// i.e., the Chinese character. The first of the two, <code>BitmapFile</code>
// is responsible for reading in data from a picture file
// stored in pbm ascii format. This data will be bilinearly interpolated and
- // provides in this way a function which describes an obstacle.
+ // thereby provides a function that describes the obstacle. (The code below
+ // shows how one can construct a function by interpolating between given
+ // data points. One could use the Functions::InterpolatedUniformGridData,
+ // introduced after this tutorial program was written, which does exactly
+ // what we want here, but it is instructive to see how to do it by hand.)
//
// The data which we read from the file will be stored in a double std::vector
// named obstacle_data. This vector composes the base to calculate a