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TAN

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github-actions[bot] edited this page Jun 16, 2022 · 5 revisions

The TAN function returns the ratio of SINe to COSine or tangent value of an angle measured in radians.

Syntax

tangent! = TAN(radian_angle!)

Parameters

  • The radian_angle must be measured in radians.

Description

  • To convert from degrees to radians, multiply degrees * π/180.
  • TANGENT is the gradient or slope of the circle or arc at SIN(θ) / COS(θ). Do not use division when the COS = 0 to avoid errors.
Example: Spiraling text using the SIN and TAN functions. 
CALL analyse
CLS
CALL redraw

SUB analyse
CLS
SCREEN 12
COLOR 2: LOCATE 1, 1: PRINT text$
DIM px AS INTEGER, py AS INTEGER, cnt AS INTEGER, ltrcnt AS INTEGER
px = 1: py = 1
DO
  word(px, py) = POINT(px, py)
  PSET (px, py), 1
  px = px + 1
  IF...THEN px = LEN(text$) * 8 THEN
    px = 1
    py = py + 1
  END IF
LOOP UNTIL py = 16
END SUB

SUB redraw
CLS
DIM row AS INTEGER, cnt AS INTEGER, cstart AS SINGLE, cend AS SINGLE
DIM xrot AS INTEGER, yrot AS INTEGER, SCALE AS INTEGER, pan AS INTEGER
cstart = 0: cend = 6.2
xrot = 6: yrot = 6: SCALE = 3: pan = 30
OUT &H3C8, 1: OUT &H3C9, 10: OUT &H3C9, 10: OUT &H3C9, 60
DO
  row = 2
  DO
    DO
      FOR...NEXT i = cend TO cstart STEP -.03
        x = (SCALE * 60 - (row * xrot / 4)) * TAN(COS(i))
        y = SIN(SCALE * 60 - (row * yrot)) * TAN(SIN(i)) * pan
        cnt = cnt + 1
        IF...THEN word(cnt, row) > 0 THEN 
          CIRCLE (x + 320, y + 220), SCALE + 1, 1              'circled letters
          'LINE (x + 320, y + 220)-STEP(12, 12), 1, BF  'boxed letters
        END IF
        IF...THEN cnt = LEN(text$) * 8 THEN cnt = 0: EXIT DO
      NEXT
    LOOP
    row = row + 1
  LOOP UNTIL row = 16
  cend = cend + .1
  cstart = cstart + .1
  now! = TIMER
  DO
    newnow! = TIMER
  LOOP UNTIL newnow! - now! >= .15
  LINE (1, 100)-(639, 280), 0, BF
LOOP UNTIL INKEY$ = CHR$(27)
END SUB '' ''
Code by Unseen Machine

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