/*
*
* An interval list used to map matrix elements into integers in the range 0 to
* 254 representing shades of gray on a PostScript printer. The list can be given
* using the -i option or can be set in the optional header that can preceed each
* matrix. The list should be a comma or space separated list that looks like,
*
*              num1,num2, ... ,numn
*
* where each num is a floating point number. The list must be given in increasing
* numerical order. The n numbers in the list partion the real line into 2n+1
* regions given by,
*
*              region1         element < num1
*              region2         element = num1
*              region3         element < num2
*              region4         element = num3
*                 .                 .
*                 .                 .
*                 .                 .
*              region2n        element = numn
*              region2n+1      element > numn
*
* Every number in a given region is mapped into an integer in the range 0 to 254
* and that number, when displayed on a PostScript printer using the image operator,
* prints as a square filled with a gray scale that reflects the integer that was
* chosen. 0 maps to black and 255 white (that's why 255 is normally omitted).
*
* The shades of gray chosen by the program are normally generated automatically,
* but can be reassigned using the -g option or by including a grayscale line in
* the optional header. The grayscale list is comma or space separated list of
* integers between 0 and 255 that's used to map individual regions into arbitray
* shade of gray, thus overriding the default choice made in the program. The list
* should look like,
*
*              color1,color2, ... ,color2n+1
*
* where color1 applies to region1 and color2n+1 applies to region2n+1. If less
* than 2n+1 numbers are given the default assignments will be used for the missing
* regions. Each color must be an integer in the range 0 to 255.
*
* The default interval list is given below. The default grayscale maps 254 (almost
* white) into the first region and 0 (black) into the last.
*
*/

#define DFLTILIST       "-1,0,1"

/*
*
* The active interval list is built from an interval string and stored in an array
* whose elements are of type Ilist.
*
*/

typedef struct  {
       double  val;                    /* only valid in kind is ENDPOINT */
       int     color;                  /* gray scale color */
       long    count;                  /* statistics for each region */
} Ilist;

/*
*
* Non-integer function declarations.
*
*/

char    *savestring();