Dynamic String Evaluation

An explanation of fields and properties

Evaluation 2D Strings Properties

To access this dialog:

Activate the Report ribbon and select Evaluate Dynamic | Strings
In the Command Line, run the command dynamic-evaluation-report.

You can also evaluate the contents of a wireframe volume. More...

Evaluation Background Information

Dynamic evaluation allows you to select one or more outlines and evaluate a block model (containing element grades) to find the tonnes, volume, and grade of elements over a specified depth. You can also report tonnes falling outside of the model if you wish, as a separate dilution reporting category.

The module evaluates in a dynamic sense, in that the outlines may be moved while the dialog is on-screen, causing updates to appear visually.

A block model must be loaded in order to progress with the dynamic evaluation.

Loading design outlines or creating them in your application does not populate the dialog automatically. To do this, the outlines must be selected. This can be performed after the dialog has been displayed.

The limit for projection distances is based on the elevation of each mining block string and not the intersection elevation of the block model in the 3D window.

String projection can be applied in a vertical direction or orthogonal to the currently active section.

A high-level view of a typical evaluation work flow would involve:

Medium-term planning is a process that is carried out on a regular basis. The output, for example, is a set of working outlines that indicate the grade and tonnage in the resource/reserve model over the period.
In addition to this, the planning department uses the outlines to produce the blast holes for each month’s drilling programme.
The mine planner, will typically define a series of outlines (as string data) to represent the mining area.
The mining zones are then evaluated.

Dynamic Evaluation Data Writeback

Both string and wireframe dynamic evaluation functions provide an option to update your input string or wireframe data with per-block evaluation results. This writeback functionality could be useful, for example, if you need to share mine planning solids with other teams (such as the operational team) or as a guide for design reviews.

To enable this behaviour, select the Write results back to... option in the evaluation settings dialog, e.g. for the Evaluation 2D Strings Properties dialog:

Following dynamic evaluation processing, the input string or wireframe data is appended with additional attributes, depending on which Grade Columns were selected above, e.g.:

The Dynamic Evaluation Dialog

This dialog is used to determine how previously designed/loaded evaluation string boundaries are to be used to create an evaluation zone (or zones) for the purpose of a model evaluation report.

For more information on defining evaluation zones with strings, see Dynamic Evaluation Reports.

The dialog allows you to specify the following evaluation criteria:

The resource model to use – this would already be populated with the single model that is loaded into the Design/VR window.
The legend and column to use for evaluation – this would be already populated with the applied legend, but may be changed to use a specific legend that is consistent throughout the use of the model.
The Density – this would be already populated but you may specify a default value instead of using a column from the block model.
The block identifier – this is assigned to the strings when the evaluation is performed.
Grade columns – the columns specified in this list are all the columns that occur in the block model. Select only those that are of interest for the evaluation.
Limit type – this displays the type of evaluation to be performed. Either an absolute elevation can be used with limits or the current elevation as specified in the Design/VR window with limits. The limits shown above are 0m upwards and 15m downwards, therefore evaluating a 15m bench from the specified elevation of the block model.

Many evaluations can be performed at the same time. Invoking the same command and specifying an Fe legend, an Fe name and requesting the Fe field in the output will drive both evaluations from the same selected strings.

The reasons for this are indicated below:

Different legends may be used with the same metal column (such as CuO) thereby allowing the user to evaluate the differences between legends.
Different metals such as CuO and Fe may be evaluated against different legends at the same time.
Different densities may be applied.
Different limits may be used to indicate how the grade varies with depth. This may be appropriate when benches are mined in 5m intervals over a 15m bench height. For this absolute elevation should be used.

This data may be modified once the evaluation is underway, so it is not all that important to provide accurate values in here.

When created, this dialog is used to define how the control string is to be projected, which model to evaluate, the evaluation legend and so on. These settings can have a significant impact on the evaluation results, so facilities have been incorporated to precisely control how an evaluation volume is created, and support for multiple strings is supported, even to the extent that each block of evaluated results can be identified in a saved results file, if required.

The Evaluation 2DStrings Properties dialog is used to define the block model, evaluation legend, density, block identifier, grade column and limit parameters before evaluating the selected mining block string(s).

A block model and mining blocks strings must be loaded before this dialog can be used. At least one string must be selected in the data window, drawn within the overall boundaries of a grade block model when viewed in the Z direction, for the evaluation process to report useful results.
This command is designed to work with strings that are coplanar and parallel to the XY plane i.e. plan view strings. All string are projected vertically when defining the upper and lower limits.

Dialog Field Details:

Model:

Name: accept the default or select another block model object from the drop-down; the selected model will be used for the evaluation. The current block model is displayed by default.

Include volume outside model in report?: if selected, the volume represented by your project evaluation string (either vertically or with respect to the currently active section) will report sub-volumes that fall outside of the model. If dilution is reported, you can choose a dilution reporting Category Name (see below).

Evaluation Legend:

Legend: optionally select a legend from the drop-down; this will determine the categories (CATEGORY field in the output evaluation results) for evaluation. This Legend field will, by default, display either the display legend (and associated Column), or the evaluation legend specified in Project Settings (Mine Design). Either the legend or the associated column can be changed if required (note: this will only affect your evaluation, and not the object display, or project settings).

Selecting the <none> Legend option will result in an evaluation with no individual categories i.e. the results table will contain a single evaluation record for all material within the selected volume, as shown below:

Selecting an evaluation legend from the Legend drop-down will result in an evaluation according to the defined legend items (categories). The results table will contain multiple entries, one for each category, as shown below:

Column: if a Legend has been defined, select the relevant data column from the drop-down.

The Evaluation Legend column will be disabled if a filter legend is used.

Density:

Default: define a global density value (default '1') to be used for evaluation. This value will be used where no density Column has been specified, or absent values are found within that column/field in the block model.

Column: select a block model field which contains density information. The standard density column/field is 'DENSITY', if present in the selected block model , it is automatically detected and selected.

Block Identifier:

This section only becomes important where multiple evaluation strings are to be used for the purposes of the same evaluation and when those results are not combined. When there are multiple blocks (perimeters/closed strings) to be evaluated, and you have chosen not to combine the results, the Block Identifier field can be used to identify the source of evaluation data in the resulting results file (saved using the Table View dialog).

If you do not intend to use multiple mining blocks during the evaluation, or you wish only to combine the results of all evaluation zones into a single set of records, this group of controls is not relevant and can be ignored.

See Dynamic Evaluation Reports for more information on the impact of combining evaluation block results.

Each mining block string used in the evaluation can be referenced in the report using its block identifier column/field. This can be any field, and a new field can be created if required. New block IDs will be written into the field for each string if no ID is currently present, or if the Overwrite existing IDs option has been selected.

The new Block IDs will start at the value specified in the “Default” option, and will increase by 0.01, by default, for each string. For example, the first evaluation boundary will give rise to evaluation records with a BLOCKID of 1.01; the second area will be reported with a BLOCKID of 1.02, and so on. The value by which the block ID is incremented can be specified in the Increment: box.

Default: accept the default start identifier value, or define a new one; this value is incremented by '0.01', by default, for each mining block. The default start ID is '1.01'.

Overwriting Existing IDs: select this option to overwrite any existing records in the results file; use this option when updating evaluation results as a result of either new block model information, or if the mining block has been modified.

Increment: for each string which is evaluated, the block identifier is increased by the amount specified in this box. The default is '0.01'.

Column: accept the default or select another column to store the Block ID values; this is stored both in the results file and the mining block strings.

Mined Value:

Block model cells that have a MINED value of '0' are treated as having been unmined. A value of '1' indicates that the block model cell has been completely mined out. Values between '0' and '1' indicate the portion (fraction) of the block that has been mined. If this option is selected then the proportion of the cell that is included in the results is the MINED value multiplied by the volume of the cell contained within the string.

Column: optionally select a mined out column. The standard field is MINED and if present in the block model, will automatically be detected and listed as the default.

If a MINED field is chosed, the model values in this field will be rewritten according to the option selected (see below).

If the MINED field is left blank, no changes will be made to the model object.

If a column is selected, the following options are available:

- Incremental: Incremental Mined mode assumes that where the block has been mined before, the current mined volume includes the previous mined volume (i.e. the previous volume has expanded). The largest of the previous and current mined percentages is stored in the MINED field, and the difference between the two is used for the evaluation.
- Additive: Additive Mined mode assumes that where the block has been mined before, the current mined volume does not include the previous mined volume (e.g. they are adjacent). The value stored in the MINED files is the sum of the previous and current mined volume, and the current volume is used in its entirety for the evaluation.

Report Category Name for Volume Outside of Model

If the Include volume outside model in report check box is selected, and the projected evaluation area falls outside of the model, the dilution volume can be reported in the output results table. This field is used to name the attribute that contains those dilution results.

Grade Columns:

Grade Columns List: select the required grade fields from the list i.e. select the check boxes; all fields detected in the selected block model, other than the default BLOCKID, DENSITY, TONNES,MINED and VOLUME (always listed in the resulting evaluation report) are listed here. You can choose any, all or none of the fields listed by enabling/disabling the check boxes next to a particular field's description.

Select: tick this box to use the column Name as a grade column for evaluation.

Name: name(s) of the detected, potential block model grade field(s).

Mode: select an option defining how the grade column is to be treated, select from [Tonnes Weighted] (default), [Volume Weighted], [Field Weighted], [Tonnes * Field Weighted], [Mass * Field Weighted], [Accumulated], [Dominant Value].

If [Field Weighted], [Tonnes * Field Weighted] or [Mass * Field Weighted] is selected, This weighting field must be present in the input model. If values for the weighting field (or the input grade field) are absent the resulting evaluated value for that record is absent.
If [Accumulated] is selected, The field values are accumulated and no weighting is calculated. E.g. a field containing values for time may be selected to use this option. This is the method used to calculate the values for VOLUME and TONNES.
If [Dominant Value] is selected, The most dominant value, by volume, is used as the result of the evaluation. This is the only permissible method used for alphanumeric fields.

Weight Column: if the [Field Weighted] Mode option has been selected, select a column from the dropdown .

Select None: deselect all listed grade fields.

Select All: select all listed grade fields.

Limits: use the parameters in this group to control how the selected string(s) are projected when the evaluation volume is generated:

Limit Type: select one of the two options:

Projection Distance: select this option to define the upper and lower vertical projection distance for the selected mining blocks using the defined Up and Down projection distances. This will define an evaluation volume according to a relative projection from the selected string(s), for example, 5 meters above and below the control string.

Projection, by default, will be applied vertically but this can be altered to an angle orthogonal to the current 3D section (Current Section). The Default projection distances and/or Column-based values will be applied in the chosen direction.
Absolute Elevation: select this option to define the upper and lower elevation limits for the selected mining blocks using the defined Maximum and Minimum elevations.

When the Absolute Elevation limit option is selected, the two group controls on the right change to Maximum and Minimum as shown below:

If using Absolute elevation settings for string projection, and both Minimum and Maximum values are identical, no evaluation will be performed.

Up (Maximum):

Default: define a default vertical upward projection distance or upper elevation value.

Column: select a data column (present in the mining block strings) that defines the Up values or Maximum elevations.

Down (Minimum):

Default: define a default vertical downward projection distance or lower elevation value.

Column: select a data column (present in the mining block strings) that defines the Down values or Minimum elevations.

Options:

Use full cell evaluation: If this toggle is on then evaluations against block models are done using entire cells. That is cells are considered to be wholly inside or outside the wireframe. If selected, the centroid of the sub-cell is checked to see whether it is inside the wireframe. If the centroid is inside, then 100% of the sub-cell volume is used for the evaluation; if the centroid is outside then 0% of the sub-cell volume is used.

Evaluations can be quicker if this option is selected, however, it is at the potential expense of accuracy.

Copy string attributes to results: allows you to copy all of the attributes from the evaluation string to the result file.

Write results back to strings: update your input string data with per-block evaluation results. An attribute will be added to the input string data for each Grade Column selected above.

OK: evaluate the currently selected mining block strings using the parameters defined in this dialog. This opens the Table View dialog, displaying the dynamic evaluation report.

Cancel: close the dialog without performing an evaluation.

Restore: restore previously applied evaluation settings from a previous session.

	Related Topics
	Dynamic Evaluation Reports Dynamic Evaluation Table View Dialog Wireframe Dynamic Evaluation