ffill!

ffill!(obj, [limit])

If obj is a vector, forward fill the null values in obj with the previous non-null value.

If obj is a matrix or a table, forward fill the null values in each column of obj with the previous non-null value.

obj is a vector/matrix/table.

limit is a positive integer that specifies the number of null values to forward fill for each block of null values.

It returns an object after filling null values, with the same type and form as obj.

Example 1

x=1 2 3 NULL NULL NULL 4 5 6
x.ffill!(); 
x; 
// The value of x is changed. 
// output: [1,2,3,3,3,3,4,5,6]

Example 2: Specify parameter limit = 1. The first null value is filled.

x=1 2 3 NULL NULL NULL 4 5 6
x.ffill!(1);
// output: [1,2,3,3,,,4,5,6]

Example 3: Specify obj as a table.

date=[2012.06.12,2012.06.12,2012.06.13,2012.06.14,2012.06.15]
sym=["IBM","MSFT","IBM","MSFT","MSFT"]
price=[40.56,26.56,,,50.76]
qty=[2200,4500,,5600,]
timestamp=[09:34:07,09:35:26,09:36:42,09:36:51,09:36:59]
t=table(date,timestamp,sym,price,qty);
ffill!(t); 
t;