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'.