2.3 Roc left

R figure

Code

h <- 50 
w <- 50 

grid.step <- 10

TP1 <- 30
FP1 <- 10
TP2 <- 20
FP2 <- 20
TP3 <- 40
FP3 <- 20

plot( c(0,w), c(0,h),  
     xaxs = "i",yaxs = "i",
     xaxt = 'n', yaxt = 'n',
     type = "n",
     xlab = "Negatives", ylab = "Positives")

axis(2,c(0,TP2,TP1,TP3,h),labels=c('0','TP2','TP1','TP3','Pos'))
axis(1,c(0,FP1,FP2,w),labels=c('0','FP1','FP2-3','Neg'))

gx <- grid.step
while (gx <= w) {
  abline(v = gx, col="gray", lty="dotted")
  gx <- gx + grid.step
}
gy <- grid.step
while (gy <= h) {
  abline(h = gy, col="gray", lty="dotted")
  gy <- gy + grid.step
}

abline(c(TP2,h/w),lty=2)

col1 <- "blue"
points( FP1, TP1, col=col1, type="o")
text( FP1, TP1, "C1", pos=3)
abline(h=TP1, v=FP1, col=col1, lty="dotted")

col2 <- "red"
points( FP2, TP2, col=col2, type="o")
text( FP2, TP2, "C2", pos=3)
abline(h=TP2, v=FP2, col=col2, lty="dotted")

col3 <- "green"
points( FP3, TP3, col=col3, type="o")
text( FP3, TP3, "C3", pos=3)
abline(h=TP3, v=FP3, col=col3, lty="dotted")

Python figure

Code

import matplotlib.pyplot as plt

h = 50
w = 50

grid_step = 10

TP1 = 30
FP1 = 10
TP2 = 20
FP2 = 20
TP3 = 40
FP3 = 20

fig, ax = plt.subplots()
ax.set_xlim(0, w)

(0.0, 50.0)

Code

ax.set_ylim(0, h)

(0.0, 50.0)

Code

ax.set_xlabel("Negatives")
ax.set_ylabel("Positives")

ax.set_xticks([0, FP1, FP2, w])
ax.set_xticklabels([0, "FP1", "FP2-3", "Neg"])
ax.set_yticks([0, TP2, TP1, TP3, h])
ax.set_yticklabels([0, "TP2", "TP1", "TP3", "Pos"])

gx = grid_step
while gx <= w:
    ax.axvline(x=gx, color='gray', linestyle='dotted')
    gx += grid_step

gy = grid_step
while gy <= h:
    ax.axhline(y=gy, color='gray', linestyle='dotted')
    gy += grid_step

ax.axhline(y=TP2, linestyle='dashed')

col1 = "blue"
ax.plot(FP1, TP1, marker='o', color=col1)
ax.text(FP1, TP1, "C1", verticalalignment='bottom', horizontalalignment='center')
ax.axhline(y=TP1, color=col1, linestyle='dotted')
ax.axvline(x=FP1, color=col1, linestyle='dotted')

col2 = "red"
ax.plot(FP2, TP2, marker='o', color=col2)
ax.text(FP2, TP2, "C2", verticalalignment='bottom', horizontalalignment='center')
ax.axhline(y=TP2, color=col2, linestyle='dotted')
ax.axvline(x=FP2, color=col2, linestyle='dotted')

col3 = "green"
ax.plot(FP3, TP3, marker='o', color=col3)
ax.text(FP3, TP3, "C3", verticalalignment='bottom', horizontalalignment='center')
ax.axhline(y=TP3, color=col3, linestyle='dotted')
ax.axvline(x=FP3, color=col3, linestyle='dotted')

plt.show()