df_variance_integer Function

public function df_variance_integer(df, col_index) result(var)

Calculate variance of integer column

Arguments

Type IntentOptional Attributes Name
type(data_frame), intent(in) :: df
integer, intent(in) :: col_index

Return Value real(kind=rk)


Source Code

    function df_variance_integer(df, col_index) result(var)
        type(data_frame), intent(in) :: df
        integer, intent(in) :: col_index
        real(rk) :: var

        integer(ik), dimension(:), allocatable :: col
        real(rk) :: avg
        type(column) :: data_col

        if (col_index < 1 .or. col_index > df % ncols()) error stop "column index out of range"

        data_col = df % get_data_col(col_index)
        if (data_col % get_type() /= INTEGER_NUM) error stop "column is not integer type"

        col = data_col % geti()
        avg = df_mean_integer(df, col_index)
        var = sum((real(col, rk) - avg)**2) / real(size(col) - 1, rk)
    end function df_variance_integer