from math import *
from cmath import *
from matplotlib.pyplot import *

# Input table of values
print("Compute a Riemann Sum from a")
print("table of value (separate")
print("values using commas)")
xs = [float(v) for v in input("Enter x-values: ").split(",")]
ys = [float(v) for v in input("Enter y-values: ").split(",")]

# Select a type of sum
print("Pick type of sum")
print("L (Left), R (Right), B (Both)")
print("*no graph provided for Both")
rtype = input("Riemann sum type: ").strip().upper()

# Function to compute sums
def riemann_sum(xs, ys, rtype):
    total = 0
    for i in range(len(xs)-1):
        dx = xs[i+1] - xs[i]
        if rtype == "L":
            height = ys[i]
        elif rtype == "R":
            height = ys[i+1]
        else:
            height = 0
        total += height * dx
    return total

# Case B (Both): compute & print values only
if rtype == "B":
    left = riemann_sum(xs, ys, "L")
    right = riemann_sum(xs, ys, "R")
    print("Left Riemann Sum:", left)
    print("Right Riemann Sum:", right)

else:
    # Single type chosen → compute + plot
    result = riemann_sum(xs, ys, rtype)
    print(rtype + " Riemann Sum:", result)

    # Plot
    xmin=int(min(xs)-2)
    xmax=int(max(xs)+2)
    padding=max(5,.25*(max(ys)-min(ys)))
    ymin=int(min(0, min(ys))-padding)
    ymax=int(max(0, max(ys))+padding)
    axis((xmin,xmax,ymin,ymax))
    scatter(xs, ys, color="red")
    plot(xs, ys, color="blue")
    text(xmin+.5,ymax-1,rtype + " Riemann Sum:"+ str(round(result,3)))

    # Draw rectangles
    for i in range(len(xs)-1):
        x0, x1 = xs[i], xs[i+1]
        dx = x1 - x0
        if rtype == "L":
            height = ys[i]
        elif rtype == "R":
            height = ys[i+1]
        bar(x0+dx/2, height,dx)

    show()