo 
        ("C:/Users/Ajdin/Downloads/UnitySpace/minorProject/Nerd/Nerds/Assets/Scenes/WeightsIH.txt");
        StreamReader reader = theSourceFile.OpenText();

        do
        {
            text = reader.ReadLine();
            string[] floats = text.Split(" "[0]);
            //Console.WriteLine(text);
            print (text); 
            //print(floats[0]);
        } while (text != null);   

    }
}

Now this code gives me the entire textfile in the console, but with a nullreferenceexeption at last: NullReferenceException: Object reference not set to an instance of an object WeightsMDF.Start () (at Assets/Scripts/Nerds/WeightsMDF.cs:19).

This exception refers to line 19:

string[] floats = text.Split(" "[0]);

Now if I comment this line, I get the same output except the last console output line says

Null

And If I change line 19 to:

string[] floats = text.Split(" ");//[0]);

I get the following compiling error:

Assets/Scripts/Nerds/WeightsMDF.cs(19,36): error CS1502: The best overloaded method match for `string.Split(params char[])' has some invalid arguments    
Assets/Scripts/Nerds/WeightsMDF.cs(19,36): error CS1503: Argument `#1' cannot convert `string' expression to type `char[]'

Does anyone know what I'm doing wrongly? Thanks in advance!

Still same NullReferenceException. Does it have something to do with the fact that the last element is somehow always Null? — WiseDev, Nov 28 '15 at 17:51
Are you sure that text does not equal null? May be reader.ReadLine returns null? — Valentin, Nov 28 '15 at 17:52

Valentin · Accepted Answer · 2015-11-28T18:40:53.107

0

Try to check text before use split. ReadLine returns null at the end of file, so you need check it before split.

text = reader.ReadLine();
if (text == null) 
     break;

string[] floats = text.Split(" "[0]);

Also, you can use Peek. It returns next symbol and doesn't use it and -1 if no symbols left.

        using (StreamReader sr = new StreamReader(path)) 
        {
            while (sr.Peek() >= 0) 
            {
                text = sr.ReadLine();
                var splits = text.Split (new string[] {" "}, StringSplitOptions.RemoveEmptyEntries);
            }
        }

To split string by whitespace you can use

string[] splits = text.Split(null);
string[] splits = text.Split(new char[0]);

edited Nov 28 '15 at 18:40

answered Nov 28 '15 at 17:55

Valentin

5,380
2
24
38

Thanks for trying to help. But as commented to Daniel Jo, It now gives me a compiler error at line: string[] floats = text.Split(' '); – WiseDev Nov 28 '15 at 18:00
Excuse me for asking, but isn't that last line js? Anyway, text.Split (new string[] {" "}); doesn't seem to work (and maybe not necessary anymore). I think I need an alternative argument in text.Split() to split between all the spaces, since it only fills the array with length 1. – WiseDev Nov 28 '15 at 18:22
@BlueRineS It's C#. There are 2 implementation of Split method. One use one character as parameter and split string by this character. Another one take array of strings and StringSplitOptions, so you can split string by several small strings. – Valentin Nov 28 '15 at 18:26
aah, thanks for clarification! And your line of code compiles, but it still outputs the entire lines, and doesn't split in between spaces, meaning that again it creats an array with length 1 instead of 2. I will also be browsing on other sources for the solution. – WiseDev Nov 28 '15 at 18:33
@BlueRineS Try this. http://stackoverflow.com/questions/6111298/best-way-to-specify-whitespace-in-a-string-split-operation – Valentin Nov 28 '15 at 18:39

Daniel Jo · Answer 2 · 2015-11-28T18:18:41.443

0

Instad of doing a do while loop, use a while loop with the condition: (!reader.EndOfStream).

For the split problem you need to send as parameter a char and not a string. with ' ' instead of " " like:

string[] floats = text.split(' ');

edited Nov 28 '15 at 18:18

answered Nov 28 '15 at 18:00

Daniel Jo

340
2
14

This seems to at least remove the NullReferenceException. Thanks for that. Now I will soon come back as to whether split works correctly. – WiseDev Nov 28 '15 at 18:06
All errors are gone. The problem still remains that the lines are not split correctly. The array contains only one element, while each line has two. This could be because each line contains multiple spaces, and so the entire line is filled in floats[0]? – WiseDev Nov 28 '15 at 18:14

Cannot convert data from textfile to array using .Split (C# Unity3D)

2 Answers2