Transform channel
This function is a special graphics editing function which permits you to move all or part of a string thus bending the string around corners. The ability to bend the string around corners is especially useful for editing channel strings, as they typically follow the outline of the mine workings. Since the surveys are generally only approximate, it becomes necessary to "bend" the strings to follow the shape of the workings.
To run this function: Choose Design > Grade control > Modify channel survey, or...
This function works by performing a rotation and possibly translation to some or all of the points in the channel strings. To enable this transformation to be performed, you must select two existing points on the channel string and then, if the start of the channel has been selected, digitise two new positions to define the new location of the string. If the start of the channel was not selected you digitize only one new point so that part of the string will be rotated about the first selected point.
Note: This function can
only work in Plan view, Section view or Long section view. It will issue
a warning message if you attempt to use it in any other view.
Select the first point
Select a point on the channel string which is to be edited. If you wish to translate the entire string to a new location you MUST select the point at the start of the string. If you only wish to rotate a portion of the string, then select the point about which the rotation is to be performed. Select the first point to display the prompt:
Select the second point
Select another point on the string to be edited. This second point must be further along the string than the first selected point.
If the first selected point was at the start of the string then the next prompt to be displayed will be:
Digitise the first point new position
Digitise the location to which the first selected point is to be moved. If the first selected point was not at the start of the string then only the following prompt will be displayed:
Digitise the second point new position
Digitise a new position for the second point. Note this is not really the location to which the second point will be moved, unless you happen to be lucky enough to digitise it such that it is exactly the same distance from the new position of the first point as the original second point is away from the original first point.
The result of this function varies depending upon whether you selected the first point of the string or not.
If you happened to select the first point of the string then you have in effect defined a transformation which involves translation and rotation components. This results in all points in the string being translated by the difference between the old and new positions of the first point, followed by a rotation about the first point, with the magnitude of the rotation being determined by the difference in bearings of the lines between the first pair of points and the second pair of points.
If the first selected point was not at the start of the string, then the transformation only involves a rotation about the first selected point. The magnitude of the rotation is determined by the difference in bearing of the lines between the first pair of selected points and the first selected point and the digitised location for the second point.
The transformations do not scale the data at all and so the lengths of the samples in the string are always maintained.
After transforming the string, the string is erased and redrawn in its new position and the cycle of selecting and digitising points will continue until you press Escape to exit the function.