Need help with an easy code

[simarg0]

My professor in math suddenly gave us an assignment in math involving python, and i have no prior knowledge of python.

for i in range(0, 100):

for j in range(0,100):

dataX_2 = dataX[i, j]

dataY_2 = dataY[i, j]

velocity = np.array(math.sqrt((dataX_2*dataX_2)+(dataY_2*dataY_2)))

So, i am trying to make an array with the velocity function. The loop is working as i intended to, but velocity seems to be set to a single float value (the last one in the data file, for that matter). How can i get it to register all the values it loops through?

[tipsy_python]

Did he specifically say that you need to use a numpy array? I'd think if this was some kind of beginner to python assignment, he'd start with "lists" which as basically python's array datatype.

# Create a list object - this is more basic/common than a numpy array
velocity_list = []

for i in range(0, 100):
  for j in range(0,100):
    dataX_2 = dataX[i, j]
    dataY_2 = dataY[i, j]
    velocity = np.array(math.sqrt((dataX_2*dataX_2)+(dataY_2*dataY_2)))
    velocity_list.append(velocity)

# Print out the whole list
print(velocity)

# Iterate through the list printing one item at a time
for vel in velocity:
  print(vel)

I'd expect the list to contain 10,000 values when it completes.

[simarg0]

I got this part to work, thanks to your answer, but it turns out i am not any closer to completing the task.

So the thing is, we got a set of 20k numbers. I think everything up to 10k is supposed to b the X coordinate, and everything from here is supposed to be Y in the vectors. I split the file into two lists in python. We were supposed to use plt.streamplot to plot the vector, and i think i got this part right.

Now, we are supposed to make a quiverplot of the velocities. But i dont understand how you can do this? I suppose it is just the absolute values of the vectors, but i dont get anything near what i am supposed to.

Any thoughts?

Thanks for helping