[Numpy-discussion] hstack(arr_Int32, arr_float32) fails because of casting rules

Hi, I get TypeError: array cannot be safely cast to required type when calling hstack() ( which calls concatenate() ) on two arrays being a int32 and a float32 respectively. I understand now that a int32 cannot be safely converted into a float32 but why does concatenate not automatically up(?) cast to float64 ?? Is this really required to be done *explicitly* every time ? ** In general it makes float32 cubersome to use. ** ( Background: my large image data is float32 (float64 would require too much memory) and the hstack call happens inside scipy plt module when I try to get a 1d line profile and the "y_data" is hstack'ed with the x-axis values (int32)) ) Thanks, Sebastian Haase