Nearness field

The Nearness option allows you to configure a column to show a bar whose length and shading corresponds to the similarity of that crude in the database to a selected reference crude. The longer and deeper the colour, the more similar the reference crude is to the database crude.

Follow these steps to configure a nearness column for a view:

1. Choose Nearness from the Field drop-down list.

2. Select the Background calculation check box to perform the calculations for this column using background resources on the computer. This enables you to continue using Assay while the values in the column are being computed.

3. Select the reference crude from the Crude drop-down list.

4. Choose the Type of nearness calculation. You can choose among the following options:

   • Overall: This measure takes into account all the properties of the crudes when comparing them to the selected reference crude.

   • Yield: This measure takes account only of the yield distribution of the crudes when comparing them against the reference crude.

   • Monitor: The different Monitor options allow you to change the importance of common properties by selecting one of the different Monitor types. For more information on the different Monitor types see the table below.

     In addition to the predefined options, you will see listed any custom nearness definitions created in the Nearness Manager. In particular, there is a default read-only nearness definition called Sample. See Configure your nearness cases.

5. If desired, edit the Heading of the new column.

   The following table shows the different Monitor types and the weighting each type gives to different properties. For each different Monitor type a property can have a High (I) weighting, a Medium () weighting or a Low () weighting.

The illustration below shows a column in the database configured to show nearness to the reference crude ARBL91A Arab Light. To display those crudes in the database view nearest to Arab Light, you would click in the nearness column header to sort the database view by nearness to Arab Light.