Method and apparatus for a slider

A method for a piecewise linear mapping of data, on a graphical user interface having a data display region for displaying data according to a predetermined parameter, having a first parameter to data having a second parameter using a slider control, said method comprising the steps of:

• setting an upper limit with a first thumb of said slider control;
• mapping all values of said first parameter greater than said upper limit to an upper attribute;
• setting a lower limit independently of said upper limit with a second thumb of said slider control;
• mapping all values of said first parameter less than said lower limit to a lower attribute;
• and
• mapping all values of said first parameter between said upper limit and said lower limit to a transform function.

A method for a piecewise linear mapping of data, on a graphical user interface having a data display region for displaying data according to a predetermined parameter, having a first parameter to data having a second parameter using a slider control, said method comprising the steps of:

• setting an upper limit with a first thumb of said slider control;
• mapping all values of said first parameter greater than said upper limit to an upper attribute;
• setting a lower limit independently of said upper limit with a second thumb of said slider control;
• mapping all values of said first parameter less than said lower limit to a lower attribute;
• and
• mapping all values of said first parameter between said upper limit and said lower limit to a transform function;
• wherein said transform function is a color spectrum that varies in a defined manner as said first parameter takes on values between said upper limit and said lower limit.