Module column 

Kernels on a whole NdColumn: one kernel call for all rows.

The values child of a column holds the values of all rows, one after another. An elementwise kernel can run on that child once and keep the offsets and dimensions. This replaces one call per row with one call per column.

Functions

column_binary

Apply an elementwise binary kernel to two columns, for example compute::add.

column_cast

Cast the values of all rows. Keeps the attributes.

column_decode_cf

Decode CF packing and fill values of every row, see decode_cf.

column_unary

Apply an elementwise unary kernel to all rows in one call, for example column_unary(&c, compute::sqrt, false).

row_reduce

Reduce every row over all its axes: one value per row, like a SQL aggregate per row. A null row gives null.

row_reduce_axes

Reduce every row over the named axes. Rows without an axis keep it out of the reduction. Returns a new column.

valid_rows

Indices of non-null rows. Helper for callers that filter columns.