Counting the number of times a value change signs with R -

I am very new to R but encouraged with it because I find it accessible though I am not a programmer Trying to get the following issue: How many times I get a price change signal in a countdown and then the result will be sorted by the path (The example for table is below - path is a factor). I can understand how to sort the data after eventually receiving them, but so far there is no signal to calculate for the number of numbers - and the one-icon gets a + one Any remedy?

  & gt; Head (Test) Path Instructions 1 1 -3.84089 2 1 -1.12258 3 1 1.47411 4 2 -1.4732 9 5 2 5.4525 6 2 10.161 
 
 I think what you want  
  sum (diff (sign)! = 0)   
 Where  x  is a vector, in your case,  dat $ direction  which you are trying to count sign changes.  
 
  
 If you want to calculate by  path , you can use the  by  function or Use your  data.frame  in a  worth of data  and using  by  abilities 
 example:  
  Value  X  is your original  data.frame    
  # I'm adding another row to the data, Just to show that it works # (i.e., two paths in a different number Provides) X & lt; - rbind (X, c (2, -5)) # Datatable Library (Data Deleticity) DT & LT; - Change the number of changes in datatable (x) #, change each path DT [, change: = sum (difference (sign) = 0 (comment about  factors ): < / H3> 
 If the  direction is     code> factor , it must first be converted to  numeric  You can do this  
  as DT [, direction: = numeric (direction)]   
 Result:  
  DT path direction change 1: 1 -3.84089 1 2: 1 -1.12258 1 3: 1 1.47411 1 4: 2 -1 4732 9 2 5: 2 5.45250 2 6: 2 10.16100 2 7: 2 -5.00000 2