How do you find the difference between numbers in a column in excel using python?

Question

I have an excel sheet of data points in excel that represent how far something moves relative to an origin point. Negative numbers are before the origin and positive are after the organism meets that point and continues moving. I would imagine that I would need to create a loop that goes from one number to the next subtracting it from the previous number.

After I have the differences in the distances want to

• Find the ratio of time stopped to time moving
• Find the average speed during moving times (frame rate is 120 fps)
• Find the maximum speed during moving times
• Find the average duration of movements

EX Data:

0.0003
0.0032
0.0021
0.0012

So far I have imported the data and defined moving and stopped.

#import dataset 
geckomove=numpy.loadtxt(open("SMgecko.csv","rb"),delimiter=",") 
 
#find array size: 427 data points in column 
g=geckomove.shape 
print(g)  # moving=0 stopped=0

Answer 1

Not really clear how the values relate to frames, but taking a simple example, this would give you the difference between each value

import numpy

arr = numpy.array([
  0.0003,
  0.0032,
  0.0021,
  0.0012])

# Offset the values
arr2 = arr[1:]
arr2 = numpy.concatenate((arr2, numpy.array([0])))  # probably better way to do this

arr3 = arr2 - arr
print(arr3[:-1])   # [ 0.0029 -0.0011 -0.0009]

Meaning, between first and second value, there was a 0.0029 difference, then down 0.0011 between the next two, and so-forth.