Colour Range and Proportional Size

Use the Colour Range and Proportional Size opion to plot classified symbols using one channel to determine the symbol colours, and another one to determine the symbol sizes.

The Colour Range and Proportional Size option is available with the following extensions and menus:

• Map Tools > Symbols menu option (CLASYMB2 GX)

• Geochemistry extension: Geochem Map > Point Plots menu option (CHCLSYMB2 GX)

• Grav/Mag Interpretation extension: Euler 3D > Plot Solution Symbols menu option (CLASYMB2 GX)

Colour Range and Proportional Size dialog options

Colour channel	Select assay channel to plot from current database. The colours of the plotted symbols are selected according to different ranges of data in this channel. If the outlier limit is defined in the channel attributes, then values are clipped to that level.
Size channel	Select assay channel to plot from current database. The sizes of the plotted symbols are selected according to the data values in this channel. The symbol size in mm is given by the following relationship: Size (mm) = (Value – base) / Scale; If the outlier limit is defined in the channel attributes, then values are clipped to that level.
Zero base level (data units)	Zero base level (data units). This value is subtracted from the data value in the size channel, before the scaling factor is applied. Values less than or equal to the base level are not plotted.
Scale factor (data units/mm)	Symbol scale size units/mm.
Mask channel	Select a mask channel from the drop-down list. If the use of the mask channel is enabled and set to this channel, only those data values whose corresponding mask channel values are not dummy values will be plotted or exported.Channels must have their CLASS attribute set to MASK to appear as selections in the drop-down list. If the mask channel does not exist, it will be created with its CLASS attribute set to MASK. The default mask channel is set from the CHPREFERENCES GX (GeoChemMap/Preferences...).
Number of ranges	Number of ranges to plot, 1 to 12.
Symbol font name	Specify the symbol font name.
Symbol weight	Symbol weight, 7 weights available "Normal" (default).
Symbol edge colour	Symbol edge colour, black by default.
Symbol angle	The symbol angle (in degrees clockwise)
[Plot]	Click this button to create the symbol plot on your current map.
[Ranges]	Click this button to display a dialog for setting ranges, symbols and colours.
[Files]	Click this button to display the Load/Save to ITR File dialog for saving settings to an ITR file. Script Parameter: CHCLSYMB.ITR The name of the ITR file used for initial settings.

Specify Ranges dialog options

Maximum value for level 1	Specify maximum value for level 1 (lowest level) Additional levels must have values which increase or equal previous level. .
Maximum value for level #	Specify maximum value for level #.
...	...
Maximum value for level n-1	Specify maximum value for level n-1 (highest level).
[Symbols]	Click this button to display the Specify Symbols dialog for setting symbols for current ranges.
[Colours]	Click this button to display the Specify Fill Colours dialog for setting the colours of the symbols for the current ranges. Note that many of the symbols have no fill.

Application Notes

This GX uses the ITR’s (Image colour TRansform) register to store the additional symbol information. The ranges are specified in the same manner as for an ITR file. If there are n ranges, then n -1 maximum values are specified, because range n applies to all values from the maximum value specified for range n -1 to "infinity". A range value includes values up to and equal to the value.

For instance, the following example ITR has four ranges:

Index	Value	Data Range	Colour
0	10	<= 10	Red
1	20	10 < val <= 20	Green
2	30	20 < val <= 30	Blue
3	(not defined)	> 30	Yellow