[QST] How to update Table.column value in libcudf Java API

[hiroki-nishimoto-fixstars]

What is your question?

2 Questions.

1. How can I write bellow cudf(Python) code to libcudf(Java) code?
2. Are there any introduction or documents or example codes for libcudf(Java)?

---

Hi. I'm trying to rewrite cudf(Python) code to libcudf(Java) code.

In my understanding, they are implemented diffrenct concept. So, I do not believe that they are completely compatible, of course.

How can I write a process in libcudf(Java) that corresponds to the following process of updating a Series in a cudf.DataFrame?

libcudf(Java) prohibit to access Table.columns and don't have update column API. ex) setColumn(index, value)

import pandas as pd
df = pd.DataFrame({"a":[1,2,3], "b" : [4,5,6]})
df["a"] = [9,8,7]
print(df)


'''
output
  a b
0 9 4
1 8 5
2 7 6
'''

A simple implementation would yield the following code, which does not seem very smart.

Table df = ... // omission

ColumnVector update_a = ColumnVector.fromInts(9,8,7);
int numCols = df.getNumberOfColumns();
ColumnVector cols = new ColumnVector[numCols];
for( int i = 0 ; i < numCols; i++ ){
    if( i != 0 ){
        cols[i] = df.getColumn[i];
    }
    else {
        cols[i] = update_a;
    }
}
df = new Table(cols);

Also, I know there is libcudf(C++) documentation, but I could not find any Java documentation or example code. Is there somewhere I can find it?

Now I'm trying to implement with reading Test code and API implementation...