message: Fixing more documentation 2
diff: @@ -35,27 +35,28 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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  <PRE><B>
  enum class fill_policy : unsigned char {
  + // Fill all missing values with the given substitute
  value = 1,
  +
  + // Fill the missing values with the previous value
  fill_forward = 2,
  +
  + // Fill the missing values with the next value
  fill_backward = 3,
  - linear_interpolate = 4, // Using the index as X coordinate
  - linear_extrapolate = 5, // Using the index as X coordinate
  - mid_point = 6, // Mid-point of x and y
  +
  + // X - X<sub>1</sub>
  + // Y = Y<sub>1</sub> + --------- * (Y<sub>2</sub> - Y<sub>1</sub>)
  + // X<sub>2</sub> - X<sub>1</sub>
  + // Use the index column as X coordinate and the given column as Y coordinate
  + linear_interpolate = 4,
  + linear_extrapolate = 5,
  +
  + // Fill missing values with mid-point of surrounding values
  + mid_point = 6,
  };</B></PRE></font>
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  <td>
  This policy determines how to fill missing values in the DataFrame<BR>
  - value: Fill all the missing values, in a given column, with the given value.<BR>
  - <B>fill_forward</B>: Fill the missing values, in a given column, with the last valid value before the missing value<BR>
  - <B>fill_backward</B>: Fill the missing values, in a given column, with the first valid value after the missing value<BR>
  - <B>linear_interpolate</B>:<BR>
  - <B>linear_extrapolate</B>:<BR>
  - Use the index column as X coordinate and the given column as Y coordinate And do interpolation/extrapolation as follows:<BR>
  - <PRE>
  - X - X1
  - Y = Y1 + ----------- * (Y2 - Y1)
  - X2 - X1
  - </PRE>
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