interpolate
Syntax
interpolate(X, [method=’linear’], [limit], [inplace=false], [limitDirection=’forward’], [limitArea])
Arguments
X is a numeric vector.
method is a string indicating how to fill the NULL values. It can take the following values and the default value is ‘linear’.
linear: for NULLs surrounded by valid values, fill the NULLs linearly. For NULLs outside valid values, fill the NULLs with the closest valid values.
pad: fill NULL values with existing values.
nearest: fill NULL values with the closest valid values.
krogh: fill NULL values with krogh polynomials.
limit is a positive integer indicating the maximum number of consecutive NULL values to fill.
inplace is a Boolean value indicating whether to update the input vector array. The default value is false, which means a new vector will be returned.
limitDirection is a string indicating the direction to fill NULL values. It can take the following values: ‘forward’, ‘backward’ and ‘both’. The default value is ‘forward’.
limitArea is a string indicating restrictions regarding filling NULL values. It can take the following values and the default value is empty string “”.
empty string: no restrictions.
inside: only fill NULLs surrounded by valid values.
outside: only fill NULLs outside valid values.
Details
Fill the NULL values in a vector.
Examples
$ a=[NULL,NULL,1,2,NULL,NULL,5,6,NULL,NULL];
$ interpolate(a);
[,,1,2,3,4,5,6,6,6]
$ interpolate(X=a, method="pad");
[,,1,2,2,2,5,6,6,6]
$ interpolate(X=a, limitDirection='both');
[1,1,1,2,3,4,5,6,6,6]
$ interpolate(X=a, limit=1, limitDirection='both');
[,1,1,2,3,4,5,6,6,]
$ interpolate(X=a, limitDirection='both', limitArea='outside');
[1,1,1,2,,,5,6,6,6]
$ a;
[,,1,2,,,5,6,,]
$ interpolate(X=a, limitDirection='backward', inplace=true);
[1,1,1,2,3,4,5,6,,]
$ a;
[1,1,1,2,3,4,5,6,,]