If you entered replicate values (side by side), you can later choose if you want the heat map to be based on the mean, median or geometric mean. You can even choose to make a heat make of variation, and base the heat map on the SD, %CV or SEM of replicate values.
Color map and range
There are four choices of color maps:
•Single gradient. Choose the range of values to convert to colors and the range of colors.
•Grayscale. You can choose whether black or white is for the lower value, and what the range of values is.
•Rainbow. You choose the range of data values. Prism chooses the range of colors by fixing the saturation and brightness to 100% and varying the hue from 0˚ to 300˚. Using the Rainbow color map, the largest values are shown in red. If you select the Reverse Rainbow color map, the smallest values are encoded red.
•Double gradient. You choose the baseline value (almost always 0.0) and color (usually white or black). Then separately enter the maximum value (almost always positive) and color, and also enter the minimum value (almost always negative) and color.
•Categorical. Enter a value or range of values, and what color you want it to show as. Repeat as needed. Ranges cannot overlap. You can't have one range "1-2" and another "2-3" because that would leave it ambiguous how to encode 2.0000. Instead do something like this -- one rage for "1.0-1.99" and another for "2.0-2.99".
Off the map
Choose a color to use if the value is too large or too small to be part of the map you defined, or if the value is blank or excluded. Of course, these choices are irrelevant if no values are off scale, blank or excluded. To make blank and excluded values more apparent, check an option to place a black X through those cells. Since the X is always black, use a light color to encode these cells.