Gantt Chart by Hand

I am constructing Gantt chart by hand. Using a monospaced font I can write

C-u 24 b -> xxxxxxxxxxxxxxxxxxxxxxxx

Which is great but I want to automate it in an org table. So I tried

(insert "x")         ;; doesn't work in org tables formulas
(insert-char 120 24) ;; also doesn't work

But that didn’t work due to the data type expected by the table. I order for this to work inside an org table, you should write a function that outputs a quoted string, like the following

(defun repeat(x n)
  ;; initialize the while loop
  (setq num 0) (setq b "")

  ;; concatenate to the empty string with each increment
  (while (< num n)
    (setq b (concat b x))
    (setq num (1+ num))
    )

  ;; output to be displayed
  (message b)
)

(repeat "x" 4) ;; C-x C-e gives "xxxx"

Now you can use it in an org table

| 24 | x | xxxxxxxxxxxxxxxxxxxxxxxx |
#+TBLFM: $3='(repeat $2 (string-to-number $1))

Extra

Understanding function scopes is important to avoid errors.

(defmath aziz1(x y)
   (math-floor (* 100 (/ x y)))
)

(calcFunc-aziz1 5 8) ;; => 62

(defun aziz2(x y)
  (math-floor (* 100 (/ x y))) ;; syntax not allowed inside defun
)

(aziz2 5 8) ;; => 0 

(defun aziz3(x y) 
  (calcFunc-aziz1 x y) 
)
(aziz3 5 8) ;; => 62 (calcFunc-aziz1 is callable)

Let’s modify the repeat function above to accept two inputs (nominator, denominator) based on the above.

(defun repeat2(x n1 n2)
  (defmath aziz1(x y)
    (math-floor (* 100 (/ x y)))
    )

  ;; initialize the while loop
  (setq num 0) (setq b "")

  (setq n (calcFunc-aziz1 n1 n2))

  ;; concatenate to the empty string with each increment
  (while (< num n)
    (setq b (concat b x))
    (setq num (1+ num))
    )

  ;; output to be displayed
  (message b)
)

(repeat "x" 1 30) ;; => xxx

We can then write the following table

| 1 | 30 | xxx    |
| 2 | 30 | xxxxxx |
#+TBLFM: $3='(repeat2 "x" $1 $2);N  

For more information on the ;N flag, see this.