Thread

  1. A function to find errors in groups in a table

    Shaozhong SHI <shishaozhong@gmail.com> — 2022-06-09T13:37:27Z

    There is a table full of grouped values like the following
    
    nodeid     link_type      primary
    11           outflowlink       1
    11              inflowlink      1
    11              outflowlink     2
    
    Primary of 1 indicates a primary water course.  Primary of 2 indicates a
    secondary water course.
    
    Obviously, one of the out flow links is an error, as its primacy value is
    2.  It is wrong that water flows from a primary water course into a
    secondary water course.
    
    How can a function can be designed to find and report such errors?
    
    Regards,
    
    David
    
  2. A function to find errors in groups in a table

    Shaozhong SHI <shishaozhong@gmail.com> — 2022-06-09T13:37:54Z

    There is a table full of grouped values like the following
    
    nodeid     link_type      primary
    11           outflowlink       1
    11              inflowlink      1
    11              outflowlink     2
    
    Primary of 1 indicates a primary water course.  Primary of 2 indicates a
    secondary water course.
    
    Obviously, one of the out flow links is an error, as its primacy value is
    2.  It is wrong that water flows from a primary water course into a
    secondary water course.
    
    How can a function can be designed to find and report such errors?
    
    Regards,
    
    David
    
  3. Re: A function to find errors in groups in a table

    Steve Midgley <science@misuse.org> — 2022-06-09T19:16:12Z

    On Thu, Jun 9, 2022 at 6:37 AM Shaozhong SHI <shishaozhong@gmail.com> wrote:
    
    > There is a table full of grouped values like the following
    >
    > nodeid     link_type      primary
    > 11           outflowlink       1
    > 11              inflowlink      1
    > 11              outflowlink     2
    >
    > Primary of 1 indicates a primary water course.  Primary of 2 indicates a
    > secondary water course.
    >
    > Obviously, one of the out flow links is an error, as its primacy value is
    > 2.  It is wrong that water flows from a primary water course into a
    > secondary water course.
    >
    > How can a function can be designed to find and report such errors?
    >
    
    Is the problem that there exists this row:
    
    11              outflowlink     2
    
    But there is no corresponding row:
    
    11              inflowlink     2
    
    So that you need to find all "orphan" rows that don't have a corresponding
    member with the opposing data field inflowlink or outflowlink where the
    "primary" column is the join field between the two rows?
    
    Thanks for clarifying your problem,
    Steve
    
  4. Re: A function to find errors in groups in a table

    Shaozhong SHI <shishaozhong@gmail.com> — 2022-06-09T23:13:20Z

    The first two can be regarded right.  Certainly, the last one must be
    wrong.  How can a primary flow get into a secondary flow?
    
    That is odd.
    
    Regards,
    
    David
    
    On Thursday, 9 June 2022, Steve Midgley <science@misuse.org> wrote:
    
    >
    >
    > On Thu, Jun 9, 2022 at 6:37 AM Shaozhong SHI <shishaozhong@gmail.com>
    > wrote:
    >
    >> There is a table full of grouped values like the following
    >>
    >> nodeid     link_type      primary
    >> 11           outflowlink       1
    >> 11              inflowlink      1
    >> 11              outflowlink     2
    >>
    >> Primary of 1 indicates a primary water course.  Primary of 2 indicates a
    >> secondary water course.
    >>
    >> Obviously, one of the out flow links is an error, as its primacy value is
    >> 2.  It is wrong that water flows from a primary water course into a
    >> secondary water course.
    >>
    >> How can a function can be designed to find and report such errors?
    >>
    >
    > Is the problem that there exists this row:
    >
    > 11              outflowlink     2
    >
    > But there is no corresponding row:
    >
    > 11              inflowlink     2
    >
    > So that you need to find all "orphan" rows that don't have a corresponding
    > member with the opposing data field inflowlink or outflowlink where the
    > "primary" column is the join field between the two rows?
    >
    > Thanks for clarifying your problem,
    > Steve
    >
    
  5. Re: A function to find errors in groups in a table

    Steve Midgley <science@misuse.org> — 2022-06-09T23:25:27Z

    On Thu, Jun 9, 2022 at 4:13 PM Shaozhong SHI <shishaozhong@gmail.com> wrote:
    
    > The first two can be regarded right.  Certainly, the last one must be
    > wrong.  How can a primary flow get into a secondary flow?
    >
    > That is odd.
    >
    > Regards,
    >
    > David
    >
    > On Thursday, 9 June 2022, Steve Midgley <science@misuse.org> wrote:
    >
    >>
    >>
    >> On Thu, Jun 9, 2022 at 6:37 AM Shaozhong SHI <shishaozhong@gmail.com>
    >> wrote:
    >>
    >>> There is a table full of grouped values like the following
    >>>
    >>> nodeid     link_type      primary
    >>> 11           outflowlink       1
    >>> 11              inflowlink      1
    >>> 11              outflowlink     2
    >>>
    >>> Primary of 1 indicates a primary water course.  Primary of 2 indicates a
    >>> secondary water course.
    >>>
    >>> Obviously, one of the out flow links is an error, as its primacy value
    >>> is 2.  It is wrong that water flows from a primary water course into a
    >>> secondary water course.
    >>>
    >>> How can a function can be designed to find and report such errors?
    >>>
    >>
    >> Is the problem that there exists this row:
    >>
    >> 11              outflowlink     2
    >>
    >> But there is no corresponding row:
    >>
    >> 11              inflowlink     2
    >>
    >> So that you need to find all "orphan" rows that don't have a
    >> corresponding member with the opposing data field inflowlink or
    >> outflowlink where the "primary" column is the join field between the two
    >> rows?
    >>
    >
    You didn't answer my question, at least in a way I can understand, which
    makes it hard to give you useful input on a solution.. Also, please try to
    bottom post. This list asks posters to reply at the bottom of each email.
    
    Steve