Flowcharting

Flowchart elements are defined in the flow module.

from schemdraw import flow

It’s a Trap!

Recreation of XKCD 1195.

with schemdraw.Drawing() as d:
    flow.Start().label('START')
    flow.Arrow().down(d.unit/3)
    h = flow.Decision(w=5.5, h=4, S='YES').label('Hey, wait,\nthis flowchart\nis a trap!')
    flow.Line().down(d.unit/4)
    flow.Wire('c', k=3.5, arrow='->').to(h.E)

Flowchart for flowcharts

Recreation of XKCD 518.

with schemdraw.Drawing() as d:
    d.config(fontsize=11)
    b = flow.Start().label('START')
    flow.Arrow().down(d.unit/2)
    d1 = flow.Decision(w=5, h=3.9, E='YES', S='NO').label('DO YOU\nUNDERSTAND\nFLOW CHARTS?')
    flow.Arrow().length(d.unit/2)
    d2 = flow.Decision(w=5, h=3.9, E='YES', S='NO').label('OKAY,\nYOU SEE THE\nLINE LABELED\n"YES"?')
    flow.Arrow().length(d.unit/2)
    d3 = flow.Decision(w=5.2, h=3.9, E='YES', S='NO').label('BUT YOU\nSEE THE ONES\nLABELED "NO".')

    flow.Arrow().right(d.unit/2).at(d3.E)
    flow.Box(w=2, h=1.25).anchor('W').label('WAIT,\nWHAT?')
    flow.Arrow().down(d.unit/2).at(d3.S)
    listen = flow.Box(w=2, h=1).label('LISTEN.')
    flow.Arrow().right(d.unit/2).at(listen.E)
    hate = flow.Box(w=2, h=1.25).anchor('W').label('I HATE\nYOU.')

    flow.Arrow().right(d.unit*3.5).at(d1.E)
    good = flow.Box(w=2, h=1).anchor('W').label('GOOD')
    flow.Arrow().right(d.unit*1.5).at(d2.E)
    d4 = flow.Decision(w=5.3, h=4.0, E='YES', S='NO').anchor('W').label('...AND YOU CAN\nSEE THE ONES\nLABELED "NO"?')

    flow.Wire('-|', arrow='->').at(d4.E).to(good.S)
    flow.Arrow().down(d.unit/2).at(d4.S)
    d5 = flow.Decision(w=5, h=3.6, E='YES', S='NO').label('BUT YOU\nJUST FOLLOWED\nTHEM TWICE!')
    flow.Arrow().right().at(d5.E)
    question = flow.Box(w=3.5, h=1.75).anchor('W').label("(THAT WASN'T\nA QUESTION.)")
    flow.Wire('n', k=-1, arrow='->').at(d5.S).to(question.S)

    flow.Line().at(good.E).tox(question.S)
    flow.Arrow().down()
    drink = flow.Box(w=2.5, h=1.5).label("LET'S GO\nDRINK.")
    flow.Arrow().right().at(drink.E).label('6 DRINKS')
    flow.Box(w=3.7, h=2).anchor('W').label('HEY, I SHOULD\nTRY INSTALLING\nFREEBSD!')
    flow.Arrow().up(d.unit*.75).at(question.N)
    screw = flow.Box(w=2.5, h=1).anchor('S').label('SCREW IT.')
    flow.Arrow().at(screw.N).toy(drink.S)

State Machine Acceptor

Source

with schemdraw.Drawing() as d:
    elm.Arrow().length(1)
    s1 = flow.StateEnd().anchor('W').label('$S_1$')
    elm.Arc2(arrow='<-').at(s1.NE).label('0')
    s2 = flow.State().anchor('NW').label('$S_2$')
    elm.Arc2(arrow='<-').at(s2.SW).to(s1.SE).label('0')
    elm.ArcLoop(arrow='<-').at(s2.NE).to(s2.E).label('1')
    elm.ArcLoop(arrow='<-').at(s1.NW).to(s1.N).label('1')

Door Controller

Diagram Source

with schemdraw.Drawing() as d:
    d.config(fontsize=12)
    delta = 4
    c4 = flow.Circle(r=1).label('4\nopening')
    c1 = flow.Circle(r=1).at((delta, delta)).label('1\nopened')
    c2 = flow.Circle(r=1).at((2*delta, 0)).label('2\nclosing')
    c3 = flow.Circle(r=1).at((delta, -delta)).label('3\nclosed')
    elm.Arc2(arrow='->', k=.3).at(c4.NNE).to(c1.WSW).label('sensor\nopened')
    elm.Arc2(arrow='->', k=.3).at(c1.ESE).to(c2.NNW).label('close')
    elm.Arc2(arrow='->', k=.3).at(c2.SSW).to(c3.ENE).label('sensor\nclosed')
    elm.Arc2(arrow='->', k=.3).at(c3.WNW).to(c4.SSE).label('open')
    elm.Arc2(arrow='<-', k=.3).at(c4.ENE).to(c2.WNW).label('open')
    elm.Arc2(arrow='<-', k=.3).at(c2.WSW).to(c4.ESE).label('close')

Another State Machine

with schemdraw.Drawing():
    a = flow.Circle().label('a').fill('lightblue')
    b = flow.Circle().at((4, 0)).label('b').fill('lightblue')
    c = flow.Circle().at((8, 0)).label('c').fill('lightblue')
    f = flow.Circle().at((0, -4)).label('f').fill('lightblue')
    e = flow.Circle().at((4, -6)).label('e').fill('lightblue')
    d = flow.Circle().at((8, -4)).label('d').fill('lightblue')
    elm.ArcLoop(arrow='->').at(a.NW).to(a.NNE).label('00/0', fontsize=10)
    elm.ArcLoop(arrow='->').at(b.NNW).to(b.NE).label('01/0', fontsize=10)
    elm.ArcLoop(arrow='->').at(c.NNW).to(c.NE).label('11/0', fontsize=10)
    elm.ArcLoop(arrow='->').at(d.E).to(d.SE).label('10/0', fontsize=10)
    elm.ArcLoop(arrow='->').at(e.SSE).to(e.SW).label('11/1', fontsize=10)
    elm.ArcLoop(arrow='->').at(f.S).to(f.SW).label('01/1', fontsize=10)
    elm.Arc2(k=.1, arrow='<-').at(a.ENE).to(b.WNW).label('01/0', fontsize=10)
    elm.Arc2(k=.1, arrow='<-').at(b.W).to(a.E).label('00/0', fontsize=10)
    elm.Arc2(k=.1, arrow='<-').at(b.ENE).to(c.WNW).label('11/0', fontsize=10)
    elm.Arc2(k=.1, arrow='<-').at(c.W).to(b.E).label('01/0', fontsize=10)
    elm.Arc2(k=.1, arrow='<-').at(a.ESE).to(d.NW).label('00/0', fontsize=10)
    elm.Arc2(k=.1, arrow='<-').at(d.WNW).to(a.SE).label('10/0', fontsize=10)
    elm.Arc2(k=.1, arrow='<-').at(f.ENE).to(e.NW).label('01/1', fontsize=10)
    elm.Arc2(k=.1, arrow='<-').at(e.WNW).to(f.ESE).label('11/1', fontsize=10)
    elm.Arc2(k=.1, arrow='->').at(e.NE).to(d.WSW).label('11/1', fontsize=10)
    elm.Arc2(k=.1, arrow='->').at(d.SSW).to(e.ENE).label('10/0', fontsize=10)
    elm.Arc2(k=.1, arrow='<-').at(f.NNW).to(a.SSW).label('00/0', fontsize=10)
    elm.Arc2(k=.1, arrow='<-').at(c.SSE).to(d.NNE).label('10/0', fontsize=10)

Logical Flow Diagram

with schemdraw.Drawing(unit=1) as dwg:
    a = flow.Circle(r=.5).label('a')
    x = flow.Decision(w=1.5, h=1.5).label('$X$').at(a.S).anchor('N')
    elm.RightLines(arrow='->').at(x.E).label('$\overline{X}$')
    y1 = flow.Decision(w=1.5, h=1.5).label('$Y$')
    dwg.move_from(y1.N, dx=-5)
    y2 = flow.Decision(w=1.5, h=1.5).label('$Y$')
    elm.RightLines(arrow='->').at(x.W).to(y2.N).label('$X$')
    elm.Arrow().at(y2.S).label('$Y$')
    b = flow.Circle(r=.5).label('b')
    dwg.move_from(b.N, dx=2)
    c = flow.Circle(r=.5).label('c')
    elm.RightLines(arrow='->').at(y2.E).to(c.N).label('$\overline{Y}$')
    elm.Arrow().at(y1.S).label('$Y$')
    d = flow.Circle(r=.5).label('d')
    dwg.move_from(d.N, dx=2)
    e = flow.Circle(r=.5).label('e')
    elm.RightLines(arrow='->').at(y1.E).to(e.N).label('$\overline{Y}$')