Info Catalog eintr: Y Axis Element eintr: print-Y-axis eintr: print-Y-axis Penultimate

eintr: Y-axis-column

 
 C.2.3 Create a Y Axis Column
 ----------------------------
 
 The preceding functions provide all the tools needed to construct a
 function that generates a list of numbered and blank strings to insert
 as the label for the vertical axis:
 
      (defun Y-axis-column (height width-of-label)
        "Construct list of Y axis labels and blank strings.
      For HEIGHT of line above base and WIDTH-OF-LABEL."
        (let (Y-axis)
          (while (> height 1)
            (if (zerop (% height Y-axis-label-spacing))
                ;; Insert label.
                (setq Y-axis
                      (cons
                       (Y-axis-element height width-of-label)
                       Y-axis))
              ;; Else, insert blanks.
              (setq Y-axis
                    (cons
                     (make-string width-of-label ? )
                     Y-axis)))
            (setq height (1- height)))
          ;; Insert base line.
          (setq Y-axis
                (cons (Y-axis-element 1 width-of-label) Y-axis))
          (nreverse Y-axis)))
 
    In this function, we start with the value of ‘height’ and
 repetitively subtract one from its value.  After each subtraction, we
 test to see whether the value is an integral multiple of the
 ‘Y-axis-label-spacing’.  If it is, we construct a numbered label using
 the ‘Y-axis-element’ function; if not, we construct a blank label using
 the ‘make-string’ function.  The base line consists of the number one
 followed by a tic mark.
 

Info Catalog eintr: Y Axis Element eintr: print-Y-axis eintr: print-Y-axis Penultimate