Classify strings by numbers
It is often useful to be able to classify the strings in a file based on the value contained in a certain field. This value may be an elevation, or a numeric attribute, for example a contaminating or assay grade value, or any other numeric value you choose to put there. Strings can be classified based on the Y, X, Z or description fields D1 to D100.
In particular, this is useful to get data classified into separate strings which may then be plotted with different attributes.
To run this function: Choose File tools > Classify strings by numbers, or...
Fields on the Classify strings by a numeric field form.
Define the input files
Location, ID range, Use descriptions
Identify a range of files to be classified in the usual way. If descriptions are to be retained in the output string file answer (Y)es or (N)o if descriptions are not to be retained.
Define the output files
Identify the Location of the output files. A corresponding output file will be produced for each input file.
Number of classification passes
This is the number of distinctly different classification passes that are required to classify the input data.
Most applications will only require one classification pass. This is typical when the entire input file is classified into a number of classes or grade ranges in the output file. Therefore the most common entry here is 1.
Use of more than 1 classification pass is common when, for example, the input data is already classified into more than 1 group. An example of this would be Proven, Possible and Probable classes for an ore reserve. In this instance, Proven may be represented by string 1, Possible may be represented by string 2 and Probable by string 3.
By using 3 classification passes, each of these different classes of ore reserves can be sub-classified into different strings based on grade value. It is therefore possible to achieve something like:
| Ore type | Input string | Output String | Grade Range |
|---|---|---|---|
| Proven | 1 | 1 | 0.0 > grade <= 1.5 |
| 2 | 1.5 > grade <= 3.0 | ||
| 3 | 3.0 > grade <= 999.0 | ||
| Possible | 2 | 11 | 0.0 > grade <= 1.5 |
| 12 | 1.5 > grade <= 3.0 | ||
| 13 | 3.0 > grade <= 999.0 | ||
| Probable | 3 | 21 | 0.0 > grade <= 1.5 |
| 22 | 1.5 > grade <= 3.0 | ||
| 23 | 3.0 > grade <= 999.0 |
When using multiple classification passes, whether to classify by segment or point remain constant for all classification passes.
CLASSIFICATION PASS 1
Parameters for the first classification pass are entered on the first form. Typically only one classification pass is needed and, in this case, all parameters required can be entered using this first form. If more than one classification pass is required subsequent forms are displayed to input the parameters for each classification pass.
Input string range
Enter the range of input strings to examine for this classification pass. A blank field indicates all input strings will be processed.
Classifying field
You may classify the segments or points based on any field in each record. Valid entries here are Y, X, Z, D1, D2, etc. corresponding to the Y, X, Z, point/segment first description value, point/segment second description value, etc. Missing, non-numeric or blank description fields are assigned to the first output string.
Classify by
Valid entries are segment or point.
Strings may be classified by individual points, regardless of their string number, or by their segments, such as for strings composed of digitized zones.
Input method
Valid entries are table or range.
The output strings can be defined using a table (default) or a range of output strings and a corresponding range of grade values.
Table method
Output string ID
The ID of each output string.
MIN field value, MAX field value
The upper and lower bound of the input point/segment classification field that the output string will correspond to. Note that an unspecified minimum value indicates no lower bound. Similarly an unspecified maximum value indicates no upper bound.
Range method
Output string range, Output grade range
Two ranges are used to specify the output strings. The output string range specifies the IDs of the output strings and the grade range specifies a set of grade intervals that each correspond to a string in the output string range.
These value ranges follow the convention of greater than or equal to the lower value, and less than the upper value. For example - a range from 0.000 to 0.055 covers all values from 0.000 to 0.054999..., but does not include the value 0.055. Generally the next range would start from 0.055 to another higher number, and the value 0.055 would then be classed as belonging to this range.
CLASSIFICATION PASS x
`x' denotes an integer identifying the classification pass.
Parameters for the subsequent classification passes are entered using a set of input forms. Each classification pass uses one form to enter the parameters required. By clicking the Previous and NEXT buttons you can enter details for the different classification passes. For the last classification pass the NEXT button is replaced by an APPLY button to commence classification. Similarly, the PREVIOUS button on the form for the first classification pass is replaced by a CANCEL button to abort the Classify Strings function.
Input string range
Enter the range of input strings to examine for this classification pass. A blank field indicates all input strings will be processed.
Classifying field
The value entered on the first form for this field is displayed for reference. This is done to ensure consistency in the classification of the data.
Note that Missing, non-numeric or blank description fields are assigned to the first output string.
Classify by
The value entered on the first form for this field is displayed for reference. This value cannot be changed on this form. This is done to ensure consistency in the classification of the data.
Input method
Valid entries are table or range.
The output strings can be defined using a table (default) or a range of output strings and a corresponding range of grade values.
Table method
Output string ID
The ID of each output string.
MIN field value, MAX field value
The upper and lower bound of the input point/segment classification field that the output string will correspond to. Note that an unspecified minimum value indicates no lower bound. Similarly an unspecified maximum value indicates no upper bound.
Range method
Output string range, Output grade range
Two ranges are used to specify the output strings. The output string range specifies the IDs of the output strings and the grade range specifies a set of grade intervals that each correspond to a string in the output string range.
These value ranges follow the convention of greater than or equal to the lower value, and less than the upper value. For example - a range from 0.000 to 0.055 covers all values from 0.000 to 0.054999..., but does not include the value 0.055. Generally the next range would start from 0.055 to another higher number, and the value 0.055 would then be classed as belonging to this range.
Result
The result will be a range of output files in which each string contains only points and or segments within one of the nominated classification ranges.
Note:Any data in the input files with a selection field value not in any of the ranges specified is not copied to the new, classified files. Warning messages are displayed for each value that is not classified according to the entered specifications.
Points, or segments if classifying by segment, can only be classified into a single string number in the output file. It is not possible to classify a point or segment into 2 or more strings even if multiple classification passes define overlapping ranges. The first value range encountered that contains a point or segment determines the string number of the result.