Python: For loops and lists

Question

Given a list x=[-10,-9,-8,-7,-6,-5,-4,-3,-2,-1,0,1,2,3,4,5,6,7,8,9,10] use a for loop to create a new list, y, that contains the value aSin(10a) for each value, a, in list x. Plot the results using plot(x,y).

I have...

x=[-10,-9,-8,-7,-6,-5,-4,-3,-2,-1,0,1,2,3,4,5,6,7,8,9,10]

for a in x:

print sin(a)*(10*a)

The code returns the correct sin values but I'm not sure how to get the values into a new list y..

Any help would be greatly appreciated.

you mentioned in the text that you want a*sin(10a), but you have different thing in the code — rawwar, May 18 '18 at 14:22

score 5 · Accepted Answer · edited May 18 '18 at 16:56

5

Use list comprehensions here

>>> y = [sin(10*i)*(i) for i in x]

edited May 18 '18 at 16:56

rawwar

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answered May 18 '18 at 14:20

akash karothiya

5,736
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this is great. thank you :) – Dan May 18 '18 at 14:28

score 2 · Answer 2 · answered May 18 '18 at 14:20

2

try this

 x=[-10,-9,-8,-7,-6,-5,-4,-3,-2,-1,0,1,2,3,4,5,6,7,8,9,10]
 y=list()
 for a in x:
     y.append(sin(a)*(10*a))

answered May 18 '18 at 14:20

ashish pal

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score 1 · Answer 3 · answered May 18 '18 at 14:21

1

the following code works

x=[-10,-9,-8,-7,-6,-5,-4,-3,-2,-1,0,1,2,3,4,5,6,7,8,9,10]
y = [i*sin(10*i) for i in x]

answered May 18 '18 at 14:21

rawwar

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score 1 · Answer 4 · answered May 18 '18 at 14:21

1

x=[-10,-9,-8,-7,-6,-5,-4,-3,-2,-1,0,1,2,3,4,5,6,7,8,9,10]
y=[]
for a in x:
    y.append(sin(a)*(10*a))

Should work but do try to learn python!!

answered May 18 '18 at 14:21

Paula Thomas

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score 0 · Answer 5 · answered May 18 '18 at 14:22

0

Try list comprehension:

y = [a * sin(10*a) for a in x]

Hope that helps.

answered May 18 '18 at 14:22

ohduran

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Python: For loops and lists

5 Answers5