[SciPy-user] plot curve of a series of equations

Christopher Barker Chris.Barker@noaa....
Fri Apr 24 16:55:54 CDT 2009


>> eqs = [
>> ['24 + 18.75*x + 4.79616e-013*x**2 + 31.25*x**3', 7.800, 7.600],
>> ['28 + 22.5*x + 5.68434e-013*x**2 + 0*x**3', 8.000, 7.800],
>> ]
>>
>> for i in eqs:
>>      xr = np.linspace(i[2], i[1], 10)
>>      x = xr - i[2]
>>      y = eval(i[0])

eval makes me nervous. One of the nifty things about python is that 
functions are objects too, so you can do something like:
(untested)

eqs = [
    (lambda x: 24 + 18.75*x + 4.79616e-013*x**2 + 31.25*x**3,
     7.800, 7.600),
    (lambda x: 28 + 22.5*x + 5.68434e-013*x**2 + 0*x**3,
     8.000, 7.800),
    ]

for f, x1, x2  in eqs:
       xr = np.linspace(x1, x2, 10)
       x = xr - x2
       y = f(x)


If the function are more complicated, you can use def, rather than 
lambda, and still put them in list or whatever.

-Chris







-- 
Christopher Barker, Ph.D.
Oceanographer

Emergency Response Division
NOAA/NOS/OR&R            (206) 526-6959   voice
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Chris.Barker@noaa.gov


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