Gri: `heal' command

Gri Commands 1: Introduction 2: Simple example 3: Fancy example 4: Running Gri 5: Programming Gri 6: General Issues 7: X-Y Plots 8: Contour Plots 9: Image Plots 10: Examples 11: Handling Data 12: Gri Commands 13: Gri Extras 14: Evolution of Gri 15: Installing Gri 16: Gri Bugs 17: System Tools 18: Acknowledgments 19: License 20: Newsgroup 21: Concept Index | ## 12.15: The ``heal`' Command
    heal columns|{columns along x|y}
- The ``heal`' command heals over gaps in either columnar or gridded data. This is done by linear interpolation across the missing-value gaps. ``heal columns`' Fill in missing values in x, y, z, ... columns, by linear interpolation to neighboring valid data. All gaps in the data will get replaced by a linear function of index which matches the data at the indices just before and just after the gap. For example, if the y data were like
      111
      3
      -9
      -9
      -9
      7
      333
  where ``-9`' is the missing-value code, then they would get replace by
      111
      3
      4
      5
      6
      7
      333
Notes: (1) This is done independently for all existing columns. (2) Gaps at the start and end of the columns are not filled in. ``heal grid along x`' Scan in the x direction, filling in missing values by linear interpolation. Since this uses the the x-grid, you must first have done ``read grid x`' or ``set x grid`'. ``heal grid along y`' Scan in the y direction, filling in missing values by linear interpolation. Since this uses the the y-grid, you must first have done ``read grid y`' or ``set y grid`'.