PREFERENCES PANEL
Miscellaneous 1 tab

Advanced internet settings. If you use a proxy host, enter the name and port here. If you do not know the proxy settings, you will need to contact your ISP. Our tech support personnel cannot guess these settings or look them up for you. For example, users of Alphalink in Melbourne, Australia will notice on their Alphalink support pages that they would need to enter proxy.alphalink.com.au in "Proxy host" and 8080 in "Proxy port".

Color gradient fills - This section lets you define how gradient fills will look. It is designed mostly for experienced users and will require some basic mathematical knowledge. The colors are defined according to the plotted Value for the particular point on the map, which will always be in the range 0..1, where 0 is the lowest possible reading and 1 is the highest possible reading. This Value is fitted to a sine wave according to user defined parameters to determine the Red, Green, and Blue component of its color.

Photorealistic topography. This preference setting is only used in the full-blown version.

Cursor city locator - City size sensitivity factor. This controls which cities and towns will be accepted for use in the Map > Cursor city distance function. Reduce this number into the hundreds or thousands to allow comparisions with small towns. Increase the number into the tens of thousands to allow comparisions with only large cities. There is some variation in the sensitivity between different states and you may need to increase or decrease the factor for your region. To get an idea of what numbers you should use you may open the digatmos.cty file.

 

CONCEPTS OF COLOR GRADIENT FILLS

First the value (0 for minimum possible and 1 for maximum possible) is fitted to the sine wave to determine what the amplitude will be. Amplitude will always be in the range -1 to 1. Amplitude is determined by ph1 and ph2, which are in degrees. A greater difference between ph1 and ph2 will result in a more curved function, while a smaller difference will produce a flatter function. For basic users, the sine responses are as follows: sin(0)=0, sin(90)=90, sin(180)=0, sin(270)=-1 .

Amplitude = sin( [(ph2-ph1) * Value] + ph1 )

Finally the amplitude is modified according to the user-defined scale and offset values to determine ColorValue, which must always be in the range 0..1 (0 is dark, 1 is bright). This means if an Amplitude value is negative, it must be offset so that it falls into the range 0..1. An out of bounds ColorValue is always rounded up or down so that it equals 0 or 1.

ColorValue = (Amplitude * Scale) + Offset

Example: For a basic scale where cold temperatures are black and hot temperatures are bright red, set Red's Ph1=0, Ph2=90, Scale=1, and Offset=0. Set the Green and Blue Scale to 0 and Offset to 0, which will always provide a value of 0 for these components.

Illustration of basic concepts of Ph1, Ph2, Scale, and Offset.