Result of combining multiple matrices turns into int32

I have several matrices, which I want to combine into one big matrix:

robotnumber =

       1
       2
       3
       4

orientation =

     -0.0002
    179.9671
      0.0020
    179.9953

detection =

             1         782
             1         782
             1         782
             1         782

detdistance =

      0.1533
      0.1483
      0.1569
      0.1647

spacer =

       0     0     0
       0     0     0
       0     0     0
       0     0     0

distance =

           0    2.1629    0.9540    3.8822
      2.1629         0    1.5346    2.1488
      0.9540    1.5346         0    3.5705
      3.8822    2.1488    3.5705         0

But, if I try the following code:

Robotinfo = [robotnumber,orientation,detection,detdistance,speed,spacer,distance];

All the data goes, apparently, through an int32 function, resulting in:

Robotinfo =

The workspace also says: Robotinfo 4x14 int32, instead of Robotinfo 4x14 single.

Does anyone know what causes this problem?

Thanks!

Answer 1

[Guillaume]

Most likely one of your variable is int32. As a result, all the other variables are implicitly converted to int32. Convert it to double before concatenating it.

concat = [dblvar, dblvar, double(int32var)];

rant: Most languages have made the sensible decision that implicit conversions are widening. That is, an implicit conversion will only happen if there is no loss of data (e.g. int8 -> int32, float->double or int->double). Matlab, on the other hand has narrowing conversions. An int32 will get demoted to an int8 with all the loss of data that ensues. Same with double->float or as in your case double->int. Completely absurd!

[Stijn]

Thanks!