Would Anonymous Functions Help in Learning Programming/Python?

[Ron Adam]

Scott David Daniels wrote:
> Cristian wrote:
>> On Sep 21, 3:44 pm, Ron Adam <r... at ronadam.com> wrote:
>>
>>> I think key may be to discuss names and name binding with your friend.
> 
> Here's an idea:
> 
> import math
> 
> def sin_integral(start, finish, dx):
>      total = 0.0
>      y0 = math.sin(start)
>      for n in range(1, 1 + int((finish - start) / float(dx))):
>          y1 = math.sin(start + n * dx)
>          total += (y0 + y1)
>          y0 = y1
>      return total / 2. * dx
> 
> 
> def cos_integral(start, finish, dx):
>      total = 0.0
>      y0 = math.sin(start)
>      for n in range(1, 1 + int((finish - start) / float(dx))):
>          y1 = math.cos(start + n * dx)
>          total += (y0 + y1)
>          y0 = y1
>      return total / 2. * dx
> 
> generalize and separate the integration technique from the
> function it integrates.


How about this?

It's based on the apple basic program example in How to Enjoy Calculus.


    Ron




import math

def integrate(fn, x1, x2, n=100):
     # Calculate area of fn using Simpson's rule.
     width = float(x2 - x1) / n
     area = fn(x1)
     if n % 2 != 0:     # make sure its even
         n += 1
     for n in range(1, n):
         x = x1 + n * width
         if n % 2 == 0:
             area += 2.0 * fn(x)
         else:
             area += 4.0 * fn(x)
     area += fn(x2)
     return area * (width / 3.0)


def fn(x):
     return x**2

print "Area of fn:", integrate(fn, 0, 2)

print "Area of cos fn:", integrate(math.cos, 1, 2)

print "Area of sin fn:", integrate(math.sin, 1, 2)




Area of fn: 2.66666666667
Area of cos fn: 0.0678264420216
Area of sin fn: 0.956449142468